Dead pixels?

Discussion in 'Photography Beginners' Forum' started by bazooka, Feb 13, 2010.

  1. bazooka

    bazooka No longer a newbie, moving up!

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    I was taking some shots tonight and upon looking at them at 100%, I noticed a white pixel on my black dog. Then upon further inspection, I noticed another. These shots are RAW btw. So I took a shot with the lens cap on and counted about 20 pixels across the shot that are either white, red, blue, or green. Is this normal or is this a serious problem with my sensor? Upon converting to a compressed format, they go away as expected.

    The camera is a 40D that I purchased used.
     
  2. bazooka

    bazooka No longer a newbie, moving up!

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    I suppose I should have google'd it first. :D It appears to be normal. It just sucks that in every dark photo I do, I'm going to have to do lots of pixel fixing if I don't compress.
     
  3. cletusjermal

    cletusjermal TPF Noob!

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    I was gonna ask the same question. Hopefully it is normal. I just bought mine about 2 weeks ago and noticed the same thing on mine. I took some pics tonight and noticed some red pixels in the pic. I was shooting in RAW and JPEG and had them in both the RAW and compressed. Here is what mine looked like. Kinda hard to see on here but oh well.
    [​IMG]
     
  4. bazooka

    bazooka No longer a newbie, moving up!

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    Take a RAW shot with your lens cap on and then view it at full size, I think you'll find that you have a lot more. Of course, now it's all I'm going to think about so on the other hand, maybe you shouldn't. :)

    It also seems related to ISO as well... although most of my hot pixels stayed in place regardless of ISO, some faded so they weren't quite obvious.
     
  5. Overread

    Overread has a hat around here somewhere Staff Member Supporting Member

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    Hmm I know dead pixels is a factor to consider when doing slow shutter speed nighttime photography (ie going into minute and longer exposures) but I thought that general darker shots (taken within more normal shutter speeds) would not be affected?

    Of course if one does a lot of nighttime photography those dead pixels will come to affect the main shots as well.
     
  6. bazooka

    bazooka No longer a newbie, moving up!

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    Based on the couple of articles I read, it's normal for even the most expensive dslr's. However, I did only try to change the ISO.... the shutter speed for the shots was 1-2 seconds so perhaps a faster shutter speed would help. I shall continue experimentation. :)
     

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