I wanted to share some info in case anyone else is having a hard time finding solutions to this problem (and okay fine, also because I'm always a little paranoid that even though it seems like the method works, I'm still doing something wrong):
We shot 2k footage in 2048x1080 on a RED Epic with the intention of ultimately cropping it into 2.35:1. We've been adding black bars on the top and bottom (I'm aware there's a Widescreen filter but we're also adding a layer of grain so I didn't want that over the black), but I didn't want the bars to exist on the final film, so I was looking for ways to crop the actual frame itself to 2.35:1 (or maybe re-size is a better word). I read in some posts on here that people were suggesting to do that in Compressor, but I wanted the film to be able to exist in true 2.35:1 on the uncompressed file.
I found this site (http://devowe.com/2-351-cinemascope-anamorphic-aspect-ratio-tutorial) which explained how to calculate aspect ratios, and realized that I could right-click on the sequence in FCP, go into Settings, and just change the frame size after finding out what the 2.35 version of my 2048x1080 frame would measure out to (all I had to change was the height, obviously, which calculated out to be 871 from the original 1080, in case anyone was curious).
I did a test export of an uncompressed QT file and it seems to have worked. So, if you were wondering about this like me, hopefully this helps clear things up.
(But if any of the big guns on here think I'm totally wrong to do this, please let me know)
I always come on here to get answers, so hopefully this me being able to give one for a change.
i'd say wait till you're done editing till you do this, as you wont get any RT with a non-standadrd sequence size.
and if you render as you go, it; would be pretty simple to export it as-is,
and then run that through compressor, using it;s cropping function in the Geometry tab.
it;s simple, and probably faster than FCP.
you dot have to drop the quality at all, just use a Prores codec, even the same one you've been cutting with.
i'd also say that "2.35" is not a common ratio these days, even though it's a common TERM.
the ratio we've been delivering lately is 2.40:1
also, who or what are you making this for?
find out what you actually need to deliver.