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05-28-2010, 09:36 PM   #1
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White Balance Problem

Maybe this is just too much for any camera to handle, but I was curious to see how my K-x would handle two different light temperatures in the same shot. Both shots were taken moments apart at dusk in fading light, halogen light coming through the window out onto the open outdoor porch. First is with no flash, Auto White Balance; I tried banishing the blue with the Tungsten setting on another shot, but got the same result. The second shot was with flash and shows the appx natural color of the scene. If I pointed the camera away from the lit window, everything returned to normal. Would the shade setting have helped here, or is the camera/sensor just incapable of faithfully rendering a scene like this without flash?


Last edited by lectrolink; 08-15-2012 at 11:11 PM.
05-28-2010, 09:54 PM   #2
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Well, if the room has a blue tint, then it'll appear blue on your image, right? The flash shoots white light, so obviously the WB will end up being different.

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05-28-2010, 11:06 PM   #3
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it's not exactly a problem

It's more like a realisation of the laws of physics.

Your camera's sensor can only have one white balance setting at a time. What you have is two light sources with very different temperatures. You either need to choose to depict one light source correctly or pick a compromise.

Chances are the custom functions on your camera are set for "set white balance to flash when flash is used". You can change this setting if you want to try and shoot a jpeg with a compromise white balance.

If you take the same shot in RAW and then try and select the white balance in your raw converter you'll see what I mean.

The only way I can think of to represent the two different light temperatures correctly would be to make an image with two layers in photoshop, one using flash white balance (on top) and one tungsten, then mask the window of the flash balanced layer, invert the selection and delete. This will allow you to merge the two different images to get the effect you want.
05-29-2010, 01:46 AM   #4
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I understand that the camera can apply only one white balance at a time. What I really am asking is how can I select a setting (without flash) that will expose the outside scene (with the lounge chairs) correctly in this circumstance, without regard for the color of the window light. I could find no setting to expose for the outside that would get rid of the blue cast. I want to do this in JPG, not RAW. Any ideas?

05-29-2010, 02:03 AM   #5
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QuoteOriginally posted by lectrolink Quote
I understand that the camera can apply only one white balance at a time. What I really am asking is how can I select a setting (without flash) that will expose the outside scene (with the lounge chairs) correctly in this circumstance, without regard for the color of the window light. I could find no setting to expose for the outside that would get rid of the blue cast. I want to do this in JPG, not RAW. Any ideas?
You will have to select the white balance manually. Probably take a couple of attempts to get it right.
05-29-2010, 03:44 AM   #6
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QuoteOriginally posted by lectrolink Quote
I could find no setting to expose for the outside that would get rid of the blue cast.
If none of the WB presets work then do a custom WB. In this mode you take a shot of the scene only to obtain a WB setting for the next shots. I do this in "spot measuring" mode so that the camera only samples a small central portion of the image. Check your camera manual for how to do an in-camera custom WB setting.
05-29-2010, 03:59 AM   #7
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I like the blue one it has some effect compared to the white one.

I sometimes use fluorescent light white balance on a morning outdoor gloomy weather to add more blue to the sky instead of gray sky.

Try to take the same shot with no flash and play with all your white balance settings so you will know better.

The meta data or exif data of your shots will aid you in reviewing and comparing your shots.
05-29-2010, 04:00 AM   #8
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This is one area where the K7 excels. Mixed lighting situations are hard for any camera, but truthfully, I seldom have to change the temperature on my K7 photos (unlike both the K20 and K10 before it).

On the other hand, this is a reason to shoot in RAW -- once you figure out the appropriate temperature and tint settings, you can apply it to all photos taken in this setting and fix it all at once.

05-29-2010, 04:32 AM   #9
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QuoteOriginally posted by lectrolink Quote
I understand that the camera can apply only one white balance at a time. What I really am asking is how can I select a setting (without flash) that will expose the outside scene (with the lounge chairs) correctly in this circumstance, without regard for the color of the window light. I could find no setting to expose for the outside that would get rid of the blue cast. I want to do this in JPG, not RAW. Any ideas?
Sunlight is between 5200-5600 K in temperature. Tungsten is around 2500.

Set the WB to Sunlight or Flash (around 5500 K) and don't use the flash, and your porch will render correctly. The window will read orange.

