Hi,
Anamorphic lenses are how you get widescreen in the cinema.
The lens works with cinema projectors on film footage already taken to allow for the increase in width compared to height the lens produces so that footage is shrunk one way to get normal again when it's gone through the anamorphic lens.
It's like watching a widescreen movie on a normal shape TV without any modifications.
. Everything is squashed sideways so people are long and thin and cars look too short.
a or ana = not
morph = shape
anamorphic = not the same shape
The usual set-up is a 2:1 widening of the frame and 1:1 in height, or the new standard of 16:9 from a 16mm or 35mm cinema film.
A lens having different magnifying powers in different directions, including the eye, is called astigmatic. They have astigmatism.
The lenses with the same image scale in all directions, showing no astigmatism which can turn dots into lines, are called ana-stigmats...anastigmats.
With that anamorphic lens the images from them will be projected too wide so cars get very long and people get very fat.
You'll have seen that word many times on lenses from way back, but all normal lenses of decent quality are now anastigmatic. We take it for granted now.
http://www.cdegroot.com/photo/images/kodak_anastigmat.jpg
http://farm4.static.flickr.com/3119/3186007862_a531d03b6a.jpg
You'll see a squashed guy on the right, scroll down. The anamorphic lens projects that squashed image and shows it corrected on the big screen so it looks normal. The whole frame gets the same treatment so it turns out very wide and then you see Widescreen.
The original frame was taken with an anamorphic lens that did the squashing and then another one unsquashed it but the shape of the frame itself wasn't squashed so it turns out much wider, producing the magic Widescreen image with normal shaped people and cars.
http://owyheesound.com/anamorphic.php
http://documentation.apple.com/en/finalcutpro/usermanual/chapter_F_section_8.html
16mm and 35mm professional (in the real sense) cinema projectors tend to have standard fittings in nearly all countries..
Only a few have odd ones.
I did a cinema projectionist course as part of my instructor job to show training films in the Army and helped out at times in the local cinema when they were stuck and still do ...part time but you get to see free movies and get paid for it, haha.