Thread: Matching Color Temps

Reply to Thread
Results 1 to 6 of 6
  1. #1 Matching Color Temps 
    Junior Member
    Join Date
    Mar 2019
    Location
    Montana
    Posts
    9
    Trying to match the color temps in post between an Epic Dragon and a Gemini and cannot figure out why 5600k on the Dragon looks nice and warm yet 5600k on the Gemini much cooler. Both tints are 0. Any idea as to why this might be?
    Reply With Quote  
     

  2. #2  
    Senior Member Aaron Lochert's Avatar
    Join Date
    Oct 2013
    Location
    Tucson, AZ
    Posts
    1,158
    This is common. Don't get too caught up in the numbers. Different sensors can have different offsets. I see this all the time when I work as a colorist -- with many different camera brands. Don't be alarmed if you have to set each camera to its own set of WB numbers. If they look right, then they're right. So just WB them both by eye or even better: match both to a grey card.
    Reply With Quote  
     

  3. #3  
    Senior Member Jacek Zakowicz's Avatar
    Join Date
    Jun 2008
    Posts
    3,392
    We made a tool for that. Color chart in self contained backlit device.
    https://optitek.org/products/optimator-pro/
    Jacek Zakowicz, Optitek-dot-org, jacek2@optitek.org
    Professional Broadcast and Digital Cinema Equipment
    Reply With Quote  
     

  4. #4  
    Senior Member
    Join Date
    Aug 2008
    Posts
    4,269
    Matching RGB picker values between shots in the Resolve color page works well.
    Reply With Quote  
     

  5. #5  
    Senior Member
    Join Date
    Dec 2010
    Location
    Toronto & Vancouver
    Posts
    4,024
    ISO probably won't match either, FYI. Gemini typically defaults to ISOCal2 which will be a stop brighter at the same ISO (and maybe why it seems cooler as the blue channel would be comparatively "boosted" by a stop and, even though it's not noisy, maybe gives it a cooler bias.)
    Reply With Quote  
     

  6. #6  
    Senior Member
    Join Date
    Aug 2008
    Posts
    4,269
    Perhaps a better approach to this issue for exposure consistency would be to adjust the various IPP2 lut settings to match middle gray values and not worry about the ends. A low contrast LUT will not fill display REC709 IRE range on your monitor scopes, if it did it wouldn't be low contrast. Same with differences in high end rolloff that may cause the maximum IRE values for whites and near whites to shift in a non-linear fashion. But in REC709 display color space IRE scope value for middle gray doesn't change. Middle gray is middle gray is middle gray.

    As far as the raw exposure is concerned, with DSMC2 cameras you will have approximately a 5 or 6 stop linear DR range beyond the display range DR of 2.4 gamma REC709 which is 10 stops. Exposure for middle gray can vary by +/- 2 plus stops from the a mid point gray exposure ISO with equal highlight and shadow DR distribution without clipping raw sensor values.

    This is where shooting charts to determine ISO settings for your particular noise vs highlight protection preference for optimum exposure lies. I prefer using an incident light meter for these kinds of calibration tests as it will give a true ISO value for the light illuminating a middle gray chart test chart.
    Reply With Quote  
     

Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts