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Author Topic: Setting custom white balance at capture stage.  (Read 4435 times)
NigelC
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« on: October 17, 2012, 11:08:37 AM »
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My application of white balance correction is pretty rudimentary. I always shoot Auto WB and then use the eyedropper in ACR on the nearest thing I can see to an 18% grey and then fiddle around with fine tuning sliders until it looks about right.

This does not work with the Sigma DP2M I have just acquired, because the WB adjustments for the raw files in SPP don't allow that sort of fine tuning. Therefore, if I have time, I need to set a custom white balance before I take a shot. Now the Sigma manual says fill the screen with a white sheet or similiar, but "white" encompasses a pretty wide range of tints. If I were to get a Macbeth Passport Colour Checker and use the off-white WB target, would that be accurate, or should I find something bright white? If they say white, presumably a known mid-grey, such as a Canon soft pouch case will not do.
I need some guidance here.
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Colorado David
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« Reply #1 on: October 17, 2012, 11:31:07 AM »
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I also use auto WB and adjust in post for much of my still shooting, however I've worked primarily in video production for thirty years now.  With a video camera I've always used a Portabrace white balance card.  Where you place the card when doing the white balance has considerable effect on the results.  For example when I want a slight warm white balance in daylight, I place the card in the shade.  The shaded daylight will have a bit more blue and the resulting white balance will be a little to the warm side.  I know that there are sets of white balance cards available that will achieve the same results but have never used them.
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NigelC
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« Reply #2 on: October 17, 2012, 12:22:13 PM »
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Interestingly, the Canon 5D2 manual reference to custom white balance says use a plain white object, but then later says an 18% grey card will give a more accurate result. Probably need to experiment
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BartvanderWolf
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« Reply #3 on: October 17, 2012, 12:50:11 PM »
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Interestingly, the Canon 5D2 manual reference to custom white balance says use a plain white object, but then later says an 18% grey card will give a more accurate result. Probably need to experiment

Hi Nigel,

The important thing is that the surface has to have a spectrally neutral reflection, you can make a neutral gray card look whiter by adding 2 stops of exposure time, just don't clip the color channels in Raw.

Cheers,
Bart
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NigelC
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« Reply #4 on: October 17, 2012, 02:49:36 PM »
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Hi Nigel,

The important thing is that the surface has to have a spectrally neutral reflection, you can make a neutral gray card look whiter by adding 2 stops of exposure time, just don't clip the color channels in Raw.

Cheers,
Bart
OK thats straightforward the way Canon does custom white balance  - I'll have to check with the DP2M - setting custom white balance doesn't actually involve taking a shot so it may not record an exposure compensation setting
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deejjjaaaa
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« Reply #5 on: October 17, 2012, 05:02:37 PM »
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Interestingly, the Canon 5D2 manual reference to custom white balance says use a plain white object, but then later says an 18% grey card will give a more accurate result. Probably need to experiment

XRite Passport WB target is a quite neutral = http://www.rmimaging.com/information/ColorChecker_Passport_Technical_Report.pdf

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Graystar
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« Reply #6 on: October 17, 2012, 09:11:01 PM »
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I use an RMImaging product called the Digital Gray Card.  It's a 4"x6" plastic reference that's 3mm thick so it's very sturdy.  It's spectrally neutral, and has a very nice matte surface which helps with accuracy.  RMImaging says it's for white balance only, but I also use mine to set exposure.  I carry it in my back pocket, and anytime I step into new light I pull it out, perform a custom white balance, and set exposure if the light is constant.  Takes about 10 seconds.  At 15 bucks it's the least expensive of the good-quality references (Whibal, Expodisc, X-Rite) and I get a lot of use out of it.

I always try to set a custom white balance because I've found that it always looks better than trying to play with the sliders myself.  The human eye is a terrible tool for setting color.  If we could set color accurately, then we wouldn't need hardware to calibrate our monitors.
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NigelC
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« Reply #7 on: October 18, 2012, 04:18:45 AM »
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Just to clarify, the linked report indicates the WB card on the Passport requires a camera producing raw files that can be processed through ACR/LR or through DNG; therefore it can't be used with the DP2M.
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pflower
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« Reply #8 on: October 18, 2012, 05:07:38 AM »
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Actually you can set the white balance in SPP for a DP2M.  It is not under the white balance settings but below them on the Color Adjustment wheel.  Choose the eyedropper there and then click on a neutral target.  This will adjust the image accordingly.  I find SPP pretty dreadful but just about useable.  I tend to set a custom white balance with a reading off a Xrite Colour Passport from time to time when shooting. That at least gets you into the right area.  Fine tuning can then be done in Lightroom or CS5.

