[argyllcms] Re: Generated camera profile too bright

  • From: Nikolay Pokhilchenko <nikolay_po@xxxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Wed, 04 Apr 2012 01:07:17 +0400

Tue, 03 Apr 2012 21:43:16 +0200 "Andreas F.X. Siegert" wrote:
> > Or you could apply about a full stop's worth of positive exposure
>  > compensation during raw processing of your target shot and reprofile.
>  > Or reshoot the target so it doesn't need so much positive exposure
>  > compensation.
>  There is no way to generate an image that will be bright enough after
>  the switch to linear. The drop is just too radical.

May be there is the problem with RAW -> linear TIFF conversion as Graeme have 
You can do simple test: just shot a bulb or bright white object in daylight 
with defocusing and with overexposure for 3-4 stops. Then convert RAW into 
linear TIFF with Your workflow. Check the resulting TIFF. The saturated areas 
definitely should have 100% level in all three channel. If they have much less 
level, there is a problem in the RAW converter with camera sensor saturation 
levels. RAW channel values at fully saturated sensor area should become above 
100% level in resulting TIFF. The saturation point shouldn't be within 0..100% 
of linear TIFF scale. It should be slightly higher than 100%. Otherwise You'll 
get huge color casts on saturated areas of images because of linearity loss in 
"linear TIFF" data.

Other related posts: