Keying issue with REDCODE in Apple color

[Andrae Palmer]

I was having a problem keying a REDCODE clip in Apple Color. The HSL keyer just would not attach onto certain regions of color. I was attempting to secondary key the blue sky. I've attached images of the matte. I was dragging the HSL keyer all over the sky and as you can see in the matte these weird concentric lines started to appear. I was finally able to get a successful key by unchecking both hue and saturation. The image visually seems to have lots of blue sky to key from. I was informed by Creative Cow user Timo Teravainen that he had the same issues with the plugin and that keying works much better with shots transcoded to Apple ProRes.

If anyone else can expand on this it would be very much appreciated. I'm curious to the nature of those concentric lines in the matte and to why ProRes would work better with keying. BTW the original footage was shot with Formatt ND filters.

Image: http://farm4.static.flickr.com/3320/3244517254_9eb8fafbc6_o.png

Matte: http://farm4.static.flickr.com/3426/3241531260_61a95afacd_o.png

Luma waveform: http://farm4.static.flickr.com/3110/3244254762_37e8dcdec5_o.png

Chroma waveform: http://farm4.static.flickr.com/3088/3243633429_f8b84e4ff7_o.png

Here's a link to the post on Creative Cow: http://tinyurl.com/cr3fxb

 

[Shane Kelly]

in the setup room click on user prefs. On the far right what is your internal pixel format set at. Also check your grading proxy settings. Set everything as high as it goes and see what happens.
Shane.

 

[Andrae Palmer]

in the setup room click on user prefs. On the far right what is your internal pixel format set at. Also check your grading proxy settings. Set everything as high as it goes and see what happens.
Shane.

Shane,

I'm working in 12 bit color. Internal Pixel format set to 12 bit. I also changed everything to high while troubleshooting the problem and it didn't have any effect on the key.

 

[Shane Kelly]

Strange - it really looks like a low bit rate issue. I'll try and replicate it.
Shane.
P.s. I saw your creative cow post and it does seem that color is not interpreting the colorspace correctly.There should be a lot more chroma info in your waveform.
You should post the r3d file somewhere so we can play with it and find a solution.

 

[Uli Plank]

Yes, please post it for download, I'll try to help.

 

[Andrae Palmer]

I don't have the original R3D. Checked the size on the ingested quicktime wrapped file and its 12.41GB (2048x1024). Forgot that the clip duration was 8 minutes and 13 seconds long. I also double checked to make sure it is an ingested file rather than Apple ProRes... confirming that it is a rewrapped R3D. I don't know how to proceed with a file size so massive.

I think it's a bug in Color that it doesn't interpret the chroma information correctly in REDCODE codec to make a good HSL-key.

It looks like the secondaries-room takes the HSL-key information from the RED-raw colorspace (called Camera RGB in Color's Red Tab) instead of the colorspace that you choose in the Red-tab, and in RED raw there's not much chroma information.

If you render the same clip to ProRes in another colorspace, like REC709, it works much better with a HSL key.

--- Creative Cow

Can anyone else confirm/verify Timo's speculation for the cause of the problem?

 

[Nick Shaw]

I have had great success using HSL qualifiers in Color with native Red footage. Color does indeed go back to the RAW to key for secondaries, but that is in my opinion the correct thing to do. You do not want to be pulling a key from an image which has been pushed around in the primary room, you want it as 'clean' as possible. Obviously only the matte is taken from the RAW image, the secondary corrections are then applied to the results from the primary room.

Although your original clip may be 8 minutes long, if you set an in and out point in log and transfer, you can make a wrapped QuickTime which is small enough to upload.

 

[Mike Carter]

I've had the same trouble. I can pull a key, but can not effect the key no matter what I try to manipulate.