Odd Black and White Grain

Discussion in 'Digital Discussion & Q&A' started by taracor, Mar 14, 2010.

  1. taracor

    taracor TPF Noob!

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    I've noticed that very often when I take photos with my D50 and convert them to black and white, they get this weird grain, and I can't figure out what is causing it. Here is an example of what I'm talking about, though it might be kind of small. I can upload a larger version if that would be helpful.


    [​IMG]


    As you can see, it's mostly in the shadowy areas, like on the corner of the back hoe (excavator?) and in the clouds, particularly in the top left.

    These were taken in color as Fine quality Jpegs and then converted to BW via the channel mixer function in GIMP. It was a pretty gray and nasty day. Any ideas as to the cause and possible solutions?
     
  2. KmH

    KmH Helping photographers learn to fish Supporting Member

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    You posted a pretty small image. I'm having trouble seeing your problemm areas even on a 24" monitor.

    Since you're capturing as JPEGs and they only have an 8-bit color depth I'd just about be willng to bet that after converting to B&W in your freeware, you're seeing posterization.
     
  3. taracor

    taracor TPF Noob!

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    Yep, you're right, it's posterization. I tried shooting in RAW today, and it worked a little better, though there is still a little bit. What can I do to minimize this? You mentioned the fact that I'm using freeware. If I were to cave and purchase lightroom or something, would this help?
     

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