[argyllcms] Re: Camera profiling generation and blown highlights
- From: Pascal de Bruijn <pmjdebruijn@xxxxxxxxx>
- To: argyllcms@xxxxxxxxxxxxx
- Date: Fri, 22 Jan 2010 17:51:06 +0100
On Fri, Jan 22, 2010 at 4:21 PM, Klaus Karcher <lists@xxxxxxxxxxxxxxxxx> wrote:
> Pascal de Bruijn schrieb:
>>
>> On Fri, Jan 22, 2010 at 11:18 AM, edmund ronald <edmundronald@xxxxxxxxx>
>> wrote:
>>>
>>> Seeing *who* is doing the asking, I would make them available.
>>> If you want help, why don't you make the Raw chart images, and test
>>> (subject images) available?
>>
>> I included the subject image... as a native camera linear rgb 16bit
>> tiff...
>>
>> I can upload the other images when I'm home again...
>
> Looks like the char was pretty much underexposed and your image rather
> overexposed.
The chart's exposure should well be in the ballpark...
When I view the chart in UFRaw with gamma 2.2, the O12 patch has a
value of about 130, which should be in the ballpark area for L=50.
This is about the exposure which CMP recommends.
Please note, I'm profiling from a linear gamma target...
Indeed the image is much overexposed in area's, the scene just had a
huge dynamic range.
When I apply my own profile, to normally exposed RAWs, the (final)
exposure looks fine.
> "RGB(Y).pdf" shows neutral patches in your original TI3 file vs Y.
>
> I scaled the RGB values in your TI3 file by 100/82.3096 (see attachment
> "CMP-test.ti3") and made some new profiles (e.g with colprof -u). The
> results are more feasible now (whereas the profile of course can't fix
> overexposure).
I'll try it later tonight, thanks. I never spotted the -u option before.
I'll be doing some more experimenting, and I'll report back, possibly
providing more samples.
Regards,
Pascal de Bruijn
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