Is this what we call noise?

Discussion in 'Photography Beginners' Forum' started by nüborn, May 30, 2010.

  1. nüborn

    nüborn Guest

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    On a 20 secs exposure at 400 ISO, I ended up with some grain but also very bright sparks randomly colored. Is this normal? Is this what we call noise?
    [​IMG]

    Now, I just saw that there some options turned on (to reduce the noise actually) in the setup of my Canon camera, would that happen to be the reason why I get these colored dots?
    Long exposure noise reduction 1:Auto
    High ISO speed noise reduction 1:On
    Highlight tone priority 0:Disable
     
  2. pbelarge

    pbelarge TPF Noob!

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    That looks like it may be dust. There is noise in the photo, take a look at the photo at 100% and you will see it more readily.
     
  3. haynchinook334

    haynchinook334 TPF Noob!

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    Looks like your lens/sensor might be dirty.
     
  4. sleist

    sleist Been spending a lot of time on here!

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    If I'm reading your mind correctly, the "grain" you are referring to is the noise.
     
  5. LaFoto

    LaFoto Just Corinna in real life Staff Member Supporting Member

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    Those dots look like dead pixels to me, more than dust. And your photo is not noisy (translated into film-lingo: it has no grain). Noise in the world of digital photography is what grain is in the world of film photography.
     
  6. Phranquey

    Phranquey TPF Noob!

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    :thumbup:

    Shoot a bright white background, and any dust on your sensor becomes clearly evident as little grey blurs... but usually aren't seen on darker backgrounds like this. Those little "hotspots", particularly the ones on the right, are burned out pixels in your sensor.
     
  7. nüborn

    nüborn Guest

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    Thanks folks. Turned out that they are "hot pixels". Can only see them in very very long exposures.
     
  8. Derrel

    Derrel Mr. Rain Cloud

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    Those are stuck-on pixels or "hot pixels", which often show up in long exposures.
     
  9. ghache

    ghache TPF Noob!

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    hot pixels sucks!
     
  10. Dao

    Dao No longer a newbie, moving up!

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    Agree. Looks like Hot pixels
     
  11. Big Mike

    Big Mike I am Big, I am Mike Staff Member Supporting Member

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