[SeeMoreDigital]

Originally Posted by bkman

So that is the question that I haven't seen everyone agree upon: If you have a movie/show that you "know" the aspect ratio of (16:9, 4:3, etc) but it has black bars which need to be cropped, do you a.) Use the cropped size in your SAR calculation, or b.) Use the original size before cropping?

What I do is establish the aspect ratio of the source movie. The popular "Movie Aspect Ratio's" (MAR's) are, 1.85:1, 2.35:1, 2.40:1

All MAR's can be converted to a fraction. For example: -
1.85:1 works out at 37/20
2.35:1 works out at 47/20
2.40:1 works out at 12/5

The MAR value can then be placed into the equation like this: -

MAR    FAR                              ARS 
47     368     17296                    1081
--  x  ---  =  -----  lowest dominator  ----  Giving an ARS value of 1081:900
20     720     14400                     900

Which can be further simplyfied by converting: -

1081      1080                    6
----  to  ----  lowest dominator  -  Giving an ARS value of 6:5
 900       900                    5

Cheers