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12-26-2008, 02:32 AM   #1
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weird lines with manual white balance

so i wanted to write a more sensationalist title like "white balance gone wild" but i resisted.

has anyone ever seen this before? i was taking pictures with my k10d that i purchased last march with a fa 50mm 1.4 lens. It was working perfectly for the beginning of the night even with manual white balance.

i started noticing weird colored lines and it was really apparent when i tried to take a sample shot for the manual white balance. as you can see, its not crazy lighting that is causing the weird color abnormalities, it changes with the position of the lens. also, it was intermittent as other shots in between those seemed normal.

thanks for your input.

kevin

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12-26-2008, 08:26 AM   #2
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What do you mean?
I don't see it.
12-26-2008, 08:52 AM   #3
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I think he is talking about the shadow line if you look at the vertical and the pics below you can see a section that is darker than the rest of the image. is it me or does the lens look like it had trouble with focusing ?
12-26-2008, 09:20 AM   #4
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Ah, ok, now I see it!
Part of the image is more yellow and the other part is of a bluish white.
And it changes when you turn the camera.

It looks like the blue channel has a problem.
No idea.

Is Gordon Goodsman around?

12-26-2008, 11:10 AM   #5
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QuoteOriginally posted by hsuperb0i Quote
so i wanted to write a more sensationalist title like "white balance gone wild" but i resisted.

has anyone ever seen this before? i was taking pictures with my k10d that i purchased last march with a fa 50mm 1.4 lens. It was working perfectly for the beginning of the night even with manual white balance.

i started noticing weird colored lines and it was really apparent when i tried to take a sample shot for the manual white balance. as you can see, its not crazy lighting that is causing the weird color abnormalities, it changes with the position of the lens. also, it was intermittent as other shots in between those seemed normal.

thanks for your input.

kevin
did you have to heavily process these shots? If they were VERY dark in exposure and you had to pull them up quite a bit this can happen...
There has never been an explanation for the toning (usually one side reddish, other blue). It is suspected to be some quirk of the ADC.
12-26-2008, 11:30 AM   #6
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hey thanks for your replies.

please don't look at the focusing =p, these were just shots i selected to demonstrate the different colors, i had it on manual. there was no post processing done at all to these pictures. I am referring to the blue lines and the weird shadows that were intermittent and not part of the lighting when i took the picture.
12-26-2008, 12:12 PM   #7
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What do you mean it changes with the position of the lens? Angle it's pointed? Focus? Portrait od landscape shot? Not sure what that means as this is a prime lens. I am assuming you meant Poprtrait or landscape as the 2 pictures of the kitchen show the yellow half in the same place on the sensor.
It's tough to know and you say other shots in between were good.
It's almost as if part of the sensor WB'd to one temp and part WB'd to another temp.
12-26-2008, 12:22 PM   #8
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sorry for my poor descriptions. i am referring to landscape vs. portrait mode.

it does seem as if different parts of the sensor were WB'd to different temps. When taking the sample shot on manual mode, i would see a weird brownish area in the middle of the picture and sample to that. is there anything that could cause different parts of the sensor the be WB at different temps?

12-26-2008, 01:04 PM   #9
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Questions. What kind of lights and where? Florescent, incandescent or mixed? What shutter speeds?

DAZ
12-26-2008, 01:22 PM   #10
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You have at least two different sources of light in the photos and both have different temperatures. The shadow in the last shot is different color than the light right next to it, and it really seems that the blue light source is blocked by the cup. It also looks like you used a lot of jpeg compression on these web versions and that makes it a bit more difficult to see any glitches
12-26-2008, 01:29 PM   #11
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yea i was concerned about the light sources as well when i was shooting. it was fluorescent kitchen lighting with an off color plastic covering. there were some bulbs that looked more off than others, maybe cuz of age. however, the differences between the 3rd and 4th portrait and landscape pictures, and the consistent horizontal line when in landscape mode, make me feel like it wasn't something with weird light sources. yea sorry about the jpeg compression i "exported to email" in lightroom.

the shutter speeds:

1/180
1/250
1/750
1/500
1/500
12-26-2008, 02:03 PM   #12
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Florescent lights vary in brightest and that also means color with time. This time is over a 60th (in the USA and 50th in some countries) of a second. This can be more noticeable with older lights and mixed lighting. If the shutter speed is fast you can get part of this change in part of the photo and not other parts. In mixed lighting part of the photo can get light from the different lights and look OK to the eye but the camera with its better ability to see color can see the shadows. This could be that the top of the wall is a different color or as you look along the wall. You can see it in what look like shadows when to you r eye you donít see any shadows.

Florescent lights are hard to get the color correct. Mixed lighting (florescent and incandescent for example) is the next hardest. Low pressure sodium are literally impossible to get the color correct.

DAZ
12-26-2008, 05:39 PM   #13
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QuoteOriginally posted by DAZ Quote
Florescent lights vary in brightest and that also means color with time. This time is over a 60th (in the USA and 50th in some countries) of a second. This can be more noticeable with older lights and mixed lighting. If the shutter speed is fast you can get part of this change in part of the photo and not other parts. In mixed lighting part of the photo can get light from the different lights and look OK to the eye but the camera with its better ability to see color can see the shadows. This could be that the top of the wall is a different color or as you look along the wall. You can see it in what look like shadows when to you r eye you donít see any shadows.

Florescent lights are hard to get the color correct. Mixed lighting (florescent and incandescent for example) is the next hardest. Low pressure sodium are literally impossible to get the color correct.

DAZ
Obvious test for fluorescent lighting as the culprit: Put the camera on a tripod and stop the lens down until you get a shutter speed of 1/30s or less. Shoot in RAW. See if colour banding disappears. I suspect it is a result of the FL lighting flicker so should be gone with long exposures.
12-26-2008, 08:04 PM   #14
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Upon further review

QuoteOriginally posted by hsuperb0i Quote
so i wanted to write a more sensationalist title like "white balance gone wild" but i resisted.

has anyone ever seen this before? i was taking pictures with my k10d that i purchased last march with a fa 50mm 1.4 lens. It was working perfectly for the beginning of the night even with manual white balance.

i started noticing weird colored lines and it was really apparent when i tried to take a sample shot for the manual white balance. as you can see, its not crazy lighting that is causing the weird color abnormalities, it changes with the position of the lens. also, it was intermittent as other shots in between those seemed normal.

thanks for your input.

kevin
Send it in, it's broke. Can't be the lighting since you rotated it 90 degrees and the pattern followed. If lighting issues it wouldn't have. As I stated earlier k10 had some color issues in underexposed shots. This could just be an advanced stage of it. I suspect hardware failure of the sensor or ADC.......
12-26-2008, 08:17 PM   #15
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QuoteOriginally posted by jeffkrol Quote
Send it in, it's broke. Can't be the lighting since you rotated it 90 degrees and the pattern followed. If lighting issues it wouldn't have...
Exactly right, I think. Rotating the camera would have no effect if the problem was due to mixed lighting.
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