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03-12-2010, 09:35 AM   #16
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I don't think temperature is the problem; I've been shooting my K-x outdoors in British Columbia all winter without colour balance issues like this. Overall I've been very impressed with the AWB on the K-x, I rarely change mine. Switching to tungsten while outdoors is not typical K-x behavior, so you may have a bad copy - or you accidently changed it yourself. Not trying to be insulting, but it takes time to figure out a new camera.

Before doing anything else I'd shoot a bunch more, trying out the different settings. If you're convinced it's nothing you are doing, I'd suggest some voodoo cures (things that work sometimes for no apparent reason):

-take the batteries out, let the camera sit for a few minutes so any residual charge in any capacitors drains, then put in some freshly charged batteries.
-reinstall the firmware.

That's all I've got, I'm afraid. Let us know how it works out.

03-12-2010, 09:50 AM   #17
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BTW, does the K-x normally always report WB as "Auto" if it was in fact set that way? My K200D does. But I could imagine an implementation where in AWB mode, the camera simply picks the preset it thinks most appropriate (ie, similar to how Auto Pict chosoes from the various Scene modes), and the EXIF might actually report not "Auto" but rather the selected preset.

What I'm trying to asecertain is whether the camera actually switched to Tungsten mode "for real" - which would clearly and obviously be a camera defect - or if it simply picked the Tungtsen preset for some as yet unknown reason that *might* turn out to be a legitimate misreading of the lighting. Not that the latter should really be a common occurence, so I'm pretty doubtful, but we should be sure we know what we're looking at here.
03-12-2010, 10:02 AM   #18
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QuoteOriginally posted by Marc Sabatella Quote
BTW, does the K-x normally always report WB as "Auto" if it was in fact set that way? My K200D does. But I could imagine an implementation where in AWB mode, the camera simply picks the preset it thinks most appropriate (ie, similar to how Auto Pict chosoes from the various Scene modes), and the EXIF might actually report not "Auto" but rather the selected preset.

What I'm trying to asecertain is whether the camera actually switched to Tungsten mode "for real" - which would clearly and obviously be a camera defect - or if it simply picked the Tungtsen preset for some as yet unknown reason that *might* turn out to be a legitimate misreading of the lighting. Not that the latter should really be a common occurence, so I'm pretty doubtful, but we should be sure we know what we're looking at here.
I just looked at the EXIF on a bunch of my K-x pictures that were shot with AWB, and they all say 'White Balance: Auto', regardless of whether it was sunny or overcast. These pictures all had different temperature and tint settings in ACR, so I would say the K-x will always say 'Auto' if it is indeed set that way.
03-12-2010, 11:28 AM   #19
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6 x left => tungsten accident

QuoteOriginally posted by bikecoboss Quote
I just looked at the EXIF on a bunch of my K-x pictures that were shot with AWB, and they all say 'White Balance: Auto', regardless of whether it was sunny or overcast. These pictures all had different temperature and tint settings in ACR, so I would say the K-x will always say 'Auto' if it is indeed set that way.
Yes, you're right. You'll only get Tungsten in the EXIF by selecting Tungsten manually. The AWB of the K-X is quite good, much better than on the K10.

My only explanation is that the OP by accident hit the 4-way button selector a few times. Hit the left button 6 times and you're on Tungsten. No need to press the ok button, I can imagine that happened by accident.

03-12-2010, 07:09 PM   #20
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QuoteOriginally posted by tomtor Quote
My only explanation is that the OP by accident hit the 4-way button selector a few times. Hit the left button 6 times and you're on Tungsten. No need to press the ok button, I can imagine that happened by accident.
I could certainly buy that if I only had 1 bad pic. But out of 62 images shot in a space of about 1 1/2 hours, 11 showed the problem, and they were not consecutive images. The longest "run" of bad images was two. So there must be some other explanation. The extended exif data I posted above clearly shows that the camera was set to "auto" WB, but the exposure was made using the tungsten value (the two entries are widely separated in the exif data posted). Apparently the K-x does not adjust WB across a continuous range of color temps, but when in auto, selects the preset it thinks most nearly matches the conditions.

As posted by someone else above, since I shoot in .DNG + .JPG mode, the images are salvageable when processing the .DNG file. But something happened. It did not repeat today, when I shot 30+ pics under almost identical conditions.

Tim
03-12-2010, 08:45 PM   #21
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I saw this on a Pentax camera review at Digital Camera Review once, and I believe they called it a form of sensor bloom. Here's the review that I'm talking about:

Pentax K2000 Review
03-14-2010, 03:09 AM   #22
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QuoteOriginally posted by Tim_R Quote
Has anyone else run into this? If so, what caused it, and what can I do to ensure I don't lose critical images to this problem. Yes, I can salvage them in post processing, but quality degrades in the process.
One pertinent question, you say the images weren't consecutive, was the shooting mode consistent? Why I ask is that the scene modes will result in AWB even if you had Tungsten WB set for P,Sv, Tv, Av and M.

