Click here to go to the first RED TEAM post in this thread.   Thread: Black Shading Nightmares

Reply to Thread
Page 3 of 10 FirstFirst 1234567 ... LastLast
Results 21 to 30 of 97
  1.   Click here to go to the next RED TEAM post in this thread.
  #21  
    Red Team Deanan's Avatar
    Join Date
    Jan 2007
    Posts
    3,847
    Rick,
    What you're seeing is the sensor at a very cold state compared to what it was black shaded at.
    If the ambient temperature is constantly cold, then you'd want to black shade at the colder temp.

    Martin,
    The sensor in Epic is running at over 30x faster than a 5DII.
    Running a sensor at high speeds makes things like black shading exponentially
    more complex to both create the black shade as well as apply it in real time
    at high frame rates.

    Andrew,
    1.7.10 and later has a more complex black shading mode that is necessary
    for high speed sync. In upcoming builds we'll be adding more options for
    black shading that will both improve the time it takes as well as flexibility.
    Reply With Quote  
     

  2. #22  
    Banned
    Join Date
    Dec 2006
    Posts
    3,775
    Deanan, What's strange is that I had the Epic running for 3+ hours straight and then I noticed this issue after I cranked up to 2000 iso and had the lens cap on. I re-did the black shade, and the gradient effect was horizontally flipped. The cold / warm test was done late last night. It seems inconsistent. Any idea what this could be? I'm letting the camera roll right now for 40 minutes straight and am going to speed up the footage to see the gradient dissipate over time. Then I'm going to black shade again, let it cool down for a few hours and try the test again in the morning.
    Reply With Quote  
     

  3. #23  
    Senior Member JanneJansson's Avatar
    Join Date
    Aug 2008
    Location
    Sweden
    Posts
    1,067
    I'm not anywhere as knowledgeable as Deanan of the workings of Epic sensor, but things that I can think that can affect a sensor surface from side to side are:
    How is camera stored? Upside up, or on side? Have camera been close to strong magnetics? Even if you are sure, have you tested blackshading with a black cloth over camera just to make sure this is no light leak (take care so it don't overheat)? Have you tried 2.02 firmware?

    My guessing is that the sensor "bakground noise" gets louder the hotter is gets, and making a blackshade on a hot sensor removes more "noise" and make a cleaner image, but at same time make it tiny bit less sensitive and work less good at cold temps. But a hot-blackshaded camera will not show picture correct until it get hot. (Very apparent on some Phantom cameras)

    I treat camera as unexposed film, because it's just what it is. You only have this sensor and this should be good foreveeeer*!
    In any case I would get a support ticket for this.

    *until you can upgrade to Dragon :)
    JJ
    Reply With Quote  
     

  4.   Click here to go to the next RED TEAM post in this thread.
  #24  
    Red Team Deanan's Avatar
    Join Date
    Jan 2007
    Posts
    3,847
    Quote Originally Posted by Rick Darge View Post
    Deanan, What's strange is that I had the Epic running for 3+ hours straight and then I noticed this issue after I cranked up to 2000 iso and had the lens cap on. I re-did the black shade, and the gradient effect was horizontally flipped.
    That depends on what temp the earlier blackshading was done at.
    It sounds like it was done at a higher ambient temp.

    Email me a single frame r3d.
    Reply With Quote  
     

  5. #25  
    Banned
    Join Date
    Dec 2006
    Posts
    3,775
    I will get you an R3D shortly

    Question, since black shading calibration gives you two calibration maps, a factory setting and a user1 setting, could you theoretically make the factory setting setup for indoor shooting and user1 setup for colder outdoor shooting?
    Reply With Quote  
     

  6. #26  
    Banned
    Join Date
    Dec 2006
    Posts
    3,775
    BTW, Thank you for helping me understand this better.
    Reply With Quote  
     

  7. #27  
    Senior Member Les Dittert's Avatar
    Join Date
    Sep 2011
    Location
    Los Angeles
    Posts
    1,543
    My guess is that the black shade may actually be trying to warm up the sensor to get more data points for hotter sensor conditions.
    Otherwise, a black shade should take a couple of minutes max, even with a ton of frame averaging. I have done code to black shade sensors, I see no reason other than what I describe.
    -Les Dittert
    Reply With Quote  
     

  8.   Click here to go to the next RED TEAM post in this thread.
  #28  
    Red Team Deanan's Avatar
    Join Date
    Jan 2007
    Posts
    3,847
    Quote Originally Posted by Rick Darge View Post
    I will get you an R3D shortly

    Question, since black shading calibration gives you two calibration maps, a factory setting and a user1 setting, could you theoretically make the factory setting setup for indoor shooting and user1 setup for colder outdoor shooting?
    In theory yes but ideally, having the ability to do an additional setting would be ideal.
    Our goal is to make that viable given the current constraints as well as other options
    for more flexibility.
    Reply With Quote  
     

  9.   This is the last RED TEAM post in this thread.   #29  
    Red Team Deanan's Avatar
    Join Date
    Jan 2007
    Posts
    3,847
    Quote Originally Posted by Les Dittert View Post
    My guess is that the black shade may actually be trying to warm up the sensor to get more data points for hotter sensor conditions.
    Otherwise, a black shade should take a couple of minutes max, even with a ton of frame averaging. I have done code to black shade sensors, I see no reason other than what I describe.
    -Les Dittert
    The process is very compute intensive to get the best results.
    Reply With Quote  
     

  10. #30  
    Banned
    Join Date
    Dec 2006
    Posts
    3,775
    Hey Deanan, I sent you an R3D trim. Thanks again..

    I noticed that when turning on false color, I don't see a discrepancy in the evenness of the sensor noise until I go over 2000 ISO, that's when the false colors begin to split. Does anyone else notice this with their Epics? Could someone put the port cap on their Epic, turn the body on from a cold start, crank up to the MAX ISO and turn on False Color and tell me if your image looks even?

    Thanks! Hopefully I solve this issue soon!
    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