View Full Version : Post FX and 4k
J.D. Frey
03-26-2007, 03:43 PM
The DWP is gearing up to shoot quite a bit FX and chroma key shots. I was wondering- would compressed 4k footage be ok for chroma key work with a final res in the 2k or HD range. I'm assuming that the pixel density of 4k RAW would give me a better result but I'm wondering how much better.
Chris Kenny
03-26-2007, 04:01 PM
The one REDCODE green screen frame Red has posted so far keyed flawlessly (one click with Keylight in Shake), and supposedly REDCODE is better now than it was then. That's probably all anyone can tell you until NAB.
Bruce Allen
03-26-2007, 04:27 PM
Yes. Definitely.
Bruce Allen
www.boacinema.com
MikeCurtis
03-26-2007, 05:19 PM
yeah, you'll be happy with the results (assuming lensed/lit/focused/shot well)
-mike
P Andersson
03-26-2007, 08:30 PM
The one REDCODE green screen frame Red has posted so far keyed flawlessly (one click with Keylight in Shake), and supposedly REDCODE is better now than it was then. That's probably all anyone can tell you until NAB.
anyone know where to get that file again
J.D. Frey
03-26-2007, 08:59 PM
yeah, you'll be happy with the results (assuming lensed/lit/focused/shot well)
-mike
ha ha- you mean 17 grand and it won't make my movie for me?
anyone know the link for that chroma test image?
Chris Kenny
03-26-2007, 09:11 PM
Here's (http://www.cinematography.net/Red/comp-matrix.html) the page with the REDCODE frame. Also an uncompressed version of the same frame for comparative purposes.
J.D. Frey
03-27-2007, 06:58 AM
thanks for the link Chris
Barend Onneweer
03-27-2007, 11:22 AM
You really can't judge whether the compression will degrade the performance in post based on a single still.
When you pull a key on compressed material, the compression artefacts are going to show up as jittering edges. You won't notice them on a still. As good as the stills on that site look, they're not too useful when trying to evaluate how the image holds up in post.
That said, the image also represents an older version of REDCODE compression (supposedly it's better now), and downsampling to 2k after doing post will reduce some of the side-effects.
My guess is that it will be okay.
Gavin Greenwalt
03-27-2007, 02:51 PM
Actually I can't imagine it being a problem especially if you shoot chromakey footage like I usually do: Vistavision style.
Turn your red on its side. Tada 8k RAW. If your deliverable is 1080 that means any possible compression artifacts will be LONGGGGG supersampled out.
J.D. Frey
03-28-2007, 06:51 PM
that is a really cool idea- and so simple! I feel dumb for not thinking of it myself. It would be great for any portrait style subject. Thanks!
Gavin Greenwalt
03-29-2007, 12:15 PM
Don't feel dumb, just be glad people don't approach you with nothing but an SD camera and ask "Can you make an HD version".... Wellllll.....
I also had some fun when the RED was first announced making a quick 4k composite using the HVX and a DSLR... just to see what I could expect :)