Cheers,
03-14-2010, 07:15 AM   #23
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All 62 pics were shot with the camera on Av mode, all with the 18-55mm kit lens. I've c hecked the exif data of all, and some of the blue tinted ones were shot within 1 minute of the previous - good - pic, or followed by a good pic less than a minute later. To conserve batteries, I turned the camera off between shots. Because it was cool out, I did NOT preview any pics during the hike. I waited until I got to the car for that, especially since in bright sunlight it is difficult to tell much about pic quality from the LCD display.

As I mentioned above in the post with the extended exif data. there are TWO entries for WB. The first shows how the camera was set. The second shows the white balance USED when the exposure was made. The camera was set for AWB, but the bad pics were processed by the camera into jpgs using tungsten WB.

Tim

03-14-2010, 07:37 AM   #24
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QuoteOriginally posted by Tim_R Quote
As I mentioned above in the post with the extended exif data. there are TWO entries for WB. The first shows how the camera was set. The second shows the white balance USED when the exposure was made. The camera was set for AWB, but the bad pics were processed by the camera into jpgs using tungsten WB.
Beats me, it's really difficult to get AWB to misbehave that much, I suspect that your camera has some strange fault. It's difficult to determine the best way to handle problems like this, I expect that it would be pretty tortuous to send it for warranty if the problem is sporadic. Good luck.
03-14-2010, 03:13 PM   #25
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QuoteOriginally posted by Tim_R Quote
...there are TWO entries for WB. The first shows how the camera was set. The second shows the white balance USED when the exposure was made. The camera was set for AWB, but the bad pics were processed by the camera into jpgs using tungsten WB.
That sounds completely normal to me.

AWB means 'Automatic White Balance' - it doesn't mean a particular WB setting. It just says that the WB mode has been set to let the camera decide WB. The second entry just shows the WB setting the AWB actually decided to use.

If you manually set the camera's WB to Tungsten, instead of telling the camera to use AWB, then the two entries would read:

(1) Tungsten
(2) Tungsten

If you set the camera's WB to AWB, the two entries could read:

(1) AWB
(2) Daylight (or Cloudy or Tungsten or Flourescent Light etc)

depending on what the camera's sensor was seeing.

No need to get the camera serviced for that.

It's like the exposure settings. You set the exposure to an AE mode, then the EXIF reports which AE mode you set and what f stop was used.
03-14-2010, 04:51 PM   #26
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QuoteOriginally posted by rawr Quote
That sounds completely normal to me.

AWB means 'Automatic White Balance' - it doesn't mean a particular WB setting. It just says that the WB mode has been set to let the camera decide WB. The second entry just shows the WB setting the AWB actually decided to use.

If you manually set the camera's WB to Tungsten, instead of telling the camera to use AWB, then the two entries would read:

(1) Tungsten
(2) Tungsten

If you set the camera's WB to AWB, the two entries could read:

(1) AWB
(2) Daylight (or Cloudy or Tungsten or Flourescent Light etc)

depending on what the camera's sensor was seeing.

No need to get the camera serviced for that.

It's like the exposure settings. You set the exposure to an AE mode, then the EXIF reports which AE mode you set and what f stop was used.
If you inspect any RAW images shot using the AWB settings you will appreciate that the colour temp/tint applied to each image is continuously variable, AWB does not select an arbitrary WB from one of the pre-selects. The posters camera is patently not operating correctly given the information that he has provided.
03-14-2010, 05:58 PM   #27
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QuoteOriginally posted by distudio Quote
If you inspect any RAW images shot using the AWB settings you will appreciate that the colour temp/tint applied to each image is continuously variable, AWB does not select an arbitrary WB from one of the pre-selects. The posters camera is patently not operating correctly given the information that he has provided.
Pls note Mark's comment above - AWB is not applied to RAW images. Hence what you see when you play with the sliders in RAW...

In operation on JPG's, AWB just applies to the image the preset WB settings from the built-in selection of WB settings the camera has - Daylight, Tungsten, Kelvin, Flash etc. AWB is not a continuously variable parameter when applied to JPG's produced in camera. I'm pretty sure of that.
03-14-2010, 07:21 PM   #28
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QuoteOriginally posted by rawr Quote
In operation on JPG's, AWB just applies to the image the preset WB settings from the built-in selection of WB settings the camera has - Daylight, Tungsten, Kelvin, Flash etc. AWB is not a continuously variable parameter when applied to JPG's produced in camera. I'm pretty sure of that.
That would explain why I only see the one setting listed in my EXIF; I'm only shooting RAW. I believe OP was shooting RAW+JPG.
04-09-2010, 08:03 AM   #29
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This reminds me of a WB problem I had w/ my friend's Olympus E-510. I took photos of a garden and the AWB switched back and forth bet/ warm and cold, so among the photos that came out some were too warm and some were too cold/blueish. In my case setting the WB manually fixed the issue, but I don't think this is normal behavior on K-x from what I know about the camera.

My K20D and K-7 never had such variance when using AWB, in fact among all the cameras I laid my hands on I think my K-7 has the best AWB performance. I hope that this won't happen on a regular basis with your K-x.
04-09-2010, 01:05 PM   #30
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Gardens are tough. A camera really can't tell the difference between a red flower in white light versus a white flower in red light. So it knds of makes its best guess, but it's likely to be off by more than it would in other settings without such brightly colored objects.
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