Thread: Pocket 4K red clipping

Page 2 of 11 FirstFirst 1234 ... LastLast
Results 11 to 20 of 104
  1. #11  
    Senior Member shijan's Avatar
    Join Date
    Apr 2012
    Location
    Odesa, UA
    Posts
    915
    Just checked samples and it feels like really something broken. Really strange. Red color highlights are distorted even when watching in LOG. Maybe wrong camera settings? Bad factory firmware calibration bug? Worst case - sensor defect. Did you ask BM support about this?
    P.S. Any digital sensor capture extremely wide color gamut so there is nothing special here.
    All my custom made accessories for BMMCC/BMMSC now available here https://lavky.com/radioproektor/
    Reply With Quote  
     

  2. #12  
     

  3. #13  
    Senior Member
    Join Date
    Mar 2017
    Location
    Melbourne, Australia
    Posts
    726
    Might be an issue with colour science 4?
    Reply With Quote  
     

  4. #14  
    Senior Member
    Join Date
    May 2012
    Posts
    1,163
    Looked at the samples in the Resolve color page using scopes. The shots are overexposed. The table lamp shot is way overexposed. Night street scene is about 1-1/2 stops overexposed Hot lights are hard clipped on the scopes regardless of how much you pull levels down.
    Last edited by razz16mm; 10-18-2018 at 06:49 PM.
    Reply With Quote  
     

  5. #15  
    Senior Member
    Join Date
    Mar 2017
    Location
    Melbourne, Australia
    Posts
    726
    Quote Originally Posted by razz16mm View Post
    Looked at the samples in the Resolve color page using scopes. The shots are overexposed. The table lamp shot is way overexposed. Night street scene is about 1-1/2 stops overexposed Hot lights are hard clipped on the scopes regardless of how much you pull levels down.
    But why is it that red lights look especially funky? where the white lights look very natural, I think something might still be off. There was a similar issue like this with ACES colour space where clipping lights where not represented correctly and required a work around. The fact that you can repair it says to me something isn't quite right.

    This is all from the Micro Cinema,

    So this first one is V1 colour science with the Extended Video Lut 4k + some saturation
    v1_1.6.3.jpg

    This one is V4 with extended video lut 4k
    v4_1.6.1.jpg

    And this one is V4 with saturation mapped
    V4 saturation mapped_1.6.2.jpg

    Now since this is all with a micro cinema I'm not sure on it's accuracy plus I'm using the extended video lut but it's something I noticed.
    Reply With Quote  
     

  6. #16  
    Senior Member shijan's Avatar
    Join Date
    Apr 2012
    Location
    Odesa, UA
    Posts
    915
    quote by CaptainHook:

    There are two parts to BMD Film, the log curve (gamma) and the "colour space" (gamut). The log curve is always optimized for the sensors dynamic range so the curve you get for cameras with different sensors will vary. Some will have more contrast than others. The gamut in previous versions would vary across cameras as well but with Gen 4 it is the same for any of our cameras using it and like Gen 3 it is more saturated to make it faster/easier to grade.
    All my custom made accessories for BMMCC/BMMSC now available here https://lavky.com/radioproektor/
    Reply With Quote  
     

  7. #17  
    I have also tried V4 color science with the BMPCC. The clipping is much more pronounced in the BMPCC4K files. It's not just an overexposed problem, because others colours are much better handled than the red. The saturation map method can fix this but with a counterpart on a prores file : you lose saturation in others area of your image.
    Reply With Quote  
     

  8. #18  
    Senior Member
    Join Date
    Mar 2017
    Location
    Melbourne, Australia
    Posts
    726
    Quote Originally Posted by slothorp View Post
    I have also tried V4 color science with the BMPCC. The clipping is much more pronounced in the BMPCC4K files. It's not just an overexposed problem, because others colours are much better handled than the red. The saturation map method can fix this but with a counterpart on a prores file : you lose saturation in others area of your image.
    I agree, something is off and will probably get fixed. Let's hope they already know about it.

    this picture from All2human over in the footage and frames thread exhibits the problem on the tail light of the motorbike in the far distance. https://www.flickr.com/photos/merumontanus/30473709277/

    looks like a hot pixel but it's just the red from the tail light and I don't see how it'd be over exposed?
    Reply With Quote  
     

  9. #19  
    Senior Member
    Join Date
    May 2012
    Posts
    1,163
    You are shooting with a 10 stop Prores video codec. Log or not that is all the DR you get. Clipped highlights look ugly and are not recoverable. The DR of this scene exceeds the DR of the codec and you have to experiment with exposure to find the best compromise between clipping highlights and clipping blacks. The red blooming is characteristic of 4:2:2 sub sampled chroma clipping.
    Raw gives you much more room to play with this kind of scene.
    Two screen shots from Resolve showing the scopes and the correct color managed settings for BM4K log. Straight log to the timeline and log to REC709.
    BMPCC4k log over.jpg

    BMPCC4k log to 709 over.jpg
    Reply With Quote  
     

  10. #20  
    Senior Member
    Join Date
    Mar 2017
    Location
    Melbourne, Australia
    Posts
    726
    What about my screenshots? They are Raw 3:1 where v1 looks completely different to v4?
    Reply With Quote  
     

Similar Threads

  1. Footage Clipping
    By Ameer Azari in forum Workflow
    Replies: 9
    Last Post: 09-21-2018, 03:15 AM
  2. Replies: 9
    Last Post: 03-21-2016, 06:32 PM
  3. Clipping Highlights and Shadows
    By rlr297 in forum DaVinci Resolve
    Replies: 3
    Last Post: 01-23-2015, 02:34 PM
  4. Clipping and Glare Question
    By Vanguard in forum General Discussion
    Replies: 9
    Last Post: 01-02-2015, 08:38 PM
  5. BMC Highlight Roll-off/Clipping
    By Brandon in forum General Discussion
    Replies: 22
    Last Post: 11-06-2012, 06:48 PM
Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •