HowTo Resize 4K R3D to 2K R3D?

[SandeepDey]

I am working on a new workflow, in which I would like to shoot 4K (for obvious reasons) but post in 2K to keep a fairly uncomplicated FCP process.

So the question is, how can I resize 4K R3D footage to 2K R3D footage?

The objective to keep the 2K in R3D is so that we retain the best quality imagery until we are ready to commit to the grading.

[David Mullen ASC]

You can't. I mean, you could try, but it's not going to help, quality-wise, compared to converting 4K R3D to RGB and then resizing to 2K RGB. You aren't losing quality by converting to RGB unless you do it badly.

RAW means it's a monochrome image with a mosiac filter pattern in the original photography, making it very hard to downsample RAW to RAW, and doing that can lead to all sorts of odd artifacts -- you're much better off converting to RGB and then downrezzing to 2K RGB.

Storing the image as 2K RAW means that you'll get a worse 2K image than downrezzing from 4K RGB to 2K RGB. Because you'll have to generate RGB from a bayered 2K image, which ends up less than 2K in terms of measurable resolution because the bayer pattern in 2K RAW has 1K worth of green photosite information and .5K worth of red and blue individually from which to build an RGB image.

Storing as "RAW" only ensures the best quality if it truly is RAW -- what the sensor captured. Downsampling it RAW to a smaller RAW file does not mean you're getting more quality compared to converting it to RGB and then downsampling that -- in fact, it's worse as I pointed out because you're ending up with less information from which to generate 2K RGB.

[SandeepDey]

David,

Thanks a lot! You have cleared a nagging thought I have had. It is great to have the opportunity to pick some of the best brains in the business at the stroke of a key (and click of a mouse).

This makes things much simpler for me.

-Sandeep

[Graeme Nattress]

With the FCP /Color Native workflow, you can keep the native RAW 4k R3D, but render out nice 2k from that at the end.

As David points out, downsampling 3k to 2k while keeping it R3D just wouldn't work.

Graeme

[Dermot]

The same workflow is on offer with Avid DS, Scratch & Quantel... to name a few - so more than FCP/Color finishing tools in the spring of 2009....

All work with the 4K .r3d, and render / output to the desired target.. DPX for filmout, HDSR for video deliverables...

Nice to have choices... all these tools have their strengths and weaknesses, now one has more choices for the tool best suited for the job at hand.

Ta,

d.

[SandeepDey]

Thanks for your responses, gents.
-s