Is camera lens focus an exact point or a range?

Question: I have often wondered if the focus of a lens at a particular focal length is an exact point or a range within a few millimeters. This becomes all the more important when manually focussing. How far from the camera's point of focus may a subject be and still appear crisp?
Comment: [Does a "point" even physically exist?](https://www.shiftfrequency.com/quantum-jumping-weirdness/)
Comment: What wavelength of light?
Comment: @xiota that's a good point, and those exist...
Comment: what have you tried to answer this question yourself? that will inform people here of what can be moist helpful
Answer: There's only one distance that is in sharpest focus. Everything in front of or behind that distance is blurry. The further we move away from the focus distance, the blurrier things get. The questions become: "How blurry is it? Is that within our acceptable limit? How far from the focus distance do things become unacceptably blurry?"
What we call depth of field (DoF) is the range of distances in front of and behind the point of focus that are acceptably blurry so that things still look like they are in focus.
The amount of depth of field depends on two things: total magnification and aperture. Total magnification includes the following factors: focal length, subject/focus distance, enlargement ratio (which is determined by both sensor size and display size), and viewing distance. The visual acuity of the viewer also contributes to what is acceptably sharp enough to appear in focus instead of blurry.
The distribution of the depth of field in front of and behind the focus distance depends on several factors, primarily focal length and focus distance.
The ratio of any given lens changes as the focus distance is changed. Most lenses approach 1:1 at the minimum focus distance. As the focus distance is increased the rear depth of field increases faster than the front depth of field. There is one focus distance at which the ratio will be 1:2, or one-third in front and two-thirds behind the point of focus.
At short focus distances the ratio approaches 1:1. A true macro lens that can project a virtual image on the sensor or film that is the same size as the object for which it is projecting the image achieves a 1:1 ratio. Even lenses that can not achieve macro focus will demonstrate a ratio very near to 1:1 at their minimum focus distance.
At longer focus distances the rear of the depth of field reaches all the way to infinity and thus the ratio between front and rear DoF approaches 1:∞. The shortest focus distance at which the rear DoF reaches infinity is called the hyperfocal distance. The near depth of field will very closely approach one half the focus distance. That is, the nearest edge of the DoF will be halfway between the camera and the focus distance.
We must also remember that hyperfocal distance, like the concept of depth of field upon which it is based, is really just an illusion, albeit a rather persistent one. Only a single distance will be at sharpest focus. What we call depth of field are the areas on either side of the sharpest focus that are blurred so insignificantly that we still see them as sharp. Please note that the hyperfocal distance will vary based upon a change to any of the factors that affect DoF: focal length, aperture, magnification/display size, viewing distance, etc. For why this is the case, please see:
Why did manufacturers stop including DOF scales on lenses?
Is there a 'rule of thumb' that I can use to estimate depth of field while shooting?
How do you determine the acceptable Circle of Confusion for a particular photo?
Find hyperfocal distance for HD (1920x1080) resolution?
Why I am getting different values for depth of field from calculators vs in-camera DoF preview?
As well as this answer to Simple quick DoF estimate method for prime lens
Comment: Maybe also [Technically, why is the out of focus area blurred more when using a bigger aperture?](https://photo.stackexchange.com/questions/13456/technically-why-is-the-out-of-focus-area-blurred-more-when-using-a-bigger-apert) and [How can I take a photo with everything in focus with my DSLR?](https://photo.stackexchange.com/questions/30976/how-can-i-take-a-photo-with-everything-in-focus-with-my-dslr)
Comment: Is there not a factor in acceptable sharpness related to the resolution of the sensor or film speed (for analog)? As in, if the resolution of the sensor is... to abuse language, "coarser than the blurriness at a given distance", then the sharpness at that distance will appear to be as sharp as possible given the resolution/speed. Right? Perhaps this is getting very pedantic with modern digital sensors, but perhaps for cheap cameras and/or low lighting situations it is relevant.
Comment: Yes, there is. But it is generally several times smaller than what the human eye can perceive at typical display sizes and viewing distances. Low lighting has nothing to do with it. It's the detail destroying poorly applied noise reduction applied to many images taken in low light that softens everything to the same level of blurriness.
Comment: To be a bit more specific, even with a modest 22MP FF sensor the *Circle of Confusion* we use for an intended display size of 8x12" viewed from 12" is about 4-5 sensels (pixel wells) in diameter. That's why when we go pixel peeping on our monitors we can see that some things that look in focus at 8x12" are actually blurry when we view one small part of them on our 24" HD monitors at the equivalent of 60x40" enlargement.
Answer: Imagine a wall some distance from your camera — a flat wall with no depth, and you're facing it straight on. Lens focus is like that: everything in that exact plane is in focus.
(This is a simplification. For real-world lenses this isn't perfectly flat. In reality, a number of unavoidable optical aberrations keep perfection at bay, but for a basic understanding the idea of a flat plane is good enough.)
So, the sharpest focus is at that plane. Focus points on the camera are used to tell the focus system where to look for increased contrast, and (assuming the autofocus works) everything in the same plane should also be in sharp focus. If you focus closer, it's like bringing the "wall" closer to you; focusing further away is pushing it back. The camera can't focus on multiple points that aren't in the same plane. There's just one focus distance. (Autofocus systems offer multiple focus points, but these are just different possible areas of the frame to focus on. If the objects at those points are at different distances, only one point can ever be in perfect focus.)
But, sharp focus doesn't immediately go from that to unrecognizable blur. Each point which should be sharp on your sensor is actually a tiny circle, and the further away from perfect, the larger that tiny circle becomes. (See What is the "Circle of Confusion?").
If the circle is smaller than you can detect (like, smaller than the pixels on your sensor, or smaller than your eye can see in a final print), something which may be closer or further from the ideal "wall" of sharp focus may be literally indistinguishable from perfect sharpness. Additionally, even outside of the limitations of your camera and imaging system, there's some amount of very slight blur that we're willing to accept as "good enough". This where we get the concept of depth of field. Rather than a plane with no thickness, think of an imaginary thick wall with depth closer and further than the distance you're focused at. Everything in that is "within the depth of field", and therefore considered in focus.
(But don't make the mistake of thinking that this imaginary thick wall has hard borders — it's really a "soft" zone where the borders are a definite judgment call.)
In general, smaller apertures (higher f-numbers) provide more depth of field. (See Technically, why is the out of focus area blurred more when using a bigger aperture?)
Comment: Yes. Much better. I'd still like to see the removal or "real world", because even theoretically perfect lenses are also subject to the classic optical aberrations.
Comment: Real world as opposed to [spherical cow world](http://www.physics.csbsju.edu/stats/WAPP2_cow.html). The flat plane of focus is like the spherical cow — a useful model that's a good enough approximation for many cases.
Answer: Geometric optics teach us to expresses that a lens is only able to form a sharp image of an object at a given focus point. Objects nearer or further as to distance will image as unsharp. However, as a matter of common observation, objects before and behind the distance focused on likely appear sharply focused. The reason is, there  exists a span before and behind the point of focus that reproduces acceptably sharp. This span is called "depth-of-field".
The lens handles each point of the subject individually. By point, we are talking about a spot so tiny it has no dimension. The job of the lens is to project an image of this point on the image plane. Because of residual uncorrected aberrations and inadequate focusing, the image of points is never reproduced as points. Instead, all points reproduce as circles. These are called circles of confusion because they have scalloped boundaries and are juxtaposed alongside adjacent circles of confusion.
It is the size of these circles that is the determining factor as to whether we pronounce an image as tack sharp or blurred. If the circles are tiny and below our ability to resolve them as circles, we pronounce the image "sharp". If these image points are seen as circles and not dimensionless points, we pronounce the image unsharp.   For the average person with good vision, viewing a photograph in good light, these circles of confusion must be no larger than 2/100 inches (½ mm). when viewed from 20 inches
This is the stuff of "depth-of-field".
Answer: For each particular wavelength and each front lens radius (assuming perfect radial symmetry of the lenses), focus is an exact distance, given that the sensor is a perfect spherical surface with the center being in the focal plane.  Wait, it isn't.  And we are not working with monochromatic light either.  And if the focus distances for various front lens radii don't match perfectly, we get different performances at different apertures.
Depth of field is calculated assuming a perfect lens model and an acceptable "circle of confusion".  The truth is that lenses are not perfect.  So the "circle of confusion" will be dwarfed by chromatic longitudinal (and lateral) aberration and spherical aberration and lens convergence problems in practice, all of those determining a range where you could not distinguish meaningful levels of sharpness irrespective of sensor resolution.
The "circle of confusion" based depth of field calculation has the advantage of working from well-determinable numbers (at least when using digital sensors with fixed pixel pitch) but it omits taking into account the quality of the optics.  If the optics were able to let light through the entire aperture at all visible wavelengths from a single point at focusing distance converge to a single point on the sensor (which actually has non-zero depth of its photon-converting surface, throwing another spanner in the works), you could talk about exact focusing distances.


