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Old Sep 10, 2008, 12:59 AM   #21
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Jim,

Yes, the first lens cap picture I posted was at ISO 400. I can see that now and I posted that picture in the fogginess of waking up. I took a lens cap picture again, ISO 100, "Long exp. NR" On, "High ISO NR" Off. I "see" three troublesome areas (see attachment):

1653, 492 (this is persistent)
2189, 1042
1438, 2114

I think I read your post correctly, so I flipped into manual mode and starting shooting lens caps (manual focus) images from 1/60" down, f5.6. 1653, 492 did not start showing obviously until 4".

I am undecided now. I really like the a200 and for a (re)entry into dSLRs, it's a decent start. Plus, as I said, I can use all my other Maxxum lenses. I have four more days to play with the camera and decide whether I should return it and risk getting another with different hot pixels, or other worrisome points.

My wife pointed out to me again this evening that I'm the type of person, that once I find something wrong with a particular item, I will fixate on that problem until I burst. I thought I had gotten better. Obviously not.

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Old Sep 10, 2008, 11:46 AM   #22
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Something doesn't seem quite right with your results. You should not have a pixel that bright that's in the same place in multiple images with long exposure NR enabled, unless it's not working.

That's why I keep asking if you're sure about that part. With it enabled, the camera is taking two photos, so it takes twice as long to process them.

For example, if you take a 6 second exposure, the camera should be taking *another* 6 second exposure with the shutter closed to use as a black frame to perform the noise reduction. It works by looking at the black frame and finding the locations of any hot pixels (since those are the only ones that would show up in a dark frame exposure with the shutter closed). Then, it removes those pixels from the actual exposure, since they're usually going to be in the same place on both images taken at roughly the same time, since camera temperature should be close, as will be the settings for ISO speed and shutter speed used for the real exposure and the extra dark frame exposure the camera takes with long exposure NR enabled.

Again, make sure you've got it enabled for your tests.

I'd probably reset the camera back to factory defaults, just to make sure another setting isn't causing a conflict with it.

You'll see a menu choice labeled "Rec Mode Reset" to do that on the same screen with the NR settings.

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Old Sep 10, 2008, 12:06 PM   #23
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If resetting it doesn't get the NR to work, I'd try shooting with a little light in the image, in case the camera is smart enough to realize that there is no recordable detail (which it could determine since the EXIF is recording brightness level) and not doing it's normal long exposure NR. Most people don't shoot the inside of lens caps. ;-)

You should be able to tell if it's working or not (if it is, the camera will take twice as long because it's taking a second dark frame image to use for the pixel remap).

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Old Sep 10, 2008, 12:36 PM   #24
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Jim,

Thank you for your patience with me.

I did the "Rec Mode Reset" as you suggested. I took a 10 second lens cap at ISO 100 with "Long exp. NR" on. After the 10 shutter stays open for 10 seconds, the shutter closes, the camera display shows "Processing..." for 10 seconds, then saves the image. Hello familiar hot pixels centered around 1653, 492. When I set "Long exp. NR" off and do the same 10 second exposure, the shutter stays open for 10 seconds, closes and saves the image. Same hot pixels at 1653, 492, plus a few more scattered about. I even did a couple of time advances, as suggested in other forums, to force the camera to do a remap. Nothing seems to help.

When shooting "regular" subject material, this pixel is either very noticeable or not at all. It seems that when the area around the pixel is green in color, it's more pronounced. This is consuming my every waking thought. Obsessive compulsive people should not buy digital cameras.

I had decided last night that I could live with this, but today, I'm not sure. I should not have to deal with this on a brand new camera. On the same note, I feel that I have no guarantee that I will not have to deal with this on any dSLR I purchase, regardless of the manufacturer. I'm tempted to return it and drop the idea of having a dSLR. I'm being melodramatic because I quite rather enjoy using a dSLR again. Now I'm just gunshy.

Every other digital camera I have owned has had problematic pixels (a Sony Mavica, a Sony DSC-P30 and a Sony DSC-P73 (hello Sony fanboy)), but the issues took time to develop (well after a year of use) and have seem to go away with remapping. To deal with this from the get go bothers me.

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Old Sep 10, 2008, 12:45 PM   #25
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JimC wrote:
Quote:
If resetting it doesn't get the NR to work, I'd try shooting with a little light in the image, in case the camera is smart enough to realize that there is no recordable detail (which it could determine since the EXIF is recording brightness level) and not doing it's normal long exposure NR. Most people don't shoot the inside of lens caps. ;-)

You should be able to tell if it's working or not (if it is, the camera will take twice as long because it's taking a second dark frame image to use for the pixel remap).
I had done just that last night. I set the camera on tripod and took a picture of the house outside at night. Lots of nice detail of the house lights glowing. Plus some stars. Plus 1653, 492. It's hit or miss with this pixel. On some pictures where I thought for sure it would show up, darkened shadows of tree leaves against a late afternoon sun, nothing. A tripoded picture of the canopy of trees down the street at dusk, very noticeable. I can't see it in any flash pictures I take, which might be a good thing.

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Old Sep 10, 2008, 2:21 PM   #26
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If it's brand new, I'd get the vendor to swap it out for you if it were my camera and that one pixel was showing up in images with any properly exposed subjects in them.

I'm still wondering why the long exposure NR wouldn't be seeing it though (as it appears to be bright enough that it should be mapping it out). If it's showing up consistently in the same spot, the long exposure NR should be seeing it. As for the date remapping, it's only going to remap pixels that might be bright enough to show up at more commonly used shutter speeds faster than 1 second. You don't want it mapping out pixels that are only going to be hot with longer exposures (as the vast majority of photos are taken at shutter speeds much faster than 1 second). ;-)

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Old Sep 12, 2008, 1:18 PM   #27
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I've taken close to 400 pictures with this camera and I like the a200 for so many reasons. The menuing is decent, lots of options are one button press away, it mounts as a mass storage device and it takes decent pictures. Except for this hot pixel. Yes, the majority of my pictures are at shutter speeds well beyond one second, but if I look, and I *will* look, at the spot where the hot pixel is, I can see the camera trying to deal with it and often producing a "sparkle" effect around it where otherwise the pixels should be smoothly graduated. I do, however, take quite a few pictures with cameras tripoded at low level lighting conditions because I like ambient light. The pixel shows up very distinctly in these shots and does require cloning out.

The hot pixel was showing up in 1/8 second, 1/2 second, 0.6 second exposures at ISO 100.

My normal work flow with pictures is to dump them from the camera and that's it. I might resize a few for posting on the web, but the good majority of pictures are left as negatives for me to look at months later. I expect to have these pixel issues with the camera AFTER I have used it for some time, not out of the box.

I am returning the camera this evening. I likely will not get another from this vendor as I am on camera two from them. I like and want the a200. If they will provide me with another camera and a period of time to test it out, I will be more than happy, but I doubt this to be the case.

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Old Sep 12, 2008, 7:36 PM   #28
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You could always send it to Sony and let them fix it, too. They probably have service software that could get rid of a hot pixel that the normal remapping and long exposure NR isn't taking out for some odd reason.

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