LCC changing exposure balance of image

NN1826691

• January 10, 2011 02:41

Hi there,

I am trying to now use capture one to process my leaf MOS files in Capture One 6. The problem I am having is that when I go to the LCC tool and highlight both an image RAW file and white card RAW file to analyse (in order to remove color shift) once I have clicked the analyse button it changes the exposure quite dramatically making it very bright. It also says during the analyse process "Lens Cast Calibration contains clipped data. Bad color casts may occur". Can anyone shed any light on what I am doing wrong?

regards

Stephen

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  thowi

  • January 10, 2011 09:20

  [quote="NN182669" wrote:
  I am trying to now use capture one to process my leaf MOS files in Capture One 6. The problem I am having is that when I go to the LCC tool and highlight both an image RAW file and white card RAW file to analyse (in order to remove color shift) once I have clicked the analyse button it changes the exposure quite dramatically making it very bright. It also says during the analyse process "Lens Cast Calibration contains clipped data. Bad color casts may occur". Can anyone shed any light on what I am doing wrong?

  basically the white reference shot must not show clipping. In other words: when you shoot the white reference exposure must be corrected so that there is no clipping in the historgram of the actual white reference capture. As a thumb rule push exposure by two stops (relative to the exposure of the scene).
  Also... it sounds you are shooting some kind of white balance card to create LCCs? Those cards are not appropriate - you need a dedicated white plexi plate with high density & diffusion. You have to hold (or mount) the plate directly on the lens... in other words: you have to shoot the light that is coming through the card... not the light that is reflected by the card.
  From the P1 reference manual:
  http://www6.pic-upload.de/10.01.11/tr9h7zkoq27e.jpg
  
  Hope this helps.

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  NN1826691

  • January 10, 2011 10:06

  Thanks but I know this. My white cards using a dedicated white diffuser that comes with leaf digital backs are fine and so are my exposures. I render good results in leaf software at removing Lens casts. My problem is with not understanding how to remove lens casts in the capture one software .

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  thowi

  • January 10, 2011 10:19

  okay.
  so maybe this is the issue:
  

  when I go to the LCC tool and highlight both an image RAW file and white card RAW file to analyse

  
  the LCC analysis refers to the primary selected variant. So if the capture of the actual scene is the primary variant, the LCC tool will analyse the scene. Make sure the white reference shot is the selected primary variant for the LCC analysis.
  Basically you don't have to select the capture of the scene in the first instance. Just select the LCC shot and perform the LCC analysis. Then select your (scene-) capture and apply the LCC you've just created.

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  NN1826691

  • January 10, 2011 12:38

  Many thanks for your explanation, I understand it now and it has pleasing results. 😄

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