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SX200IS - Problem with red color in DNG

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Offline quid

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  • SX130IS
Re: SX200IS - Problem with red color in DNG
« Reply #10 on: 30 / January / 2011, 12:08:08 »
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I was going to ask for profile anyway :) I will post pictures for SX130 in profile generator thread.
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Offline aepl

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Re: SX200IS - Problem with red color in DNG
« Reply #11 on: 30 / January / 2011, 18:24:24 »
@vit40
The WB I used disappeared  :(. I thought that the WB was not serving any more.
Anyhow I will send to you new photos.
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Offline aepl

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Re: SX200IS - Problem with red color in DNG
« Reply #12 on: 30 / January / 2011, 18:56:45 »
@vit40

I uploaded the photo developed with a WB that is not the same I used to take the picture (but I think it is very similar).
The image was developed with iContrast off, with Custom Color with Sharpness in lowest setting and with full zoom.

http://www.megaupload.com/?d=T6OT7L7F
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Offline vit40

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Re: SX200IS - Problem with red color in DNG
« Reply #13 on: 31 / January / 2011, 04:09:22 »
hi aepl

This jpeg looks ok, WB also seems to be correct. Will try to make a profile later during the day or tomorrow (don't have time to do it right now), and also generate a test file for quid

Vit
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Offline aepl

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Re: SX200IS - Problem with red color in DNG
« Reply #14 on: 31 / January / 2011, 04:45:56 »
Hi vit40.
Do not spend time using an incorrect WB to make a profile. I will send a new couple of photos.
Thank you very much,
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Offline vit40

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Re: SX200IS - Problem with red color in DNG
« Reply #15 on: 31 / January / 2011, 05:53:39 »
No need for new photos, WB is exactly correct, whole gray area has RGB value 145,145,145

Stay tuned
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Offline vit40

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Re: SX200IS - Problem with red color in DNG
« Reply #16 on: 31 / January / 2011, 08:39:32 »
Here is the profile

http://www.megaupload.com/?d=P8PLNIAX

There are two versions. Both have the same lookup table and tone curve table, so that color rendering is the same. Difference is in color matrices that affect whitebalancing

- v1 has one color matrix borrowed from a dng
- v2 has two color matrices that I manually corrected according to your test photos, assuming tungsten illuminant for the first photo and daylight for the second

If you select As Shot whitebalance in ACR, both profiles will return the same result. But color temperature and tint calculated and displayed in ACR will be different for these profiles. So if you use some of WB presets in ACR, result will be different.

In case illuminant in those photos was significantly different from tungsten / daylight, and you see that for most photos, when WB is set to As Shot, temperature displayed in ACR is significantly different from 5500K / tint +10, I can correct this to be closer to the real value. Unfortunately, it is not possible to calculate this information without real test target and controlled illumination, so I have to set this manually and it is aproximation, hopefully better than in existing profile

Have in mind that in ACR you have to manually set corrections of vigneting, distortion, i-contrast etc to get close to result from the camera. Also, for some photos you will have to increase contrast or saturation (like in Digic III cameras) to get similar result as from camera, as color rendition depends on the scene (it seems to be fixed only in Digic II cameras), so in case of low contrast or low saturated picture, camera will boost it to get more pleasant result. Etc ...
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Offline aepl

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Re: SX200IS - Problem with red color in DNG
« Reply #17 on: 01 / February / 2011, 08:23:02 »
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Offline aepl

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Re: SX200IS - Problem with red color in DNG
« Reply #18 on: 01 / February / 2011, 14:19:09 »
Hi Vit40.
I am confused. I executed Exiftool and I can't understand the meaning of these values:

---- IFD0 ----
Bits Per Sample                 : 8 8 8
Samples Per Pixel              : 3

---- SubIFD ----
Bits Per Sample                 : 12
Samples Per Pixel              : 1

Thanks in advance.
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