How to prepare good coffee during an outdoor trip?

Question: I am planning some hiking/climbing trips this year so I started looking into portable espresso machines. I found these products and also this ESPRESSO ON THE GO (this one actually got me super excited and I'm definitely getting one). No idea what the exact differences are apart from the price - The first one is much more expensive. I was wondering whether there are any old school tricks to prepare good coffee on an outdoor trip that don't require you taking too much equipment with you - I would prefer espresso but I realize that this is probably unrealistic. Also, what type of beans would you take on such a trip and how would you store them?
Comment: Higher altitude will [reduce the boiling point of water](http://en.wikipedia.org/wiki/High-altitude_cooking) so if you use nearly-boiling water at higher altitude, you'll be using lower temperature water than nearly-boiling water at sea level. This will certainly make a difference for coffee extraction above the 2500m / 8000ft range (boiling point 92C/195F). @hardmath - good point! Other reasons?
Comment: Is this a high altitude camping/hiking trip?
Comment: @hoc_age:  No other point, although speaking of high-altitude, this month's Scientific American (Apr. 2015, p.18) has a brief note about the International Space Station getting its first espresso machine. "ISSpresso is the product of a collaboration among the Italian Space Agency, Italian engineering company Argotec, and Lavazza, a 120-year-old, Turin-based coffee roaster."
Comment: So far the Highlands in Scotland are the highest planned altitude. Would there be a difference in preparation or are you asking because of the flavor perception in high altitudes?
Comment: Ah, I would have never thought about that... Good point to keep in mind. The highlands should be lower than that.
Comment: @hardmath - Speaking of ISSpresso -- [there's a question about that](http://coffee.stackexchange.com/questions/282/what-changes-need-to-be-made-to-espresso-machine-so-it-can-function-properly-in)! Good links in [this answer](http://coffee.stackexchange.com/a/283/262).
Answer: I'm going to focus on the "old-school" aspect of your question.
From my perspective/experience, the classic way of producing "camp coffee" is a percolator. To use this device, you put grounds in a basket on the top, water in the bottom, assemble the apparatus, and put it over a heat source (e.g., camp fire, stove, etc.). If you want a stronger brew (as it sounds like you do), you can also use a moka pot (some call this a "stovetop espresso maker", though I don't care for that term) -- there are some very compact moka pots like this one that are targeted for backpacking/camping. This will give you very good moka-pot-strong espresso-like coffee, but you won't mistake it for espresso out of a professional espresso machine. You get the full experience of brewing a pot of coffee in the wilderness, which I enjoy. See also my related q/a on the difference between a percolator and a moka pot. Those are my preferences for camp coffee.
For a little more technology, you can use integrated heater/container systems like the JetBoil; they also have small accessories like this French press insert so you can minimize the extra gear (e.g., you can use the setup for heating water for other cooking, and (separately) use it to make coffee).
On the extreme end of low-weight and low-technology spectrum, you could use instant coffee or try coffee bags such as these, which are like tea bags, except that they are filled with coffee. You could even make your own coffee-bags (see instructables and MtBoE). Though there are tradeoffs and reasons you might not want to do this, from Seasoned Advice. These single-serve coffee bags have the advantage of minimal clean-up, and the whole package may be compostable. Also you don't have to worry about hot gear if you're packing up to get on the trail quickly (e.g., backpacking). Bags and instant are passable, ultra-light substitutes for actual coffee that get the job done but are less enjoyable to drink (for me).
Storage of beans and/or grounds is tricky -- especially already-ground coffee goes stale very quickly. You can minimize the damage by keeping everything sealed and dry. See also questions about storage in general and vacuum-sealing. You could always use a hand grinder, but that's more gear and more weight.
In sum: I go "fast and light" for coffee on the trail: gear that's reasonably light, that I can use quickly (for me, this is moka pot) so I can get the caffeine-dose done and get back on the trail. Pre-grind the coffee into a zip-top bag and evacuate as much air as possible. Deal with the slightly-stale taste and focus on being outdoors!
Comment: Thanks for all the tips. The moka pot seems like something I would go for at this point, at least before the minipresso becomes available, which I have to try :) Hmm, I've seen vacuum tupperware  containers in a local store - they have a pump so you can suck the air out after closing. These might be a good option for proper storage.
Comment: @schvaba - Moka is certainly my go-to -- if you haven't used one much, practice with it before the trip! See other questions tagged [tag:moka] also. I'd still go for the plastic bag to reduce the size and gear over a vacuum box, but it sounds like it's worth a (pre-trip!) test also. If you discover something interesting, put a q/a here on [coffee.se]! Fun question.
Answer: I think an AeroPress would work great on a trip.  Just need hot water.
AeroPress Video Tutorial How To :: Inverted AeroPress Video Tutorial (YouTube)
See also other questions tagged aeropress.
Comment: [AeroPress](http://aerobie.com/products/aeropress.htm) sounds like a good idea. Would you kindly describe the video link?  Is it about outdoor use of the AeroPress, as pertains to this question?
Answer: I answered a previous question about making coffee with eggs that might also address your question.  The method is very simple and I see no reason why you couldn't do the same thing without the eggs.  Here is my original answer below:

I don't know any history behind the practice but I learned it myself during a rafting trip down the Grand Canyon back in the early '90's. The method was to put a couple of fistfuls of loose grounds in one of those giant porcelain coffee pots that look like they came out of a Zane Grey novel. Follow with two whole uncooked eggs and with a big metal spoon, stir the whole mess in the bottom of the pot, breaking the eggs and mixing it well with the dry grounds. Fill the pot with cold water and put on a hot fire until the thing boils. Take the pot off the fire and open the lid, dribbling about a cup of cold water over the top of the liquid inside. Somehow this settles all the solids to the bottom of the pot and the coffee really tasted pretty good. My take was that the egg sort of smoothed out any harshness the crude method would have introduced to the coffee otherwise. The grounds pretty much stay at the bottom of the pot and were not really a problem in the cup.

Your method might inlcude a smaller pot and less coffee grounds, but all brew methods are essentially just soaking ground coffee in hot water.  A small French press might also suit your needs just fine.  You should test out your method before you go, though.
Comment: I suppose if you're taking eggs on the trail this could work, but you say "without the eggs" -- aren't the eggs part of the "magic" here? If you're suggesting simply to boil then decant coffee grounds, focus just on the "magic" of the cold water, which you say somehow settles the solids -- that itself sounds like your major point, and is a great answer to this question if it works! If you're not recommending to use eggs, take out the egg talk! :)
Comment: I've read posts about egg coffee but I've never tried. I'll give it a shot, sounds very interesting :)
Comment: @schvaba - It's surprisingly good for how crude a method it is.  Speculation is that the egg somehow cancels out whatever bitterness comes from the method, but I've not tried that method without the eggs so I don't really know.
Comment: A few other recommendations, if you don't mind: Simply link to your answer (as I edited-in above) and paraphrasing instead of copying wholesale, [as suggested here](http://coffee.stackexchange.com/help/referencing). Also, if you want to reply to a comment, please tag the user (as I edited into your comment); the poster of the question or answer you're commenting on will always get notified (as you did without me tagging you here). See [editing help](http://coffee.stackexchange.com/help/editing) for more. Great points, and welcome to [coffee.se]!
Answer: I agree that the Aeropress is a good option for making your coffee - I actually take one of those with me when I go on road trips so that I don't have to rely on terrible gas station coffee! I also found this article on travel coffee makers that might help you out. As for storing your beans, it needs to be something that is air tight and dark so that the light doesn't hit the beans.
Comment: For links, it's always helpful (and better received!) to give a brief summary. Can you edit your answer with a few highlights of the article you linked?
Answer: I recommend the bialetti. I think thats how its spelled.  Its a stove top device (I suppose you could put it in a fire, too).  It makes some of the BEST homemade coffee Ive ever had. Highly recommended.  Its essentially an espresso machine, I put regular non-espresso coffee in it though. Still awesome.  It's non-electrical, the one I have is no more than a half-pound heavy and about 6 inches tall and 3 or 4 inch diameter base.
Comment: Bialetti is a brand of moka pot. See also the other answers to this question about moka and the [tag:moka] tag for more on this. Welcome to [coffee.se].


negative verb confusion

Question: Slightly mundane question here. Do negative verbs  translate as x "does not" do this action or simply "not" e.g 食べない "not eat" as opposed to "does not eat". The reason I ask is because On Tae kim's site all the verb examples are translated as "does not", When suddenly 買わない becomes "not buy" - which is it? I know it's a silly a question, but I'm pretty curious, so I'd really appreciate any answers.
Comment: If you expect to be able to translate between English and Japanese in a word-by-word way, I'm afraid you're in for a nasty surprise.
Comment: What would this mean, what is the difference? Negative constructions with ない are themselves conjugatable again, which is a feature shared by the English expression "does not do , eg. _食べなかった_ -> _did not do _.
Answer: In English, the auxiliary verb do is a meaningless verb that is inserted for various reasons.  For example, direct questions require an auxiliary verb in modern English:

 1a. *Like you the movie?
   1b. Do you like the movie?

