SX40HS dcp profile and chdk colors

dvip

451

« on: 05 / January / 2013, 18:08:44 »

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Matching chdk DNGs colors with the colors I get form JPGs has been difficult.
Is there a dcp file for the SX40HS?
I'm using Rawtherapee (from where I can use dcp files) to process the DNGs.

I found a dcp (Canon_PowerShot_SX50_HS-simple.dcp) for the SX50HS but where do I find one for the SX40HS.

http://rawstudio.org/svn/rawstudio/trunk/profiles/

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philmoz

3441

Re: SX40HS dcp profile and chdk colors

« Reply #1 on: 05 / January / 2013, 18:27:10 »

Quote from: dvip on 05 / January / 2013, 18:08:44

Matching chdk DNGs colors with the colors I get form JPGs has been difficult.
Is there a dcp file for the SX40HS?
I'm using Rawtherapee (from where I can use dcp files) to process the DNGs.

I found a dcp (Canon_PowerShot_SX50_HS-simple.dcp) for the SX50HS but where do I find one for the SX40HS.

http://rawstudio.org/svn/rawstudio/trunk/profiles/

AFAIK the sensor is the same so you should be able to use the SX50 profile (use a hex editor to change SX50 to SX40 in the file).

Phil.

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CHDK ports:
sx30is (1.00c, 1.00h, 1.00l, 1.00n & 1.00p)
g12 (1.00c, 1.00e, 1.00f & 1.00g)
sx130is (1.01d & 1.01f)
ixus310hs (1.00a & 1.01a)
sx40hs (1.00d, 1.00g & 1.00i)
g1x (1.00e, 1.00f & 1.00g)
g5x (1.00c, 1.01a, 1.01b)
g7x2 (1.01a, 1.01b, 1.10b)

dvip

451

Re: SX40HS dcp profile and chdk colors

« Reply #2 on: 05 / January / 2013, 22:04:05 »

@Phil, I did try the Canon_PowerShot_SX50_HS-simple.dcp
but the colors are still different than the jpg's, especially reds.
Yep, both the SX40HS/SX50HS have the same sensor.
Could be that Canon does something with the jpg colors.
Where do chdk's DNGs get their colors from? CAM_COLORMATRIX1?

« Last Edit: 05 / January / 2013, 22:14:08 by dvip »

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philmoz

3441

Re: SX40HS dcp profile and chdk colors

« Reply #3 on: 05 / January / 2013, 22:40:06 »

Quote from: dvip on 05 / January / 2013, 22:04:05

@Phil, I did try the Canon_PowerShot_SX50_HS-simple.dcp
but the colors are still different than the jpg's, especially reds.
Yep, both the SX40HS/SX50HS have the same sensor.
Could be that Canon does something with the jpg colors.
Where do chdk's DNGs get their colors from? CAM_COLORMATRIX1?

Yes, CHDK DNG colors are set by CAM_COLORMATRIX1 and cam_CalibrationIlluminant1.

You're not going to be able to easily match the in-camera jpeg colors - there's too much that is unknown about the tone curve applied by the camera.

Phil.

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CHDK ports:
sx30is (1.00c, 1.00h, 1.00l, 1.00n & 1.00p)
g12 (1.00c, 1.00e, 1.00f & 1.00g)
sx130is (1.01d & 1.01f)
ixus310hs (1.00a & 1.01a)
sx40hs (1.00d, 1.00g & 1.00i)
g1x (1.00e, 1.00f & 1.00g)
g5x (1.00c, 1.01a, 1.01b)
g7x2 (1.01a, 1.01b, 1.10b)