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Old May 7, 2007, 10:21 PM   #1
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Well I'm new to the dslr scene.. I used to love taking pictures with my old pentak k1000 and decided to try out something new.. but I purchased 2 cameras so far and braught the first one back and just opened a new e-500 2 lens kit... first camera was a pentax k100 nice I liked it but it was i discounted display model which seemed to have what looked like dead pixels it the image it self "anyone wants a sample i can send one".. this didn't look like dust. So I picked up this camera the e-500 .. i've taken about 10 pic's, and have found what seems to be 4 dead pixels.. Is this common or am i doing something wrong? dust maybe? they are 4 spots uniform in size and shape 2 red one blue and one light green/grey.. as I've said i can send samples to anyone who'd like to give an opinion... Thanks
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Old May 8, 2007, 1:51 PM   #2
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Please attach some pictures so we can see the pixels.
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Old May 8, 2007, 4:51 PM   #3
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http://www.mediamax.com/vaq2/Links/AF83D8C0AE

Here they are for download
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Old May 8, 2007, 10:49 PM   #4
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Those are not dead pixels, they are hot pixels. The Exif data shows that you took the photo with a 2 second shutter speed at f3.5. At slower exposures it is not uncommon to have a few hot pixels show up. 4 hot pixels out of 8 million is not to bad although on my 30D I do not have any hot pixels showing up until I hit the 20 second shutter speed. I doubt Olympus would consider this abnormal, but you could always contact them and see.
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Old May 8, 2007, 11:36 PM   #5
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Many higher end camera have a calibration function which maps the output of individual pixel and makes the appropriate gain adjustments. Does yours?
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Old May 8, 2007, 11:54 PM   #6
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well in the setup menu there is an option called pixel mapping... I guess this might be what your talking about.. But i'll read the manual first to make sure.. Thanks
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Old May 9, 2007, 5:06 AM   #7
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Vaq2 wrote:
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well in the setup menu there is an option called pixel mapping... I guess this might be what your talking about.. But i'll read the manual first to make sure.. Thanks
Olympus is about the only manufacturer that provides convenient in-camera pixel mapping. With other manufacturers, you have to take the camera back to the service center to have the mapping done. As has been pointed out, though, pixel mapping, is for truly dead pixels, those that stay on/off in the same place in every photograph, no matter the exposure setting.
On the other hand, if you're getting merely "hot" pixels that vary in place from photograph to photograph (usually occurring in long exposures when the sensor heats up), you should use the NR function in the camera's menu. That function operates using "dark frame subtraction" in which a non-exposed frame is recorded immediately after the actual exposure. The two frames are compared and any hot pixels found in the "dark frame" are subtracted from the actual exposure. I don't know about the E-500, but on my E-300, dark frame subtraction only works on exposures of 4 seconds or longer.



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Old May 9, 2007, 9:09 AM   #8
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Kodak includes pixel calibration on the P series cameras.
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