When you form an English question like this, the subject and auxiliary swap places.  But the lexical verb like isn't an auxiliary, so example 1a is ungrammatical.  You insert do so that you have an auxiliary to switch with the subject.
And in modern English, you need an auxiliary to add the negative not or negative affix -n't:

 2a. *She takes not the money. / *She takesn't the money.
   2b. She does not take the money. / She doesn't take the money.

The examples in 2a don't work because take is a lexical verb.  In this kind of English sentence, you can only negate an auxiliary verb, so you insert the meaningless verb do.

Japanese is completely different.  It has a negator -(a)nai which attaches directly to verb stems.  There's no need to insert anything like do, so whether or not you translate it with do depends on what's required in English.  It has nothing to do with Japanese.
To form the negative in Japanese, attach -(a)nai to the stem of a verb:
 食べる  tabe-ru
 食べない tabe-nai

The stem tabe- ends in a vowel, so you add -nai without the (a).
 話す   hanas-u
 話さない hanas-anai

The stem hanas- ends in a consonant, so you add -anai with the (a).  Adding this extra vowel prevents you from saying the consonants /s/ and /n/ with nothing in-between, which Japanese doesn't allow.
Your example 買う is a consonant stem verb, too, even though it doesn't look like one.  The stem is kaw-, so you insert the (a):
 買う   kaw-u
 買わない kaw-anai

The reason this seems weird is that /w/ disappears before every vowel except /a/.  So the /w/ disappears from kaw-u, and you're left with kau (買う).
The main exception to this pattern is ある, which becomes ない instead of *あらない.  And there are other negators (such as ん in ません, used to form a polite negative).  But I'm limiting this discussion to ない, since that's the negator you asked about.
As you can see, there's nothing corresponding to do in these Japanese examples.  Whether you translate these with do or not depends entirely on the requirements of English, and has nothing to do with the Japanese.
Comment: @istrasci That's exactly what's wrong with it.  It's not modern English.  (It's fine, of course, if you want to use an archaism!)
Comment: I see nothing wrong with `She takes not the money`, other than it makes you sound like you're from Victorian-era England.
Comment: Well that doesn't make it "wrong", just "out of use".  Splitting hairs I guess...  Although I now see that you said, "In modern English", which I guess I missed before.
Answer: Tae Kim sometimes uses over-literal translations.  I'm guessing the one that confused you was "As for me, not buy" (私は買わない).
Without context, this could mean:
1) A specific statement about the future: I'm not going to buy/I won't buy (thing we were talking about)
2) A more general statement about your habits: I don't buy (thing we were talking about)
Comment: Don't know why, but I have seen other people confused by some of by some of the Tae Kim translations, so it's not just our OP.
Comment: Ugh.  "(1) アリスは食べない。- As for Alice, does not eat. […] (5) 私は買わない。- As for me, not buy."  Why did the author write _does_ in (1)?  It is not the correct English anyway, and comparing these two sentences, the OP's confusion is pretty much expected.

negative verb confusion


Where can I find historical natural disasters by country?

Question: I'm trying to find a dataset that contains number of historical natural disasters by country in the longest lapse of time possible. Would appreciate your help.
Answer: In the academic literature EM-DAT seems to be the standard.
It is quite a comprehensive dataset covering ~21,000 disasters worldwide and going back to 1900 (don't know if that is historical enough). It also classifies disasters according to group and subgroup which can be useful.
Answer: Natural Disasters
Includes data and analysis

Natural disasters - statistics & facts

Natural Hazards Data, Images and Education
NCEI archives and assimilates tsunami, earthquake and volcano data to support research, planning, response and mitigation. Long-term data, including photographs, can be used to establish the history of natural hazard occurrences and help mitigate against future events.


EQing the reverb

Question: i would like to know if you guys EQ a reverb, if so what parameters do you keep in mind while doing so? everytime i try to EQ a reverb i end up fiddling with it without getting proper results..i have tried using Rverb.
or may be can someone explain why we need to eq a reverb in first place?
Answer: I almost always end up EQing my reverbs, although sometimes convolution reverb presets work without alteration. It truly depends on what you are sending to the reverb and what else is happening in the mix. Un-EQed reverb usually covers the full frequency spectrum, and if you're talking about many elements in a mix then adding broadband reverb can result in a layer of distracting "soup" that muddies up your other mix elements.
I would suggest experimenting with putting the EQ before the reverb in the signal chain. If you feel that there is too much bass boominess in your reverb, for instance, try inserting an EQ before the reverb and shelving out the bass there—then perhaps add a subtle boost in the frequency range where you want the reverb to sit. It makes for a much more natural reverb sound when it works. If you still feel you are not getting the results you're looking for, consider a different reverb preset or plugin (if this is available to you).
If you know you have the right setup and it's still not working for you, then add an EQ post-reverb. Always start by working in simple, broad EQ strokes (high- and low-shelves are your friend) as this will keep the overall tone of the reverb more natural.
Good luck!
~Matt
Answer: I use EQ on a reverb to try and recreate the surfaces that are present in the room that I am trying to simulate. If there is plaster board, I will roll of some of the top end, if there is stone I roll off more of the bass.  If the space is mostly glass then high mids will be important.  I will also consider the likelihood of room modes and EQ accordingly.
Answer: I do a good amount of music as well as sound design and mix and yes I eq verb much of the time, even if that means using the shelving parameters that exist in many verb plugs. Also like Matt mentioned, often times it is a matter of eqing the signal going into to the verb. It is common for me to filter a bit of the bass out of the signal before it hits the verb to keep it more clean down low. As a generality, things can get muddy quickly when verb is applied to bass. Washing out the low end is often times trouble so applying a high pass to a desired taste to the signal going in can help keep a mix clean down low and still give you nice ambiance up above, this is especially true if you are bussing multiple signals/channels into one verb on an aux for example. You can then push more reverberant signal if you like without muddying up your low end.

EQing the reverb


Help needed in choosing video production device for use with Matterhorn Capture Agent

Question: In our institution we need to record every class hours and upload it to our Matterhorn server with schedule recording, so i need a good video capture card which need to support a fixed camera and input device for mic and projector and a VGA option, If i'am i scheduled for a class it will automatically record the content and send to Matterhorn server and it will produce the video to other user interface to get watch could any one there to help me out to find a good capture card, asking here because you experts are in video production and you all sure know which card will provide the above requirements.   Thank you..
Answer: One of the best resources you will find for this is probably the Matterhorn documentation itself. The Capture Agent Hardware page has samples of hardware that was used at a number of schools that have implemented capture agents for Matterhorn.  It appears that the Epiphan VGA2USB is the near universal standard for VGA capture.  There seems to be a wider range of video capture devices.
Personally, I'd probably take a look at seeing if the Black Magic Intensity or Matrox MXO2 works with the capture agent, but there are also other listed devices there such as capture devices from Hauppauge or Bluecherry which have actually been used successfully already.
Comment: Yes i have seen the capture agent hardware from Matterhorn, but it seems to be some old more than 2 years, so what i need to be up-to-date with any other compatible cards. at first we need to test before deploying in real environment.
Comment: Thanks a lot @AJ Henderson for Bluecherry, very cheaper than other brand let you know in future if any help needed for me.


