This is part of a larger series; I’d recommend that everyone read the overview first.

Ever have one of those objects around the house of completely unknown provenience? That’s my mystery filter. Did I buy it and forget? That doesn’t sound like me. Get it as a gift? …Maybe? Was it the result of an occult ritual? Could be. Will I be cursed if I get rid of it? Almost certainly.

The filter has no label on it, so I don’t know who made it. In these reviews, I call it my unknown filter or mystery filter, because I doubt the true name is known to the living. It doesn’t fit my 58mm lens, or on a 52 mm adapter, and seems to be a size between them. There is only one size between the two for modern cameras, 55 mm, but it doesn’t seem to be that either. Measuring it with calipers, it seems like one side is almost a millimetre longer than the other. Either the filter ring is warped or, despite all natural laws and common sense, it is designed to fit an oval-shaped camera lens.

… I’m going with occult ritual.

I literally can’t recommend this filter, as I have no idea what it is called or how to buy one, so  I’m using this filter as a control sample. It is that most rare of objects,  a UV filter that can actually block UV, so it is the best reference to compare other UV filters against.

Again, the seven criteria:

1- How is the packaging design(0% of total score)?

2: How is the protective case size & durability(5% of total score)?

3- Do the reflections off the glass look off-colour(5% of the total score)?

4- Does it block UV light for my full-spectrum camera(35% of total score)?

5: Does it block any light for my full spectrum camera(10% of total score)?

6: does it block any UV fluorescence  from a black light(35% of total score)?

7: How reasonable is the price(10% of the total score)?


1- Packaging: n/a out of 5.

There is no package. There was never a package. It merely Is. It Is and It always Was!


2- Protective Case: n/a out of 5.

There is no case. It is not protected. It is YOU who must be protected!


3- Reflections off the glass: 5 out of 5! Finally, a real answer!

The filter has discoloured reflections. It is usually a pink/violet colour,

2018 10 22 10;34 _MG_3509 (Medium)

…but becomes blue at certain angles.

2018 10 22 10;34 _MG_3510 (Medium)

It definitely has some type of coating, but do not ask what the coating consists of, for some things man was not meant to know.


4-  UV filtering seen through my camera: 4 out of 5.

It is very slightly darker with the short pass filter:

2018 10 22 10;33 _MG_3501 (Medium)

with a full UV camera, it is much darker.

2018 10 22 10;32 _MG_3498 (Medium)

As scared as I am of insulting The Filter, I don’t think it is as good at blocking UV light as my eyeglasses, so it loses a point.  You can faintly see through the filter, and even see some reflections in the UV range.

The filter looks dark in the above photo, but the truth is a bit more complicated. If there is is a strong light source behind it(sun, brught cloud), it is actually reflective, appearing mirrored.   When making photos for my overview, I had to reject a lot of them because I didn’t realize this was the case:

_MG_3894 (Medium).jpg

If the light isn’t as bright behind it, the filter will appear dark. I suppose it is like a one-way mirror, but only outside the visible spectrum. As it will always be dark on one side when attached to the camera, I don’t usually notice this reflection.

Side note- Because of the reflections, it might not be as clear to take photos through this as through other filters, but as it is the only camera filter I’ve tested that has a strong UV blocking effect, this is the filter to beat in my tests.


5- Blocking other wavelengths: 5 out of 5. Perfect!

2018 10 22 10;34 _MG_3505 (Medium)

It doesn’t show up well in photos, but the lens filter is very slightly darker in the visible spectrum. It looks almost like a polarized lens(to be clear, it isn’t one), except for the reflections.

In the infrared range, it isn’t opaque, but rather, like in the UV range, it is mirrored:

2018 10 22 10;39 _MG_3529 (Medium)

There is an invisible copy of me on the other side of the lens, only seen in the darkness visible, that light which man cannot see. He waits for me to look away… he waits patiently…

But until then, lets talk about the reflection again. The filter isn’t actually a UV filter, I guess. It is an UV/IR cut filter, blocking light beyond both ends of the visible spectrum. It seems perfectly mirrored from a straight-on view, but it isn’t fully blocking the IR light either. When placed against the camera lens, that is more apparent, as there is no light to reflect inside the camera. Depending on the angle of the filter, it is also apparent:

2018 10 22 10;39 _MG_3531 (Medium) The yard can faintly be seen through the lens.

6: Blocking UV Florescence: 4 out of 5.

I’m just ghost hunting now, aren’t I? I have a cursed filter, cameras to see outside the visible range, and a black light.

Fortunately, my bathroom is both dark and ghost free.

_MG_2605 (Medium)

Compared to the ‘other’ UV filters, the mystery filter(bottom right) is much darker- the UV light can’t make the paper below fluoresce, so the filter casts a shadow beneath it. Again, though, my glasses do a better job. Still, 4 out of 5.


7: Price: n/a out of 5.

You do not pay through money. Instead, go the the part of your town never spoken of, the hidden streets populated by the forsaken ones. Do not approach them; when the time is right, one will come to you. They will ask you to complete three quests, challenges which will strain the body and chill the soul. When complete, you may ask one boon; now, and only now, may you ask for the UV filter. Be sure to clarify what size you need- I sure didn’t.

Okay, I don’t know how much it cost; the above is just an estimate based on my shopping habits.



Seventy one percent and three N/As!

It might not fit on any human camera, and by using it you might lose the ability to ever again feel joy, but other than that, it tests fairly well. It gets a coveted second place!

… and hopefully that score will appease it, so I can sleep once again.