Setting your WB to Tungsten (Incandescent/Light Bulb) will render any sunlight as blue like you are seeing.
05-29-2010, 05:47 AM   #10
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QuoteOriginally posted by lectrolink Quote
I understand that the camera can apply only one white balance at a time. What I really am asking is how can I select a setting (without flash) that will expose the outside scene (with the lounge chairs) correctly in this circumstance, without regard for the color of the window light. I could find no setting to expose for the outside that would get rid of the blue cast. I want to do this in JPG, not RAW. Any ideas?
Setting a custom white balance is the best way to do this. There are a number of ways to do this including trial and error but use of a white card or similar device (expodisk or similar) will allow you to do this routinely. I use a Balens now on my k10/k20. Here is a link to a video for it used on a Nikon. I think Pentax does this very simply. And I use this a lot these days even though I shoot in Raw where I can adjust this which ever way I want. However, if I've set my white balance right in the camera I don't have to do much adjustment to the raw file later for that issue.

Another way to go is with a Whibal card. Digital Photography - RawWorkflow.com - WhiBal Certified Gray Card for White Balance

What I like about these is that you can use them to set a custom white balance in your camera or set them in the image and later adjust the image with a shot of the card in it.

I'm sure there are other ways to do this as well.
05-29-2010, 06:40 AM   #11
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QuoteOriginally posted by lectrolink Quote
I understand that the camera can apply only one white balance at a time. What I really am asking is how can I select a setting (without flash) that will expose the outside scene (with the lounge chairs) correctly in this circumstance, without regard for the color of the window light. I could find no setting to expose for the outside that would get rid of the blue cast. I want to do this in JPG, not RAW. Any ideas?
generally in situations like this, I shoot with daylight.

you have hard lines, you can select regions to apply WB in post processing
05-29-2010, 08:38 AM   #12
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QuoteOriginally posted by lectrolink Quote
First is with no flash, Auto White Balance; I tried banishing the blue with the Tungsten setting on another shot
That's completely backwards. The tungsten setting is for eliminating *orange* color casts, since tungsten light is orange. If you want to eliminate a blue cast via WB, then choose a WB setting for light that actually *is* blue, like Cloudy. Or, as others suggested, Daylight, for a somewhat more natural looking result that tries to achieve a balance between the outdoor light (which really *is* blue), and the indoor light (which really *is* orange).

the flash shot, BTW, is *not* what the scene actually would have looked like, it might represent something closer ti how you *perceived* the scene, but that's because your eyes and bran have their own built-in AWB function that caused you to not notice just how blue the light really was. The truth would have been not as blue as the first picture, of course - it appears the camera basically selected the tungsten preset for you because of the halogen light in the scene, but still noticeably cooler than the flash shot. The flash shot looks as neutral as it does for two reasons not just because the camera chose an appropriate WB setting, but also because the flash *changed* the color of the scene, drowning out the blue light of dusk with its own more neutral light.

QuoteQuote:
Would the shade setting have helped here, or is the camera/sensor just incapable of faithfully rendering a scene like this without flash?
It's the other way around - the flash *changed* the color of the scene, to more closely resemble what your brain fooled you into seeing, but it's most definitely *not* a faithful reproduction fo the actual scene in the way it would have been if you had chosen the Daylight or Cloudy settings.
05-29-2010, 12:47 PM   #13
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As I mentioned, I tried all of the WB presets, including shade and cloudy with no appreciable difference in any of them. While the lighting was dim, there was no blue cast I could see; the flash photo was close to what the colors looked like to me. Seems the stronger window light was what the camera was reacting to in matrix metering the entire scene.
I think Class A has the right idea--custom WB using a small portion of the area to meter. I'll try that.
Thanks for all the advice...
05-29-2010, 04:48 PM   #14
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As I suggested, set the WB yourself. Do it with the indoor lights off ! Then switch them on again for your picture.
05-30-2010, 12:44 PM   #15
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QuoteOriginally posted by lectrolink Quote
As I mentioned, I tried all of the WB presets, including shade and cloudy with no appreciable difference in any of them.
That sounds unbelievable to me. Can you post sample images demonstrating this? If you don't get *vastly* different images between the cloudy and the tungsten preset, something is very wrong with your camera.

QuoteQuote:
While the lighting was dim, there was no blue cast I could see
Right - as I said, the eyes and brain are very good at doing at AWB for you and tricking you into not seeing color casts. But measure the scene with a colorimeter sometime, or simply create a scene with mixed lighting in which your eyes are doing their AWB for the incandescent light (like being indoors but having the light dusk visible through the window) and you can get your eyes to show you the scene as it really is. Like I said, it's not *as* blue as your picture, but your picture would *not* have come out that blue had you used the daylight or cloudy presets.
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