Estimate building time for a given LEGO set

Question: I'd like to be able to estimate better how much time a LEGO set will take me to build.
Are there any resources online that indicate average or fastest building times for a given set?
I suppose it also depends on type of set (for younger or for adult builders, Technic or System,...)
What would be your estimate given the amount of elements in a set and type of set?
Comment: Sometimes, set reviews will include a build time as well (depending on the reviewer), so looking for reviews can be a good place to start. But I suggest just getting a feel for how fast you build on average (in parts per hour eg.), and that'll give you a ball park number for any set (which you can then adjust for difficulty if needed). A rough guess could be around 10-20 seconds per part, or somewhere in the range of 200-400 parts per hour.
Comment: Do you have couple of sets in mind? Time it takes to build will wildly depend on experience (how much you know your elements and their colors) and the type of parts you have in a set. Building biggest Technic sets for the first time will take considerably longer than having it as, say, 5th build. And even if you building same sized (parts wise) Technic/System/Creator/Mosaic set each will take different amount of time.
Comment: @MichaelVerschaeve : I haven't created an answer because I don't feel confident my experience can be translated to a general rule. It depends on too many factors. That said, finishing near half of a 2500 part set in an afternoon (assumed to be around 4 hours), is right in the middle of the rough estimated range I mentioned above. So at least you'll be better at estimating for future builds !
Comment: @Alex, the set I had in mind was the recent ideas globe set, only having today in the afternoon time for it, I was wondering if I could build it in 1 sitting before having to start a busy work week. I totally miscalculated, didn't even finish half of it.
Comment: @SanderDeDycker, I think your comment should be an answer instead.
Comment: "fastest building times for a given set" If there are sites tracking this, I'd imagine multiple people will start speedrunning some of the popular sets. Which wouldn't help you much for an average estimate.
Comment: @Mast Yes, but I'm also interested in speed building... seems to overlap too much to ask a separate stack echange question.
Answer: As others have said, there are probably too many factors to say how long a build will take. But, I thought it would be good to compile a list of factors that affect build time. Feel free to add to the list.
The Lego building process can be divided into two sub-processes; searching, and assembly.
Factors that affect searching time:

Number of parts in the pile (mixing numbered bags will increase searching time)
Experience of elements and colours
Any prior sorting of parts by size/colour (will have an overhead time cost, so only useful for large builds)
The distribution of parts (having many unique parts will take longer)
Eyesight and lighting
Determination
If the set is incomplete it can take considerable time to realise

Factors that affect assembly time:

Number of steps
Experience (both of the specific set and in general)
Building of symmetric/repeated sections in parallel
Build complexity
Dexterity and hand-eye coordination
Determination
Errors in Lego instructions (very occasional)
Answer: I am not sure it is possible to give specific guidance based on simple characteristics like part count or theme. In addition to the factors of the person (or people) undertaking the build raised in the comments, design also makes for wildly different building times.
For example, any set that has bilateral symmetry can be built comparitively quickly by building both sides at the same time even if they mirror each other. Sets that are not symmetrical will often take nearly twice as long. Another more obvious example is the use of advanced techniques that can sometimes make build time much longer, sometimes can drastically reduce complexity and build time, and sometimes have no effect.
Set type and part count do not take account of either those or similar factors like modularity and inclusion of large parts like BURPs or chassis. Labeled age range and part count can probably, at best, simply give a relative indication and no more.
Answer: I haven't checked how long it takes my 7 years old daughter based on number of pieces, but I saw she needs about 5 minutes per EUR of the set (with set prices in 20-50 EUR range; Friends mostly). This is for a new freshly opened set.
So, I would guess about 2 min/EUR for an adult that has built some sets but isn't a Lego fanatic. I haven't actually timed myself, though. So, I estimate a 10 EUR set would take about 20 minutes to build, a 100$ one would take slightly more than 3 hours etc.
Transferring these numbers to number of pieces per hour, at 10c/piece it gives ~300 pieces/hour. This sounds reasonable enough to me at first glance, but it is a fairly inaccurate method - though I believe all such estimation methods are.
Note this is only for assembly. Old large sets are slightly slower as all pieces are mixed together instead of being in bags, but it probably shouldn't slow you down too much.
But if you need to find pieces with many sets mixed together, well, 10 sets is a problem, 100 is a nightmare. You should probably sort pieces first (by color, type or whatever else you prefer). And after sort you are still looking at a much longer build.
Answer: First you need to sort the pieces. So lets say you can sort 12 pieces per minute, then you later need to find them which is probably 6 pieces per minute and assemble them like 3 pieces per minute. So in total you need 7 minutes for 12 pieces. So in 4 hours you can do about 400 pieces.
It is a veeery rough estimate.
Comment: This is rough, very rough. This doesn't take in to account many things that reduce timing drastically. I know not everyone is as familiar with LEGO bricks as LEGO fans are, but 4 hours for 400 pieces set is way too much in most cases. [School Day (60329)](https://brickset.com/sets/60329-1/School-Day) is just for the reference, to understand what ~400 piece modern set looks like. Another example is when you assemble big set, say Technic, you may be asked to put a lot of pieces in single step (116 pieces for set #42131, step 997), which doesn't take an hour to do.
Comment: This answer does not consider that some people might not even sort the pieces before building, or do so only roughly.
Comment: @Zovits, new sets I don't sort, they come in numbered bags which contain few enough different elements that the time spent sorting won't be compensated by the faster building imho. Second hand or older sets I definitely sort. Some people enjoy building in "hard mode" where they throw all bags from all steps together, I don't... Also, at whoever downvoted, the user shared his/her perspective/experience, he/she shouldn't be downvoted for that
Answer: I would say I do about 300 to 500 pieces per hour.
Comment: Hi Klaus and welcome to Bricks.SE! Do you base your estimate on personal experience, calculations or other sources? Could you please elaborate?
Answer: Its a correlation between number of parts + the set weight (to incorporate whether its many small pieces or rather few big pieces).
Comment: Hi MervX97 and welcome to Bricks.SE! Could you please elaborate on your answer? I mean it is not clear to me whether the weight you mention would positively or negatively correlate with either the piece size or the estimated building time.


Is it possible to convert a Las /Laz file into an STL or OBJ file?

Question: I would like to know if there is any tool/library (preferably python based) that could be used in parsing a Laz file to extract info that is normally found in 3d object files such as vertices. Which could be used to create printable 3d mesh.
I already tried Laspy and I could get the  x,y,z data from it but it is not a vertices info but rather a scale info. So I would either need a tool to give that or an algorithm for getting vertices from the data  from laspy.
Comment: It is working @Durodola Opemipo ?
Answer: Given that LAS/LAZ is LiDAR point cloud data, there is a GIS tool called las2tin to convert these files to a triangle based mesh called Triangular irregular networks or TIN by the GIS community. Other GIS tools should be able to do the same, for example ArcGIS.
Once you have the mesh, Google should be able to help you find a way to convert the TIN to an STL. You will need to scale down the STL after creation, as the TIN will probably be at 100% scale.
One example workflow for converting LAS data into an STL is:

Using ArcScene: open DEM > convert to TIN > export to VRML
Using MeshLab: open VRML > export to STL
Using Meshmixer: extrude base > scale to fit standard printing parameters > save as finished STL

More details for the process that I got from Google are available here


What is the significance Laylatul Qadr?

Question: Why is Laylatul Qadr an Important night for Muslims? Please quote from the Qur'an or Hadith.
Answer: Laylatul Qadr is translated into the night of destiny, another translation is The Night of Power, there are many translations there is The Night of Decree, The Night of Value and so on.  Laylatul Qadr is the night in which the Qur'an was revealed:

إِنَّآ أَنزَلۡنَـٰهُ فِى لَيۡلَةِ ٱلۡقَدۡرِ (١)
We have indeed revealed this (Message) in the night of Power: (1)

Surat Al Qadr Ayah 1
-
Laylatul Qadr is the night that is better than a thousand months:

لَيۡلَةُ ٱلۡقَدۡرِ خَيۡرٌ۬ مِّنۡ أَلۡفِ شَہۡرٍ۬ (٣)
The Night of Power is better than a thousand Months. (3)

Surat Al Qadr Ayah 3
The source of the above Ayahs are from Suratul Qadr/ 97
Answer: Lailatul Qadr (Arabic: لیلة القدر) also known as Shab-e-Qadr,is the Night of Destiny, Night of Power, Night of Value, the Night of Decree or Night of Measures,
It is the anniversary of the night Muslims believe the first verses of the Quran were revealed to the Islamic prophet Muhammad.
Allah says in the Holy Quran:

We have indeed revealed this (Message) in the Night of Power:
   And what will explain to thee what the night of power is?
   The Night of Power is better than a thousand months.
   Therein come down the angels and the Spirit by Allah's permission, on every errand:
   Peace!...This until the rise of dawn!
  —Sura 97 (Al-Qadr), āyāt 1-5

