Half Debayer vs Full Debayer

[Colin Hubick]

Hi all, I'm curious to get some feedback from other Red users out there that have printed their footage to film.

The question that I am curious about is the final quality differences between processing your footage out at 2k resolution (from 4k source) using a half debayer (high) or outputting 2k resolution (from 4k source) using a full debayer. Then printing that footage back to film.

Has anybody else done this test, and if so what were your results?

Thanks
Colin

 

[Trevor Meier]

Absolutely, positively use a full debayer if going out to film.

 

[Dan Hudgins]

Sharpness...

Sharpness...

You might also want to look at outputting 4K TIF, then resample down to 2K.

If you over sharpen the 4K images you can get more aliasing when going down, so its best for the 4K images to be a little soft.

It can help to blur the 4K images a little before they go down to 2K. How the 4K images are resampled can affect the noise in the finished images as well as the aliasing. You may want to blur the blue primary more than the green and also blur the red a little.

Film is not as sharp when projected as your monitor, probably, so if you over sharpen the images you are mostly just adding noise and ringing to your filmout.

http://www.celco.com/FormatResolutionTableKodakCineon.asp

Some film recorders output about 16:9 less than 2K wide, i.e. 1828 X 1026, see the Celco link. How the filmrecorder does the resize from 2048 to 1828 can add aliasing and noise, so in some cases it might be better to do that resize yourself with slower but better software(?).

I just uploaded a new version of my CC software to improve the downsize issue since 4K images from RED ONE can be sharper than 4K film scans. The new code I made resizes using 100% of the 4K pixel data rather than a resample that skips pixels. Some people might use blur and resample that skips pixels since that is faster, but using all the 4K data without loss can maybe give lower noise and cleaner resize, maybe. You can try it and see what way looks best to you. Do you have a 2K monitor to look at the frame images on with 1:1 pixel display modes? If your frame viewer is going to resize to fit the screen size you have, that can complicate telling what the images will look like, 1:1 pixel display mode is almost always best.