I was given a big batch of 2K Cineon files by our local film lab, and need to output these to HDCAM-SR. The lab is using Assimilate Scratch to color grade film scans, and then to generate these .cin files. When I import these into the DS, I either need a LUT or I need to manually set white point, black point, gamma etc. The lab can't give me a LUT. How can I figure out what settings to use for the log to lin conversion?

Use Linear(Log>Log, Lin>Lin) make sure to turn off clamp. Black point 0 white point 1023, setup your storage to 16 bit and import 1 frame. Export the same frame and check your black and white point against the original. They should be exact. If there is a slight difference in the blacks, contact Softimage and ask for the DPX fix. I've seen a very slight difference in the blacks(100ths of a point) before applying this fix. Also, if you want to use Photoshop to check the before and after, make sure to apply "Big Endian Byte Encoding" or Photoshop won't be able to open the file.

What is the framesize coming in? Are you bringing in 2K full aperature and spitting out HD frames 4:4:4? If so, then open up a 24 fps 1080 4:4:4 sequence capture your scans and spit out to HDCamSR.

Without the proper Lut the files will look flat on your monitor, but when they are recorded out to film, they will look correct. The only issue would be if you are conforming, adding fades, compositing etc., then you would need to be set up in a properly calibrated environment, with a way of applying a 3DLut.

Michael

Hi Mike,

Thanks for that advice. Sounds like this method is intended to preserve the look of the original scan, correct?

My problem is that I have to make these scans look good for broadcast TV. So, here's what we did. We scanned through the scenes in one complete film reel, and came up with our own custom white and black points, and they more or less work for video. So far, we've now captured 3 reels into the DS, and the shadow details aren't crushed, and highlights are not blown out. I know this is not the ideal method, but the director is pushing us to get it out the door for the Cannes Marketplace. Eek....

mrmikster:

Use Linear(Log>Log, Lin>Lin) make sure to turn off clamp. Black point 0 white point 1023, setup your storage to 16 bit and import 1 frame. Export the same frame and check your black and white point against the original. They should be exact. If there is a slight difference in the blacks, contact Softimage and ask for the DPX fix. I've seen a very slight difference in the blacks(100ths of a point) before applying this fix. Also, if you want to use Photoshop to check the before and after, make sure to apply "Big Endian Byte Encoding" or Photoshop won't be able to open the file.

What is the framesize coming in? Are you bringing in 2K full aperature and spitting out HD frames 4:4:4? If so, then open up a 24 fps 1080 4:4:4 sequence capture your scans and spit out to HDCamSR.

 

Without the proper Lut the files will look flat on your monitor, but when they are recorded out to film, they will look correct. The only issue would be if you are conforming, adding fades, compositing etc., then you would need to be set up in a properly calibrated environment, with a way of applying a 3DLut.

 

Michael

Right, I assumed since it was graded in Scratch that you didn't want to touch color. Did they provide any charts for you to reference? If not, you've only got your eyes.

Michael

Thanks for your prompt reply, I appreciate it. To answer your question, they did provide a color chip chart. When we applied our custom (best guess) settings, the chip chart had a somewhat high black level and the colors were desaturated. And yet, many of the scenes were contrasty and highly saturated..and others were low con. So I'm not sure what I should have done with their chip chart, as a reference for setting white, black, and gamma.

David

Oh, I wish they had provided some kind of reference chart. In the end, one of the producers came over to our facility and approved our "best guess" settings by reviewing part of one reel (out of the 6 that eventually came our way). This is not the way I like to work!