Therefore Allah himself puts this night better than a thousand months.
So worshipping on this night is better than if you worshipped for a thousand months (that's about 83 yrs, and 4 months)! SubhanAllah!
Thus it would be foolish to miss this Night of Power.
Also the ayah 4 means that on this night, God's decrees for the next year are brought down to the earthly plane. It is true that everything has been determined since the beginning of eternity and written down in the Preserved Tablet, but it is said that during this night, the Angels are informed of the destinies of the worshippers for the following year. It is a blessed Night. So, everything will be decreed on this Night. It is a night when fates are determined and it is a night of high standing.
Another important factor related to this night is that in it every decreed matter is conveyed as mentioned in the Holy Quran:

We sent it (Quran) down on a blessed Night. We were to warn [mankind]. Therein (in that Night) is decreed every matter of ordainment. Amran (i.e. a command or this Quran or His Decree of every matter) from Us. Verily, We are ever sending (the Messenger) (As) a Mercy from your Lord. He is the Hearing, the Knowing. Ad-Dukhaan 44: 3-6

Hope that answers your Questiion.
Answer: Laylatul Qadr In Quran

Verily! We have sent it (this Quran) down in the night of Al-Qadr , And what will make you know what the night of Al-Qadr (Decree) is? The night of Al-Qadr is better than a thousand months. Therein descend the angels and the Ruh by Allahs Permission with all Decrees, Peace! (All that night, there is Peace and Goodness from Allah to His believing slaves) until the appearance of dawn.

[Al-Qadr 97:1-5]

The night of Al-Qadr is better than a thousand months

[Al-Qadr 97:3]
When is Laylatul Qadr?

Narrated by Aishah (رضي الله عنها) Mohammed (صلى الله عليه و آله وسلم) says,
  Search for the Night of Qadr in the odd nights of the last ten days of Ramadaan.

[Bukhari 3:32:234]
Source: Small Khadem

What is the significance Laylatul Qadr?


Streaming low-latency video from a low-spec Linux box?

Question: For a robotics project, I have a really low-spec Linux box (76MB ram, 729MHz processor, relatively good video card...yes, we're talking about a Nintendo Wii here) which I want to use to stream video from a webcam over the network. I will be connecting one client to it on LAN (with the slowest link being 100MBit ethernet). I need to have as little latency as possible for this because the video will be my only remote control feedback mechanism.
The computer which I will be viewing the stream on is a crappy laptop with an "integrated graphics" card, so I need something relatively lightweight.
The webcam can film in up to 1280x1024, bonus points for transmitting at that resolution.
I need some command line software which can read from the webcam and stream the video in a lightweight manner which can preferably be read by mplayer. Bonus points for toggleable audio or HD screenshots on demand.
Answer: Have a look at VideoLAN, especially the "VideoLAN streaming solution" chapter in the FAQ
Comment: Good, except that it gives "Invalid Instruction" when run on the wii, and building from source is not possible due to missing dependencies in Lenny's package management system.


Why would a car company lend me money at a very low interest rate?

