Letterbox – fcp and compressor – different results

[Josh Olenslager]

Hi Joseph,

You might make sure that you have the exact ratio you want selected in your compressor output as it has various options including: European standard, traditional 16.9, scope, etc. Personally, I would continue your output process using compressor. I’ve had much better and more consistent results. Also, if you’re using the filters menu in compressor, try using the geometry tab instead.

best,

Josh

Digital Media, Thought Equity Motion

[Joseph Barnett]

Hi Josh,

Thanks for your response, sorry ive been away for a week. Yes I agree, compressor is definitely superior it seems to be far superior for resizing and deinterlacing and is fast becoming my new friend. What im struggling to get my head around though is I figured that if you letterbox a 16×9 image it would fit to width and the black bars would fill the void. Unless my thinking is wrong then any other interpretation is distorting the image. Why is it that fcp distorts at 6.67, my only concern is that this method is by the manual, which makes me question the compressor outputs. Saying that if i size the file manually to fit in the fcp timeline without the file – distort of 6.67 it is exactly the same size as the compressor output.

– So it’s a question of which one is correct?
– im also intrigued if anyone knows about this distort ratio of 6.67 ? (i swear ive seen this number before in post production)

Im going to do some tests with our smoke artist tomorrow and see what his letterbox ouput generates, will report back.

Joseph

http://www.guiltybynature.com

[Josh Olenslager]

Joseph,

sorry that this slipped past me the first time, but 1024 x 576 is a PAL anamorphic frame size for SD already. Once you’ve taken that into FCP, are you turning the anamorphic function on in the FCP browser columns? I’ve just pulled a true HD clip (PROres HQ 1920×1080) into FCP and into Compressor and there is no distortion in either one once I add the 1.66:1 letterbox (Widescreen filter in FCP, geometry output letterbox in Compressor). The anamorphic aspect ratio might be where you’re seeing the distortion originate. Try setting FCP to recognize the 16:9 framing for the SD. (There’s an anamorphic column that you need to select — a check mark will appear when turned on.) And then check that against the letterbox and see if it fixes what you’re seeing. Both programs appear to be reading the letterbox mattes properly for me.

Let me know how it looks after you try it–or if you’ve already tried it, maybe I’ll attempt to duplicate the problem so I can see it more clearly. Good luck!

Josh

Digital Media, Thought Equity Motion

[Josh Olenslager]

Joseph,

Forgot to to say, by the by, that the 6.67 is just the slope for European letterbox.
1.66 pixels horizontal for every 1 pixel vertical. That’s why you’ll see, scope for example at 2.35:1, etc.

Josh

Digital Media, Thought Equity Motion

[Joseph Barnett]

Hi Josh,

Thanks for your reply. My thinking has been a little titled on this one so i tried my tests again. Im working with a 1K image it is natively 1024×576 not anamorphic. I can see where i stumbled before as my 1.66.1 eu standard is much more closer to the fcp one. it is still ever so slightly different though. The compressor seems to stretch it verticaly and crop ever so slightly. Im interested how you letterbox in FCP, currently i create a Pal time line and drop my 1K image straight in. the result is that it automatically scales the sequences to 75% with a 6.67 aspect distortion. I don’t normally apply the widescreen filter but if i do drop the effect on and switch it to 1.66.1 it crops ever so slightly at the top and bottom. Which still leaves me with a slight difference from the compressor 1.66.1 version. Thanks for all your feedback.

Joseph

http://www.guiltybynature.com