September 30, 2014, 12:33:48 PM

Author Topic: White balance, how to determine?  (Read 4454 times)

neuroanatomist

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Re: White balance, how to determine?
« Reply #15 on: August 14, 2013, 09:36:55 AM »
somewhat related - does anyone know how to determine what color temperature was selected when using auto white balance?  I'm using DPP and the "info" window doesn't reveal it.

That's an annoyance with DPP.  I use DxO Optics Pro, and it shows the actual color temperature that's been applied.
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Re: White balance, how to determine?
« Reply #15 on: August 14, 2013, 09:36:55 AM »

Pi

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Re: White balance, how to determine?
« Reply #16 on: August 14, 2013, 09:49:13 AM »
somewhat related - does anyone know how to determine what color temperature was selected when using auto white balance?  I'm using DPP and the "info" window doesn't reveal it.
Thanks!

You can use EXIFToolGUI but that is not the most elegant solution. I can see the color temp value there but not the Tint one (must be there somewhere).

Last time I used DXO, it reported different color temp and tint values than LR.

Anther remarks: when you shoot with Daylight WB, you cannot see in LR what the camera thought was the right one. That is a good starting point very often, and it is good to have. LR has its own Auto one.

neuroanatomist

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Re: White balance, how to determine?
« Reply #17 on: August 14, 2013, 10:20:27 AM »
You can use EXIFToolGUI but that is not the most elegant solution. I can see the color temp value there but not the Tint one (must be there somewhere).

Last time I used DXO, it reported different color temp and tint values than LR.

Interestingly, for an image shot in mixed lighting, when I open the RAW file in various converters, I see the following for the As Shot settings:

DxO: 3740K, Tint 0
ACR: 3600K, Tint +30
Aperture: 3495K, Tint +26

Which is 'right'?  Maybe none...

Exiftool just reports 5200 in the color temperature field, so that's apparently just a default value.  It may be that the color temperature for Auto WB is not recorded as a Kelvin value in the EXIF, but rather the converter must deduce the WB settings from other data/metadata. 
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Pi

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Re: White balance, how to determine?
« Reply #18 on: August 14, 2013, 10:44:49 AM »
You can use EXIFToolGUI but that is not the most elegant solution. I can see the color temp value there but not the Tint one (must be there somewhere).

Last time I used DXO, it reported different color temp and tint values than LR.

Interestingly, for an image shot in mixed lighting, when I open the RAW file in various converters, I see the following for the As Shot settings:

DxO: 3740K, Tint 0
ACR: 3600K, Tint +30
Aperture: 3495K, Tint +26

Which is 'right'?  Maybe none...

Exiftool just reports 5200 in the color temperature field, so that's apparently just a default value.  It may be that the color temperature for Auto WB is not recorded as a Kelvin value in the EXIF, but rather the converter must deduce the WB settings from other data/metadata.

From one of my shots (boldface and the separation line mine):

WB_RGGBLevelsAsShot             : 2260 1024 1024 1613
ColorTempAsShot                 : 5786
WB_RGGBLevelsAuto               : 2260 1024 1024 1613
ColorTempAuto                   : 5786
WB_RGGBLevelsMeasured           : 2344 1020 1027 1529
ColorTempMeasured               : 6314
-----------------------------------------------
WB_RGGBLevelsDaylight           : 2144 1024 1024 1742
ColorTempDaylight               : 5200
WB_RGGBLevelsShade              : 2461 1024 1024 1444
ColorTempShade                  : 7000
WB_RGGBLevelsCloudy             : 2310 1024 1024 1574
ColorTempCloudy                 : 6000
WB_RGGBLevelsTungsten           : 1651 1103 1103 2932
ColorTempTungsten               : 3200
WB_RGGBLevelsFluorescent        : 1908 1061 1061 2618
ColorTempFluorescent            : 3674
WB_RGGBLevelsKelvin             : 2144 1024 1024 1742
ColorTempKelvin                 : 5223
WB_RGGBLevelsFlash              : 2325 1024 1024 1558
ColorTempFlash                  : 6129

The values below the line seem to be the same for each shot.

Now, open it in LR, and I get: Temp=5300, Tint=0. Go figure. I do not have DXO installed right now to try with it.
« Last Edit: August 15, 2013, 09:14:27 AM by Pi »

crasher8

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Re: White balance, how to determine?
« Reply #19 on: August 14, 2013, 10:59:28 AM »
people keep trying to reinvent the gray card. Just use it.

Sporgon

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Re: White balance, how to determine?
« Reply #20 on: August 14, 2013, 11:13:42 AM »
no, some try to make better profiles than they from adobe etc who are more general than  specific for the camera
take d800 as one example, a tool who can be profiled a lot better, the camera is like a fine tune instrument compared with eg Canon's color filters that are thinner and gives not as many shades of  a color

Just as well; you can profile the green cast out.

paul13walnut5

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Re: White balance, how to determine?
« Reply #21 on: August 14, 2013, 12:20:55 PM »
qpcard and software.


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Re: White balance, how to determine?
« Reply #21 on: August 14, 2013, 12:20:55 PM »

Mr Bean

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Re: White balance, how to determine?
« Reply #22 on: August 15, 2013, 08:57:08 AM »
Accurate colour in flower pictures demands camera profiles and the easiest way to get them is with an X-Rite Color Passport.

+1 on the X-Rite Color Checker Passport.  Small, light, easy to slip in a bag, and quite tough.
Thanks all, for the replies and ideas. I'll try the grey card / white card as a test over the coming weekend. But, the Colour Checker Passport seems (to me at least) to be the most scientific approach to the issue. When I've tried to use the eye ball approach, that is, does it look right on the screen, usually through sheer dumb luck it works, sometimes :)
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Re: White balance, how to determine?
« Reply #22 on: August 15, 2013, 08:57:08 AM »