Question: Why would a car company lend me money at 1-2% when they could lend it to the federal government at ~2.9% with zero risk?
Comment: 2.9% Where did you see it?
Answer: Because the federal government won't use the money to buy a car thus generating profits for the car company.
The aim of cheap loans is to drive sales of cars. The difference between the amount of interest paid on the loan, and the amount they could have got by investing it elsewhere, is simply a reduction in the profit.
This is true whatever the actual interest rates are.
Answer: This is "incentive financing". Simply put, the car company isn't in the business of making money by buying government bonds. They're in the business of making money by selling cars.
If you are "qualified" from a credit standpoint, and want to buy a $20k car on any given Sunday, you'll typically be offered a loan of between 6% and 9%. Let's say this loan is for three years and you can offer $4000 down payment and/or trade. The required monthly payment on the remaining $16k at the high end of 9% is $508.80, which over 3 years means you'll pay $2,316.64 in interest. Now, that may sound like a good chunk of change, and for the ordinary individual, it is, possibly enough that you decide not to buy today.
Now, let's say, all other things being equal, that the company is offering 0.9% incentive financing. Same price, same down payment, same loan term. Your payments over 3 years decrease to $450.64, and over the same loan term you would only pay $222.97 in interest. You save over $2,093.67 in interest over three years, which for you is again a decent chunk of change. Theoretically, the car company's losing that same $2,093.67 in interest by offering this deal, and depending on how it's getting the money it lends you (most financial companies are middlemen, getting money from bond-buying investors who expect a rate of return), that could be a real loss and not just opportunity cost.
But, that incentive got you to walk in their door, and not their competitor's. It helped convince you to buy the $20,000 car. The gross margin on that car (price minus direct costs) is typically 20% for the dealer, plus another 20% for the manufacturer, so by giving up the $2,000 on the financing side, the dealer and manufacturer just earned themselves 4 times that much. On top of that, by buying that car, you're committing to buy the parts for the car, a side business with even higher margins, of which the car company gets a pretty big chunk. You may even be required to use dealer service while the car's under warranty in order to keep the warranty valid, another cha-ching. When you get right down to it, the loss from the incentive financing is drowned in the gross profits they make from selling the car to you.
Now, in reality, it's a fine balance. The percentages I mentioned are gross margins (EBITDASG&A - Earnings Before Interest, Taxes, Depreciation, Amortization, Sales, General and Administrative costs; basically, just revenue minus direct cost of goods sold). Add in all these side costs and you get a net margin of only about 3.5% of revenue, so your $20k car purchase may only make the car company's stakeholders $700 on the sale, plus slightly higher net margins on parts and service over the life of the car. Because incentive financing is typically only offered through the company's own financing subsidiary, the loss isn't in the form of a cost paid, but simply a revenue not realized, but it can still move a car company from net positive to net negative earnings if the program is too successful. This is why not everyone does it, and not all at the same time; if you're selling enough cars without it, why give away money?
Typically, these incentives are offered for two reasons; to clear out old cars or excess inventory, or to maintain ground against a competitor's stronger sales numbers. Keeping cars on a lot ready to sell is expensive, and so is not having your brand driving around on the street turning heads and imprinting their name on the minds of potential customers.
Answer: Here I thought I would not ever answer a question on this site and boom first ten minutes.  First and foremost I am in the automotive industry, specifically one of our core competencies is finance department management consulting and the sales process both for the sale of the care as well  as  the financial transaction.
First and foremost new vehicle gross profits are nowhere near 20% for the dealership.  In an entry level vehicle like say a Toyota Corolla there is only a  few hundreds of dollars in markup from invoice to M.S.R.P.  There is also something called holdback that dealers get for achieving certain goals such as sales volume. These are usually pretty easy to hit. As a matter of fact I have never heard of a dealer not getting the hold back on a deal.  This hold back is there to cover overhead for the car, the cost of getting it ready to sell, having a lot to park it on, making it ready for delivery, offset some of the cost of sales labor  etc.  Most dealerships consider the holdback portion of the invoice to not be part of the deal when it comes to  negotiations.  Certain brands such as KIA and Chrysler have something called "Dealer Cash" these payouts are usually stair stepped according to volume and vary by dealer, location, past history, how the guys at the factory feel that day and any number of combinations.  Then there is CSI or Customer Service Index payments, these payments are usually made every 1/4 are on the Parts Statement not the Sales Doc and while they effect the dealers bottom line they almost never affect the sales managers or sales persons payroll so they are not considered a part of the cost of the car.  They are however extremely important to  the dealer and this is  why after you have your new car they want you to bring in your survey for a free oil change or something.  IF you are going to give a bad survey they want to throw it away and not send it in, if you are going to give a good survey they want to  make sure you fill it out correctly.  This is because lets say they ask you on a scale of 1-10 how was your sales person and you put a 9 that is a failing score. Dumb I know but that is how every factory CSI score system I have seen worked.  According to NADA the average New Vehicle gross profit including hold back and dealer cash is around $1000.00.  No where near 20%.  Dealerships would love it if they made 20% on your new F250 Supercrew Diesel at around $50,000.00.  One last thing there is something on the invoice called Wholesale Finance Reserve.  This is the amount of money the factory forwards to the Dealership to offset the cost of financing vehicle on the floor plan so they can have it for you to look at before you buy.  This is usually equal to around 3 months of interest and while you might buy a vehicle that has been on the lot for 2 days they have plenty that have been there much longer so this equals out in a fair to middling run store. General Managers that know what they are doing can make this really pad their net profit to statement.
On to incentives, there are basically 3 kinds.  Cash to customer in the form of rebates, Dealer Cash in the form of incentives to dealerships based on volume or the undesirability of a vehicle, and incentive rates or Subvented leases.  The rates are pretty self explanatory as they advertised as such (example 0% for 60 Months).  Subvented Leased are harder to figure out and usually not disclosed as they are hard to explain and also a source of increased profit.  Subvented leases are usually powered by lower cost of money called a money factor (think of it as an interest rate) that is discounted from the lease company or a subsidized residual.  Subsidized residuals are virtually verboten on domestic vehicles due to their poor resell values.  A subsidized residual works like this, you buy a Toyota Camry and the ALG (automotive lease guide) says it has a residual at 36 months of 48%.  Well Toyota Motor Credit says we will give you a subvented residual of 60% basically subsidizing a 2% increase in residual.  Since they do not expect to be able to sell the car at auction for that amount they have to set aside the 2% as a future expense.  What does this mean to you, it means a lower payment.  Also a good rule of thumb if you are told a money factor by your salesperson to figure out what the interest rate is just multiply it by 2400.  So if a money factor is give of .00345 you know your actual interest rate is a little bit lower than 8.28% (illustration purposes only money factors are much lower than that right now).
So how does this save you money well a lease is basically calculated by multiplying the MSRP by the residual and then subtracting that amount from the "Capitalized Cost" which is the Price paid for the car - trade in + payoff + TT&L-Rebate-Down Payment.  That is the depreciation.  Then you divide that number by the term of the loan and you have the depreciation amount.  So if you have 20K CC and 10K R your D = 10K / 36 = 277 monthly payment.  For the rest of the monthly payment you add (I think been a long time since I did this with out a computer) the Residual plus the CC for $30,000 * MF of .00345 = 107 for a total payment of 404 ish.  This is not completely accurate but you can use it to  make sure a salesperson/finance person is not trying to do one thing and  say another as so often happens on leases.
0% how the  heck do  they make money at that, well its simple.  First in 2008 the Fed made all the "Captive" lenders into actual banks instead of whatever they were before.  So now they have access to the Fed's discounting window which with today's monetary policies make it almost free money.  In the past these lenders had to go through all kinds of hoops to raise funds and  securitize loans even for super prime credit.  Those days are essentially over.  Now they get their short term money just like Bank of America does.  Eventually they still bundle these loans and sell them.  So in the short term YOU pay for the 0% by giving up part or all of your rebate.  This is really important DO NOT GIVE up your rebate for 0% unless it makes sense to do so.  When you can get the money at 2.5% and get a $7000.00 rebate (customer cash) on that F250 or 0% take the cash.  First of all make the finance guy/gal show you the the difference in total cost they can do do this using the federal truth in lending disclosures on a finance contract.  Secondly how long will you keep the vehicle?  If you come out ahead by say $1500 by taking the lower rate but you usually trade out every three years this is not going to work.  Also and this is important if you are involved in a situation with a total loss like a stolen car or even worse a bad wreck before the breakeven point you lose that price break.  Finally on judging what is right for you, just know that future value of the vehicle on for resell or trade-in will take into effect all of these past rebates and value the car accordingly.  So if a vehicle depreciates 20% a year for the first 3 years the starting point will essentially be $7000.00 less than you actually paid,  using rough numbers.
How does this help the dealers and car companies?  Well while a dealer struggles to make money on new cars the factory makes all of their money on the  new cars and the new car financing.  While your individual loan might lose money that money is offset by the loss of rebate and I think Ford does actually pay Ford Motor Credit Company the difference in the rate.  The most important thing is what happens later FMCC now has 2500 loans with people with perfect credit.  They can now use those loans to bundle with people with not so perfect credit that they financed at 12%-18% and buy that money with interest rates in the 2%-3% range.  Well that is a hell of a lot of profit.  'How does it help the dealership, well the more super prime credit they have in their portfolio the more subprime credit the banks will buy for them.  This means they have more loans originated that are more profitable for them.  Say you come in for the 0% but have 590 credit score, they get FMCC to buy the deal because they have a good portfolio and you win because the dealer gets to buy the money at say 9% and sell it to you at say 12% making the spread.  You win there because you actually qualified for a rate of around 18% with a subprime company like Santander or Capital One (yes that capital one) so  you save a ton on your overall cost of the car.
Any dealership that is half way well run makes as much or money in the finance and insurance office than the rest of the dealership.  When you factor in what a good F&I Director can do to get deals done with favorable terms that really goes up.  Think about that the guys sitting a desk drinking coffee making more than the  service department guys all put together.
Well that was long winded but there I broke down the car business for whoever read this far.
Answer: In addition to the other answers, also consider this: Federal bond interest rates are nowhere near the rates you mentioned for short term bonds. They are less than 1% unless you're talking about terms of 5-10 years, and the rates you mentioned are for 10 to 30-years terms.
Dealer financed car loans are usually 2-5 years (the shorter the term - the lower the rate). In addition, as said by others, you pay more than just the interest if you take a car loan from the dealer directly. But your question is also valid for banks.
Answer: They aren't actually. It appears to be a low interest rate, but it doesn't cover their true cost of capital.
It is a sales tactic where they are raising the sticker price/principal of the car, which is subsidizing the true cost of the loan, likely 4% or higher. It would be hard to believe that the true cost of a car loan would be less than for a mortgage, as with a mortgage the bank can reclaim an asset that tends to rise in value, compared to a used car, which will have fallen in value.
This is one reason why you can generally get a better price with cash, because there is a margin built in, in addition to the fact that with cash they get all their profit today versus a discount of future cash flows from a loan by dealing with a bank or other lending company.
So if you could see the entire transaction from the "inside", the car company would not actually be making money. The government rate is also so low that it often barely covers inflation, much less operating costs and profit.
This is why any time you see "0% Financing!", it is generally a sales tactic designed to get your attention. A company cannot actually acquire capital at 0% to lend to you at 0%, because even if the nominal interest rate were 0%, there is an opportunity cost, as you have observed. A portion of the sticker price is covering the real cost, and subsidizing the monthly payment.
Answer: The car company loans you money at 1 or 2% because it is part of the incentive to get you to buy the car.
Car company transactions are complex involving the manufacturer, the dealership, and the financing part of the car company. Not to mention Rebates, the used car transaction, and the leasing department. If they don't offer you a loan then the profit from that part of transaction is lost to an outside company.
The better loan rates from the manufacturer are only with shorter term loans and without the rebate. That is why some suggest that you get the rebate, and then go to a credit union for the loan for lowest overall cost and greatest flexibility.
The advertised rates are also only for the customers with great credit scores and the room in their clash flow to pay off the loan in a year or two. If you don't fit in that category, the rates will be higher.
Answer: I agree with @mhoran_psprep 1-2% is ploy dealers use to get people to buy the cars, it's a good deal if you take advantage of your good fortune.
It's a good deal if your credit score is excellent you can get it and if you pay on time you won't have to pay any fee. The only trick is that if you don't pay on time there's a stated percentage compounded from day 1. It's a selling tactic and not everyone will qualify for 0% interest for the simple reason that the term is usually 36 months or less and not everyone has room in their budget for a large payment. That then moves to different rates and different terms.
Here's my advice
When making payments pay a little more than what the monthly payment is which will get the remaining principal down to something much less, so interest will be lower.
Comment: Or simpler yet, compare the price of the car with the loan, versus what they'd sell it for if you walked in with a stack of $100 bills :-)


Preventing axis being messed up by adding new objects to the scene in Front Perspective View

Question: I've already had question according array modifier. I had changed object alignment from 'Align To: World' to 'Align To: View' in the 'User Preferences'. It's because i wanted to add objects in 'Front Persp' and spare me rotation steps i every time take when i'm adding a new object. After changing it i ended up having problems with modifiers relative offset properties, i had to tweak the 'Y' axis to move it up and 'Z' axis property to move it in the direction where normally 'Y' axis would be. So the question is: is it possible to add objects in 'front ortho' without messing up the axis of the object?
Answer: No, you either get it aligned to your current view, including the object's local orientation, or globally oriented.
Apply object rotation
Go to Object Mode and press Ctrl+A, 2 (Apply Rotation) and your object orientation is applied, meaning that the mesh stays exactly the same but all 3 axes are parallel to the global ones afterwards.
Concerning default behaviour
You can't make blender apply the rotation of your object all the time or always when you add an object.
I guess it would be possible to write a python addon/macro to always realign the axes for you after adding an object, but someone else would have to help you with that.
Other workaround
You can add any object first from top view (Numpad 7), delete the mesh (X) and re-add the mesh you want from the perspective you want (e.g. front with Numpad 1, Shift+A). This will only add the mesh within the already correctly aligned object. Which is not really a lot faster than the method mentioned above, sadly.
Third (probably best) workaround
Go to top view (Numpad 7), add the object, go to front view (Numpad 1), press F6, (disable and)* re-enable "align to view", this re-aligns the mesh to the current view without altering the object orientation.

only if align to view is enabled by default
Comment: It basically rotates the objects to be aligned to the global coordinates, and then rotates the mesh back to where it was before from a global point of view, so both the orientation of the object and the position of every point within the object change, but globally, the mesh stays where it was.
--
See also: http://wiki.blender.org/index.php/User:Fade/Doc:2.6/Manual/3D_interaction/Transform_Control/Reset_Object_Transformations
 --
I added a comment on the default possibilites above, but there is no ideal solution.
Comment: Great!! it does work but could short explain why? Did i just rotated objects orientation to have it aligned with global orientation? because the object itself does seem to stay untouched.
Comment: and is it possible to set it as default behavior?
Comment: I added a third workaround that's probably even better, partially based on sambler's answer.
Answer: The option to align to view or world is available to each object added. Pressing F6 after adding an object gives you the operator options, which is also visible at the bottom of the tool palette by default. Among the options you have for a newly added object is Align to view, if turned off it is aligned to world.


