I've been reading a bit about anamorphic lenses and how they work, but I'm curious about a few things:
1. Are anamorphic lenses essentially designed to have specific, controlled astigmatism, where one meridian of the lens has a different focal length than the other? What's the difference between a lens with astigmatism and an anamorphic lens?
2. Related to the first question, if anamorphic lenses have two different focal lengths, how is it that the squeezed image projected onto the film is completely in focus? The affect of having two different focal lengths should mean that only one meridian would be in focus at a time, right?
3. When using a motion picture camera using anamorphic lenses, does the viewfinder have to be changed every time a different lens is placed on the camera? If not, then how is it that one single viewfinder can correctly decompress the image projected from different anamorphic lenses?
4. I've noticed that the characteristic anamorphic flare is always blue. I assume this is due to the antireflection coatings, but lens flare in spherical lenses can have different colors depending on the particular coatings used on different lenses. So does that mean anamorphic lenses all use the same AR coatings? If not, then why is the flare always or almost always blue?
Thank you so much. I'm a student who has, as yet, never used a motion picture film camera or anamorphic lenses, but I'd like to someday and so I want to learn about them and how they work.