 Alternatively put a neutral grey card or whatever in a frame, then adjust the white balance as above in SPP.  Then save that setting and apply it to all the other pictures taken in the same lighting.



My application of white balance correction is pretty rudimentary. I always shoot Auto WB and then use the eyedropper in ACR on the nearest thing I can see to an 18% grey and then fiddle around with fine tuning sliders until it looks about right.

This does not work with the Sigma DP2M I have just acquired, because the WB adjustments for the raw files in SPP don't allow that sort of fine tuning. Therefore, if I have time, I need to set a custom white balance before I take a shot. Now the Sigma manual says fill the screen with a white sheet or similiar, but "white" encompasses a pretty wide range of tints. If I were to get a Macbeth Passport Colour Checker and use the off-white WB target, would that be accurate, or should I find something bright white? If they say white, presumably a known mid-grey, such as a Canon soft pouch case will not do.
I need some guidance here.
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jeremypayne
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« Reply #9 on: October 18, 2012, 05:29:22 AM »
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I always try to set a custom white balance because I've found that it always looks better than trying to play with the sliders myself.  The human eye is a terrible tool for setting color.  If we could set color accurately, then we wouldn't need hardware to calibrate our monitors.

I calibrate to get my prints to match my screen ... not because my eyes lead me to choose 'bad color'.
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NigelC
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« Reply #10 on: October 18, 2012, 09:19:38 AM »
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I was under the impression the colour adjustment wheel was a completely different algorithm to the WB adjustment
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pflower
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« Reply #11 on: October 18, 2012, 01:39:19 PM »
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It most probably is, but the WB adjustment only works with pre-sets that may or may not suit you.  The color adjustment wheel will at least set an overall colour balance to the image which (if you click on a grey card) at least emulates a WB setting and gets you into the right ballpark.  As an experiment I made a shot in sunlight with an x-rite colorchecker passport in the picture.  I exported one version from SPP with default WB settings and another version having clicked on the neutral square in the color checker.  Both imported into LR4.  When using the WB balance eyedropper in LR4 on the file exported with SPP's pre sets it pretty much matched the color corrected tiff from SPP.

I am not particularly interested in the technology behind the calculations - they seem to work whether you call it WB or color adjustment and you end up in pretty much the same place.

I was under the impression the colour adjustment wheel was a completely different algorithm to the WB adjustment
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deejjjaaaa
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« Reply #12 on: October 19, 2012, 01:38:03 AM »
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Just to clarify, the linked report indicates the WB card on the Passport requires a camera producing raw files that can be processed through ACR/LR or through DNG; therefore it can't be used with the DP2M.
no, it does not... it is just a neutral patch that you use to set a WB.
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stamper
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« Reply #13 on: October 19, 2012, 03:24:03 AM »
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Quote

I always try to set a custom white balance because I've found that it always looks better than trying to play with the sliders myself.  The human eye is a terrible tool for setting color.  If we could set color accurately, then we wouldn't need hardware to calibrate our monitors.

Unquote

I see a contradiction in this statement. You are using your eyes for a better looking image and then saying they are a terrible tool. At the end of the day the eyes are all we have to judge the final output. The word accurate is also misplaced in the discussion. Pleasing would be a better solution. If you show someone the image that you have produced then they can only judge it by their eyes - and like or dislike it - and they don't know what the original looked like or what hoops the photographer jumped through to get there. Every image made looks different from the original rendered raw data and the final output because they have to be processed. Finally what is the point of getting an "accurate" WB or colour and then changing the hue, contrast and saturation to taste? Just start off with something reasonable and edit to suit your vision. Smiley BTW we use monitor hardware to balance out the colour that the manufacturers haven't done properly in the first place?
« Last Edit: October 19, 2012, 03:26:14 AM by stamper » Logged

Graystar
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« Reply #14 on: October 19, 2012, 09:14:09 PM »
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oy
friggin
vey

As soon as saw your name as the last poster I knew it was a response to my post to put me down.  It's been two years since I proved you utterly wrong on the AF question, and you still can't get over it.  Sad...