Is watching cartoons/anime for entertainment Haram?

Question: If it is Haram, as long as I don't believe what they include or say, am I committing shirk or am I going to get punished like the sketchers of the series?
Answer: First of all i would say what counts in any matter is the intention.
Then when it comes to drawings and pictures etc. i think our dear brother @American-Muslim gave you a few helpful links and an answer, but i'd like to explain my Point of View:
My opinion is that one must take some facts in account for example still when our Messenger died there were many pagan's in the Arabic peninsula and there are still many in some of the "Muslim Countries" nowadays. But the most relevant fact to me is that our Messenger (peace be upon him) forbade them because many people just converted to Islam and rejected their idols (after a long time worshiping them) so there was a more or less slight chance that they have a fall-back to their former Idolatry. So forbidding them -in this case- makes sense!
But today you'll find even in many Muslim countries some (more or less modern) Statues but nobody even thinks of worshiping them, even if in some cases this statues and placing them in some Public places etc. and admiring the Person it represents could be regarded at least as something near to worshiping!
Finally i come to cartoons:
First watching TV and anything which could be regarded as a waste of time has -if we take it very severely and exact- always a touch of makroh. But we shouldn't forget that we are not angels and we need to relieve stress from time to time, so watching TV etc. could be a way to do so. So i can't see any harm in this unless what you are watching is somehow against the rules of Islam or regarded as a sinful act in that case at least you will do a sin!
Now as you said you don't believe in what you watch and i personally can't see any link to shirk in Cartoons (in general), i can't imagine why that should even lead to shirk or that you'll be punished for watching. But you still have to be aware that whether the act of watching would be considered as sinful or not depends on what you are watching and on your intention and true belief and how you interact/react with/on that (see also this Hadith which has some relevance)!
So as a conclusion I'd give you the same advise mentioned by @American-Muslim if you believe that an act would be sinful you should stay away and turn away from it!
And here are some more or less related fatwas 1 2 in English and one in Arabic/Turkish for some more details and a more sever (salafi) Point of View.
And Allah knows best!
Comment: One of the terms would be that no religious discrimination would be allowed. Also not to mention that I only use IslamQA if there is no other site which would give me a proper answer.
Comment: @HüdaverdiAlperenDemirok well islamQA is one of the rare sites that provide fatwa in English that's why i do refer to it, as many people here don't know Arabic and the official language of this site is English!
Answer:
Is watching cartoons/anime for entertainment Haram?

In my opinion it is not Haram. The prophet forbade drawings (of people), however Anime characters are usually unrealistic in origin. There are other reasons as well if you are interested check the following questions.

If it is Haram, as long as I don't believe what they include or say, am I committing shirk or am I going to get punished like the sketchers of the series?

If you believe something to be Haram, then doing it is a sin which Allah might punish you or given you. That isn't something a person can know. The best thing is to stay away from things you believe is Haram and ask Allah for forgiveness.
Comment: Citations needed. Your opinions doesn't matter. And anime characters are usually very realistic
Comment: You think very differently from other higher-ranking people from this site, or internet in general. You seem to have views that are more suitable for today's life.
Answer: It is not haram, but watching inappropriate animes with girls in swimsuits and big breasts- even if it's unrealistic, is haram for all genders.
Answer: Assalamualaikum. I do not know about cartoons and such but i used to watch alot of anime a few months ago and i recommend based on this that u should not get yourself into anime. Trust me. Even anime which seem to be for a younger audience turns out to have sexual content i have some examples but i do not want to share them as i dont want people to start googling these.So, even if animations are halal(to which i do not know the rulings of scholars),i would recommend that u stay away from anime and i think that the rest of the questions have been answered by others above (maybe lol). In the end Allah knows best.
Answer: in my opinion, something is haram if it takes you away from ALLAH(STW). if you are missing your salah's by watching anime, then it is clearly haram or if you are watching certain categories of anime like: hentai,harem or ecchi is haram coz it will lead you to doing something which is clearly haram and sinful. there are other types of anime like shonen and shojo. shonen anime are based on adventure, fighting,comedy etc. shojo on the other hand focus on romantic and funny anime. shojo might take you to commiting a sin, so just be carefull, there is a small chance. both the anime have beautiful anime girls, and you are not drawing these so you should be fine.
shonen example: one piece, dragon ball franchise, naruto, AOT.
Shojo example: Kaichou wa Maid-sama, Tonari no Kaibutsu-kun, Kimi ni Todoke.
There are also family friendly anime like: doraemon, shinchan, ninja hattori etc
Answer: I DON'T HAVE A DIRECT ANSWER FOR THIS, BUT I DO KNOW THAT IT IS HARAM to draw anything that is depicted as living (having a soul). It is honestly hard to find an answer to this question, as there are many different opinions
Answer: ikeepmynamehidden, I have a question. So, I watch Naruto right and it has chakra and powers which comes from Buddhism, but I ignore that and just pay attention to the plot and just think that chakra and all those powers are just for entertainment. They use the chakra and powers to do jutsus such as shadow clone jutsus,etc. When I watch naruto, it kinda helps me in Islam because it is about never giving up and the soundtracks are inspiring, so it is still haram to watch naruto
Answer: Assalam o Allaikum.
First of all, let me tell you I do not know whether this is Haram or not. But I surely do know that this can not be considered as 'Shirk'. Because shirk as is the act with means to worship someone else other than 'Allah' or to include any other being in worship along with 'Allah'.
Answer: hlo i am probably late .but still. when u come to the talk of anime .anime's that categories to ecchi,harem,hentai are all haram coz they are related to sexual thing .before u watch an anime check the genres and try to get info on that genres . .the others like pokemon and doraemon are not haram
Answer: Statues are haram -> referring to Medi1Saif's answer. And regarding haram, intention is not of importance. You cannot do something haram like drinking alcohol and say "I have a good intention".
Regarding watching cartoons: It is not unproblematic: Music and drawing are problematic, the story is important and it must not lead you to something haram or it must not contain something haram.
Answer: I've wondered this for a while, about Naruto, when they present themselves in god like ways. Also involved are alot of Buddhist ideologies, and sometimes unconsciously you might say the names of their goddesses or gods... I don't know the correct answer, but I think it's best to keep a certain limit. The intention is what really matters, if you're watching it because you find it interesting and fun, then you must regard it as it is, don't get too involved or obsessed with it. I like to watch stuff at night, after I'm done with everything.
Again, I grew up in a Muslim country and that show was literally my childhood, everyone, from adults to kids watched it. Even really good Muslims I know, watch it. So it's best to say, not to get too involved in it. It's just a show made from someone's imagination, so be it that way. And if you feel uncertain, talk to a close one.
Hope this helped.


