Red Camera Greenscreen

[skean]

Hi

This is my first post so please go easy on me ;)

I'm primarily a motion graphics artist but the editing facility I work at is being asked to do more and more Vfx work.

The situation I have is as follows:

A program the facility is working on has some greenscreen effects stuff in it that has been Shot on RED camera. The program output its 1080 and the greenscreen has been shot at Either 2k or 4k resolutions. The RED footage was originally conformed into the avid at 1080 and one of our Online editors has attempted to do the key and composite. However he’s had some real struggles with spill etc so it has been suggested that we in Gfx now do the vfx. We’ve
Successfully got the original RED media into Premiere using an .aaf from the avid with links to the original media. So I now have the 2k & 4K r3d files on my premiere timeline, which is great however I’m now ready to begin the keying and am wandering what the best approach would be.

I know you can alter the source settings of the RED media and this is where my knowledge especially regarding colour spaces etc comes to an end. The red media as it comes on to my timeline is at the settings shown in the attached file. As you can see the footage is really quite bleached out and I was wandering if
There was anything I can do at a source level to help overall before keying in after effects / Nuke?

Also, I’ve been scouring fourms etc looking for tips and help and some suggestions I’ve seen is to work on dpx File sequences as opposed to the red files. Any thoughts or advice on that? Any performance gains on working
on dpx as opposed to r3d file? If so how can anyone suggest I get the dpx sequence out and at what settings as when i've tried thus far the greenscreen file sequence looks remarkably different to r3d file?

Any help or advice on this would be greatly appreciated. I’d really like to get this right with regards to the colour Space etc as its not something that we deal with often but are likely to have to do more of in the future.

[scrimski]

If so how can anyone suggest I get the dpx sequence out and at what settings as when i've tried thus far the greenscreen file sequence looks remarkably different to r3d file?If you can manage to export an xml you may use RedCine for generating dpx-files. On my last project we used Color for this, which did an OK job apart from messing up spanned clips(ie wrong in/out).
there's also The Foundry's Storm and Crimson(for which you need RedCine 3.xx, not the current version and an MacOS prior to 10.6) and RedRushes.

We used Redspace/Redgamma throughout the project, no pregrade, at 3200 kelvin, 4K all the way though it was scaled down to 2K in comp and comformed to 1080 in FCP.

[skean]

Appreciate the reply Scrimski. Colour spaces give me brain strain. Doing my best to learn more about them.

[scrimski]

I'm not so sure about them either, usually I'm doing offline edits using w/ R3d footage converted to ProRes clips and don't care too much about the look/color, because it's handed over to usually a grader involved after the picture lock/comp.
Spend some time with the lead compositor testing out various options and he decided to use those, in his opinion the skin tones were the most important information.

[skean]

I completely hold my hands up to not knowing enough about colour spaces. It seems to be an area where either people know it inside out or little at all. I'm definitely in the latter.

[aaronber]

Normally you would convert your R3D source into EXR or DPX sequences because they are faster to work with. There is no debayering and in general you can pull random frames of an image sequence off of your HDD faster. You can certainly use DPX, and it is a solid workflow, but you could also use EXR which has some advantages. You can use RedCine to do the image sequence conversion.

Your DPX or EXR sequences may look very different because tehy are in a different color space, but that is OK because you can just color grade them back to what you want them to look like. You can get all technical about it, but you are probably going to put some sort of color grade on it anyway so just make it look the way you want. It is important to remember that the conversion from R3D to DPX leaves you with a 12-bit log file, so you have room to grade it, but technically you loose a little bit of information from the original R3D. However, in practice you don't loose enough information to make much of a difference and the convenience is worth it.

If you are working in Nuke or AE it doesn't really matter that much how you transcode your footage into DPX, EXR, or keep it as an R3D because you can make any color or brightness adjustments in your compositing application. I usually just do a straight encoding using the defaults of the R3D to an EXR sequence, if it needs to be more saturated then I saturate it in the composite to help with the key.

[skean]

Thanks Aaron also for your response. I take your point in terms of colour correction etc...but with it being greenscreen surely there is preferable colour settings to use when working either with the r3d files or the dpx sequence so as not to create problems with the key?

[aaronber]

Sure there are preferable color settings, but it will change from shot to shot. That is why I prefer to tweek the colors in the comp. Like Scrimski said, RedSpace and RedGamma are a good place to start with your Color space and gamma curve, white balance is important, so pick something that compliments the way it was shot to preserve skin tones. If you work with the R3D in AE or Nuke then you can make all of these adjustments and see how they affect your key. If you have many similar shots to do it is often useful to pick one and experiment with the R3D for a bit to find some good general settings and then do a batch process to convert them all to image sequences so you can get through the bulk of the shots faster.

[skean]

Appreciate your time and help on this.

[Gravy]

Ask the dop what it was shot in. :p Not always easy I know, I think the settings used on camera should be in the metadata somewhere though. Have you tried using red's own tools? Mainly RedCine X.

It's best to get this sorted out rather than doing colour corrections etc to change the space.

[skean]

Hi Gravy. Yeah the camera settings are as the image i've attached in my initial post. Thats exactly how the media is as i get it. My issue is I don't know what to convert it to ( if necessary ) and whether to change the colour space, gamma curve etc. If i drag the original r3d file into AE it looks different to how it looks in Nuke, and any dpx or exr files ive converted out of Redcine X look different again. I understand that these are all being viewed in different colour spaces...though which is correct and which is best to work with is where i'm falling down. I don't know enough about colour spaces and the science behind it i guess and a lot of the stuff i'm reading expects some knowledge to begin with. Can anyone suggest any good documentation regarding colour spaces?

[scrimski]

Not always easy I know, I think the settings used on camera should be in the metadata somewhere though.That's the easiest part actually. Just open the R3D-file in RedCine or RedAlert and it's all there.