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Old Oct 29, 2009, 1:02 PM   #41
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On my monitor, I see no "yellow band," that you are referring to in your post. Please help me out, are you seeing something that I don't see?
Yes, that's the photo. There is a lightening and yellowing -- clearly visible (I'd say 'pronounced') along the line where a tonsure would be. There is visible yellowing around the front of the ear along the cheek as well. The ear could be picking up light from the very saturated yellow shirt -- but this seems unlikely to be the cause of the yellow tonsure. Yellowing around the _eye_ shows in the other portrait of your husband in this thread (he is wearing a different shirt), but there is no trace of the yellowing in the hair/forehead. It's not local color -- it seems to be an artifact in this photograph.

Here's a quick mark-up:
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Old Oct 29, 2009, 1:16 PM   #42
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It looks, to me, like a different light source coming from beside him (different temp than the WB is set)... but I'm no expert.
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Old Oct 29, 2009, 1:18 PM   #43
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The yellow is likely from the higher ISO Speeds being used for a given aperture and lighting, allowing higher ambient light levels at a warmer temperature compared to the amount of light being contributed by the flash being used (i.e., the ambient light was probably contributing too much to the exposure versus the light from the flash with the aperture, ISO speed and shutter speed settings, for the white balance being used by the camera.

You'll want figure out the behavior of any given camera model and adjust for those types of things for best results (using manual exposure, WB, etc. for even better results). Each camera tends to behave a bit differently in a given shooting conditon, and you may need to adjust technique/camera settings and more for best results once you understand a given camera's behavior.
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Old Oct 29, 2009, 1:32 PM   #44
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Thanks Jim and inneyeseakay. Bear with me -- I'm learning. Is the increase in sensitivity (ISO) linear across the visible spectrum? IOW, does the higher ISO allow for the recording of more of all light (and in this case there was yellow light) or does it favor certain hues/wavelengths (so that at this ISO it picked up yellow, but at other settings/with other cameras it might pick up other hues from the same set-up)?
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Old Oct 29, 2009, 1:41 PM   #45
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Originally Posted by Kriekira View Post
Thanks Jim and inneyeseakay. Bear with me -- I'm learning. Is the increase in sensitivity (ISO) linear across the visible spectrum? IOW, does the higher ISO allow for the recording of more of all light (and in this case there was yellow light) or does it favor certain hues/wavelengths (so that at this ISO it picked up yellow, but at other settings/with other cameras it might pick up other hues from the same set-up)?
The key is in this part of Jim's post:
Quote:
i.e., the ambient light was probably contributing too much to the exposure versus the light from the flash
I'm not as profient with wavelengths, so I'll talk in terms of 'temperature' The ambient light is 'warmer' than the flash. Warm light tends to give a yellow or orange tinge to it. When you have two different light sources as this shot did (one warm ambient light and one cool flash), it can be difficult to get a good white balance. THe easy solution is to change the camera's exposure (drop the ISO or increase shutter speed) so the ambient light isn't contributing as much - and let the flash be the very dominant light source. At the more difficult end of the spectrum, this is a situation where photographers will 'gel' their flashes. Basically putting something over the flash head which changes the hue of the light to match the ambient light source. Most of us don't want to do that. So, you're best to set up your camera to overpower the ambient light.

Now, you might ask - couldn't I just change the WB setting? The reason that doesn't work well in this situation is the ambient light is directional - i.e.. only on the one side of his face. So the left and right side of the image have two different white balances. So there isn't going to be a single WB setting that will work properly.
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Old Oct 29, 2009, 1:52 PM   #46
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For example, here's a photo from yesterday - to the right is an ambient light source. You don't get quite the same affect as in Sarah's photo because the cameras exposure is set low so the flash overpowers the ambient light. There is still SOME yellowness but not as pronounced. The downside is you lose some of the 'mood' of ambient light. Sometimes you may want that mood in the shot and other times not. But, at least when you're armed with the information here YOU can decide whether to let the temperature of the ambient affect the shot or not and not leave it up to chance.
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Old Oct 29, 2009, 2:33 PM   #47
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Good explanation of what's going on in Sarah's high-ISO shot -- thanks. Let me see if I understand: in that case one would lower the exposure to the point where the non-dominant light source showed nothing above some threshold for "light tones", so that all of the remaining "light tones" have the same temperature (which could be corrected universally (for this entire photograph) using a WB adjustment (if needed). Is that right?

Is in possible in pp to mask different areas of the image and apply different WB adjustments to each area?

Last edited by Kriekira; Oct 29, 2009 at 2:36 PM.
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Old Oct 29, 2009, 3:14 PM   #48
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You've got the idea. As to your question about PP - yes it's possible. But it's difficult to do well and have it look natural - at least in my experience. The difficulty is at the 'edges' of the area you're correcting and the transition to the image outside that area. Worthwhile for that wonderful image that you can spend 1/2 hour working on but I wouldn't want to spend that kind of time if I just took 15 images I wanted to keep. It's just easier to get it 'right' in-camera.
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Old Oct 29, 2009, 7:48 PM   #49
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I have had a huge computer glitch almost all day today, and I apologize for being "out of commission" for the better part of six hours. I am now back online and I think pretty much "fully operative," at least I hope so! The next hour or so will confirm that, for sure.

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Old Oct 29, 2009, 9:22 PM   #50
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I am still down with the computer. We will work overnight to attempt to get it back up and operating. Wow! That would be great.

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