Two External Drives on iMac

Question: Can I use the Keyboard USB Port for a second External Drive on my iMac? I've seen warnings to not use the keyboard port for external drives, but no explanation. How do I use 2 external drives, if not using keyboard port?
Answer: Some USB drives (typically the smaller, more portable sizes that use 2.5" hard drives) draw their power over USB (called bus-powered). Others (typically the larger 3.5" ones) have an external power adapter.
If you have one with an external adapter, you should be fine plugging it in to whichever USB port you want. Bus-powered ones plugged into a USB hub (like that in your keyboard) with other devices may not have enough power to start up, or they may start up, but the connection will occasionally drop (you'll see the drive disappear from your desktop). However it's safe to at least try plugging it in to your keyboard and see if it works. If the drive doesn't show up, try directly connecting it to a port on the back of your iMac.
Ideally you'll plug both hard drives in to the USB ports on the back of your iMac (every iMac since 2006 has at least 3, sometimes 4), which ensures maximum power and bandwidth. If you're short on ports, you can also get a standalone USB hub, which you could plug your lower-powered devices into, in order to free up ports for your drives.
Comment: I forgot about bus power, the best reason to not use the keyboard hub.
Answer: You may be able to, but it's probably not a good idea. Some keyboards with USB hubs (including older Apple keyboards) have hubs that only support USB 1.1 - any drive plugged in there will be very slow. Also, having the drive connected to a user-interface item (the keyboard) will make it easier to accidentally disconnect.
All iMacs I've ever used have had far more USB ports than I could possibly use. Are you sure there's not an extra unused port on the back? Can either of your drives be connected via FireWire or Thunderbolt instead of USB?

Two External Drives on iMac


Could it be possible for man to create a star?

Question: If it were possible for us to create a star or a new sun, how could it be done, or how would it have to be done?
Comment: This is a worldbuilding question asking us to speculate about fictional (and vague) capabilities that aren't obviously a part of science.
Comment: You start with a big bang; then wait half a billion years or so...
Comment: Why would you? There are 200 billions in the Milky Way, and you want _more_?
Comment: You have to tow planets/gases .. etc. (or any kind of matter) and keep dumping at one place where you want the star to be. For example you can start dumping stuff into jupiter. You keep dumping until it becomes a star. good luck!
Comment: [There is one under construction in France](https://www.iter.org/mach)
Comment: @Count Iblis Here's another one that's being turned on right now: https://en.wikipedia.org/wiki/Wendelstein_7-X
Comment: Step 1: Locate hydrogen source
Comment: NB: Chris White is pointing to [worldbuilding.se] where questions of this nature are answered with a (pseudo)sciencey response.
Comment: Yes, I am a fiction writer fascinated by astrophysics, though I usually stay away from it in my writing. Chris White, Kyle Kanos, thanks for pointing me to the worldbuilding.
Answer: Answering a question like this requires a shift in thinking from normal physics & engineering to something akin to the futuristic thinking accompanying the concept of a Dyson Sphere: https://en.wikipedia.org/wiki/Dyson_sphere  With this in mind it seems that the only possibility for humankind to "create" a star in the foreseeable future would be through the "butterfly" effect.  By that I mean introducing a small perturbation into a distant cloud of gas and dust that could get magnified by extreme sensitivity to initial conditions so that the resulting "storm" would be the formation of a new star.  The perturbation could be delivered by a small space probe sent into an appropriately chosen cloud of gas in our galaxy: a cloud that already possessed the potential for star formation.  Do we know how to do it now? No.  Could we learn by intensive study? Yes.  The possibility for funding such a project might improve in a few billion years as the red giant phase of our sun draws near (if man kind's propensity for science continues).
So what are the conditions required for the butterfly effect to manifest itself.  The first requirement is a nonlinear system.  The second is that the system exhibit dissipation (friction or viscosity).  For fluid systems described by the Navier Stokes equations, both of these conditions are present. A final requirement is that the system be subject to periodic or aperiodic driving forces.  Two gas clouds in orbit about each other and deforming via tidal forces fulfills this last requirement.
The ALMA observatory has recently produced a striking image of star formation in just such a scenario: http://www.almaobservatory.org/press-room/press-releases/723-dynamical-star-forming-gas-interaction-witnessed-by-alma-  Following this link one see a newly formed star (a protostar) between two gas clouds.  Below the astronomical image is a computer simulation of the dynamic interaction for two such fluids. In the region of overlap between the fluids the excessively turbulent rotating flow greatly resembles a hurricane or tornado.  The implication is that such "stormy" conditions are indeed the cradles of star formation.  This casts doubt upon previous views of star formation that supposed the process to proceed slowly via gravitational contraction of gently moving gas clouds.  These stormy situations are where the colorful "butterfly effect" terminology originated.
So what are the possible "butterflies" that man kind could use to influence such a potentially star forming region and how could we ever know that we were in fact responsible for birthing a new star?  Suppose we found a situation where the two gas clouds were just beginning to overlap and we were able to arrange for our probe to arrive on the scene (slowing down to just the right speed) at just this moment.  We might "seed" turbulence into the clouds by releasing atomic oxygen from our rapidly spinning probe. The oxygen would react with hydrogen already present in the cloud to form a small vortex of water molecules and the nonlinear dynamics of storm formation could take it from there.
A much more likely scenario (although still exceedingly difficult with today's technology) would be for us to arrange for a probe to arrive after some turbulent motion had begun but before significant gravitational nucleation had started.  This time our probe could release a strongly magnetized hunk of iron and seed the accretion process as iron dust (already present in the cloud from previous supernovas in the vicinity) was attracted.  This magnetic attraction could significantly jump start the nucleation process since the electromagnetic force is many orders of magnitude stronger than the gravitational attraction.
The question of "how would we ever know" that we were responsible is much more difficult to answer.  Stars are formed all the time, after all, without our assistance.  The answer to that will have to come from future advances in our understanding of nonlinear dynamics perhaps learned from interactions with a civilization that already inhabits a Dyson Sphere.
Comment: The butterfly effect only works on dissipative systems that are driven by an energy source. It doesn't work on conservative systems. While there is a little bit of dissipation in the solar system, even today, it's not enough anymore to do what you have in mind (otherwise a new star and planets would be forming anyway).
Comment: You don't need a trigger for that. Gas clouds have been forming stars since the beginning of the universe. If anything, we lack the theoretical explanation of how they did it as fast as they did, but there is certainly no need to give them a hand. :-)
Comment: @CuriousOne suggest you delete your comments if you agree my edit adequately represents them.
Comment: Hey guys, (Lewis and @CuriousOne) why don't you add a summary of your conversation in Lewis's answer? You both make some points that are very interesting and relevant.
Comment: @WetSavannaAnimalakaRodVance Have taken your suggestion. Will delete my comments.
Answer: Step 1: Locate hydrogen source.
Step 2: Create a massive shock wave which will compress the gas in some parts and rarefy it in others. This gives you a mass gradient.
Step 3: Wait.
Step 4: Hopefully in a few million years time, the concentration of hydrogen is critical enough that it starts to sustain thermonuclear reactions.
Answer: There is no way to "ignite" a gas giant: even if you could temporarily start fusion in it's core, any artificially-generated reaction like this would be self-limiting: the energy it creates causes the proto-star to expand a little bit, and then nothing else happens.
If we had infinite time, we could always create a star by just collecting an absurd amount of matter and bringing it all to the same place, but it's hard to imagine this ever being a worthwhile endeavor.
Comment: The old Usenet joke had you collecting the only infinite mass supply in the universe: AOL disks.
Answer: This is my guess but seems possible. If there was very cold gas giant (few times grater than Jupiter) than one could try to "ignite" it - start nuclear fusion. It has to be very cold so that reaction would not be started automatically. The idea is to drop a bomb (hydrogen for example) to the core of the planet. Bomb has to withstand extreme preasure while falling into the core but shield has to be weak enough to break due to presure from the inside of the bomb after explosion.
Comment: *"(few times grater than Jupiter"* For values of "a few" on order of 70. Seriously, the Tzar bomb wasn't even a Christmas popper compared to Jupiter's sustained Virial heating and Jupiter nearly two orders of magnitude too small for even a trickle of fusion (which is what red dwarfs get; don't think "ignition" think "things are cramped enough that quantum mechanics allows the star to occasionally get lucky").
Comment: At the very *minimum*, you'd need it to be at least 13 Jupiter masses (generally regarded as the minimum mass of most brown dwarfs). At that point, you'd only have deuterium fusion. To create a small, dim, red dwarf, you need to multiply that by about 6. I also disagree about the temperature. Nuclear fusion via the p-p chain can start at ~ 10$^7$ Kelvin, and planets do *not* get that hot. [Related question.](https://physics.stackexchange.com/questions/34573/turning-jupiter-into-a-star?lq=1)
Comment: I think you are right about the size of the planet. I agree about quantum mechanical effect - once a while spontaneous two particle fusion appear. The idea is to have such a preasure and temperature that two particle fusion will not start chain reaction but nuclear bomb will start. I thought about about planet temperatures where matter is in super fluid state - heat conduction is very fast.
Answer: Have you ever read Arthur C Clarke's book called "2010"
Intelligent aliens increased the mass of Jupiter until it reached a critical point and collapsed into a small star. The reason was to create a small solar system with the moons of Jupiter increasing the chance of life on Europa.