ByT EdU

A quick ByT EdU. Deals with a few of the common conventions we ByT'ers deal with.

Anamorphic Lens
     Basically take an image that is squished and use 2 prisms to un-squish the image. Lets take a step back. Why is the image squished? Not due to equipment error, but done on purpose! The projectionist takes a 16:9 ratio movie, tells the projector to use all pixels in the Y direction that it can display at the cost of the X direction. So the image is stretched up and down to use all the pixels the projector can display in that direction. It also keeps the ratio locked so you will end up with black side-bars on the left and right of the movie. Watching this on a screen, you will see a squished (up and down) image. You then slide in the Anamorphic Lens system you've either built or bought (both ways are on the expensive side), and voila! The image is un-squished in the X direction. Thusly the ultra-wide CinemaScope screen should be nicely filled in without displaying any black bars in either direction!

Aspect Ratio
     A long drawn out explaination of various ratios can be found here at Wikipedia http://en.wikipedia.org/wiki/Aspect_ratio_(image) . Lets make it simple. There are a few major ratios used these days but all of cinema history includes various sizes. The most commonly used sizes are 4:3, 16:9, and 2.35:1.

4:3 ratio was the standard ratio for early television. This closely matched early cinema (which wasnt 4:3 but very close). Attendance in theaters dropped as television was adopted by more and more households. So cinema adopted the 16:9 format to differentiate itself.

4:3 "Indian Head" test pattern

16:9 ratio or "Widescreen" is used for the ratio used in cinemas from around the middle '50's up until now its still common. Again widescreen tvs began to roll out and cinema wanted to differentiate itself, so cinema went to 2.35:1 aka CinemaScope.

16:9 "Indian Head" test pattern

2.35:1 "CinemaScope" ratio. Most modern feature films are shot on this ratio. basically take the 16:9 ratio and stretch it out a lot more. There are hardcore movie enthusiasts who have stopped at nothing to get this ratio. "As the Director intended" is a common battle-cry. Current movie delivery standards, worlds above VHS and DVD, still cannot handle a properly sized CinemaScope ratio movie. These same enthusiasts have developed ways to better mimic CinemaScope ratios at home. More info can be found under Anamorphic Lenses.

The next logical step is to wrap a display around your head

Constant Image Height