( https://sites.google.com/site/mandelbulber/getting-started#TOC-Rendering-animation ) but I was reading that this tutorial is for Mandelbulber V1 and it's different than V2.
Can you explain to me what is ( frames per keyframe)? and what is the right value for frame per keyframe if I will render the animation in 4k resolution and 30 FPS ?
there is also a section on animation with audio, but the complete topic of animation is huge and has yet to be written.
Frames per keyframe. If you are using 30 fps then it is often a good idea to make frames per keyframe multiples of 30.
At keyframes you can change the values of parameters that you have added to the keyframe animation table. So if you choose 120 frames per keyframe, then your keyframes will be at every 4 seconds (120/30) of the animation. It depends a lot on what you are trying to achieve.
When learning I would suggest try making some animations at maybe 400 x 300 resolution and keyframes at maybe 480 frames per keyframe. Also you can set animation to 15 fps, and get a quicker trial result and then when you are happy, change to 30 fps with a larger resolution for the final animation.
If you want to achieve transparent background you have to setup proper output format.
In animation dock has to be selected PNG format. Additionality you have to enable alpha channel in saved images. To do this, go to File/Program preferences. On Image tab there is Alpha checkbox. To have to tick it.