I see a contradiction in this statement.
Yes well, we already know you tend to see what you want to see.


Quote
[rambling dribble of an attack clipped]
First, the point of an accurate WB is color accuracy.  Some people aren't producing art...there are product, documentary, scientific, etc. photographers and color accuracy is very important to them.  Second, as the xrite color challenge proves, some people have trouble differentiating colors.

http://www.xrite.com/custom_page.aspx?PageID=77&Lang=en

Third, the problem with your "pleasing" as a solution is that what's pleasing one moment isn't pleasing the next when people are trying to set WB sliders by eye.  That's because the eye's white balance is changing as you're trying to set these colors.  In other forums when someone posts an image where they can't seem to get the white balance right, a white balance set from the whites of the eyes will invariably be praised as the best looking. When the color of the light isn't an element of the scene, an accurate white balance gives pleasing colors.  Of course, an artist can manipulate an image and create a different set of pleasing colors.  But that doesn't diminish what you get from an accurate white balance.


Quote
BTW we use monitor hardware to balance out the colour that the manufacturers haven't done properly in the first place?
Goody for you.  And Jeremy Payne calibrates to get prints to match his screen. Whoopee!  I never tied calibration to the task of white balance or anything else.  My comment was about the eyes, not calibration.  I said that we use hardware to calibrate because our eyes can't do it.  I said nothing about calibration itself.  You simply read what you wanted to read and attacked what you wanted to attack...like you usually do.

Obviously, I'm tired of your attacks on my posts.  Get yourself a new hobby.
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stamper
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« Reply #15 on: October 22, 2012, 02:36:47 AM »
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Paranoia seems to be running through your post. Remembering something from two years ago in which you thought you had a "victory" does you no favours.I think it would be better if you tried to answer other poster's points on the merit of what they stated rather than attacking them personally? It might even win you friends? Have you been following this thread?

http://www.luminous-landscape.com/forum/index.php?topic=71583.0;topicseen

If you read it you might find it debunks some of your theories better than I can. Then again an open mind is needed. Wink
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Graystar
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« Reply #16 on: October 22, 2012, 03:20:27 PM »
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Paranoia seems to be running through your post. Remembering something from two years ago in which you thought you had a "victory" does you no favours.I think it would be better if you tried to answer other poster's points on the merit of what they stated rather than attacking them personally? It might even win you friends? Have you been following this thread?

http://www.luminous-landscape.com/forum/index.php?topic=71583.0;topicseen

If you read it you might find it debunks some of your theories better than I can. Then again an open mind is needed. Wink

It's amazing how ignorant you become when your primary goal is to attack me, rather than making meaningful contributions to the forum.  It takes a thoroughly misguided mind to find that a thread full of opinions debunks theories I never gave.

I don't like you at all, I don't care for anything you have to say, and I wish you would stop responding to my posts.
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stamper
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« Reply #17 on: October 23, 2012, 02:51:27 AM »
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Reply 13 wasn't an attack on you personally but merely a difference of opinion regarding your ideas about photography. This forum exits for that purpose.

Quote

I don't like you at all,

Unquote

You don't know me so that is silly? Don't take anything I state as personal but only an attempt at a rebuttal of your ideas. Now can we get on with the differences in our approach to photographic subjects? Smiley
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digitaldog
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« Reply #18 on: October 23, 2012, 10:45:24 AM »
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IF your are making images (not copy work, not scientific capture), the correct white balance is the rendering you the creator wish to express. There is no correct or accurate answer. Work to produce as close to WYSIWYG on display and other output media to honor that preferred, subjective color.

You can put a spectrally neutral card in a lot of locations within a scene and get butt ugly color.

What's nice about the Passport is the option to use a 'neutral' patch or patches which graduate warmer and cooler so you can sample to taste (then use those nice Tint/Temp sliders if you wish). When it looks right to you, it is the right value.
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Andrew Rodney
Author “Color Management for Photographers”
http://digitaldog.net/
stamper
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« Reply #19 on: October 24, 2012, 02:39:24 AM »
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Couldn't have stated it better myself. This is what I am driving at but Andrew is certainly far more articulate and knowledgeable than myself. Hopefully some harmony can now be achieved?  Smiley
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