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Digital camera (D70) & Moire patterning

Discussion in 'Photography Forums' started by johnmoyle, Jul 16, 2004.

  1. johnmoyle

    johnmoyle
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    I have just purchased a Nikon D70 - FANTASTIC!
    However if I try to photograph photos in books journals etc I get bad moire patterning which does not happen with old fashioned photography.
    Any way around this?
     
  2. apreading

    apreading
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    In a word - No! (sorry)

    Some cameras have less of a problem due to the use of a stronger anti-aliasing filter (look up NyQuist if you want the reasons) in front of the sensor, however the tradeoff is sharpness. Basically this softens the image before the bayer interpolation on the sensor to bring the frequency down below Nyquist and avoid Moire. The D70 went for a weaker AA filter to boost sharpness and supposedly does some anti-aliasing in software, but it is hotly debated how effective software can be after the image capture and generally the conclusion is 'not very'. Be thankful - the Kodak cameras dont have an AA filter at all!
     
  3. woody67

    woody67
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    Buy a flat bed scanner, which will have a scan setting to stop this

    You'll also get a much better copy of the image
     
  4. Peakoverload

    Peakoverload
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    If what apreading is correct wouldnt shooting in RAW bypass this and so get rid of the moir?
     
  5. woody67

    woody67
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    I thought this was an issue with the sensor chip, and not the file format?
     
  6. apreading

    apreading
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    woody is right - the moire is still captured by the sensor. using RAW does allow for more powerful software techniques to do their best to reduce it as it can spend longer and have more processing power to do the job - but this only works to a limited degree, and only if you have very good software. Kodak and Sigma have put alot of effort into this as they dont use AA filters at all to boost sharpness (plus at the Kodak resolution Nyquist is alot higher and moire is reduced anyway) but Moire is still a problem so they cant fix it properly through software alone.
     
  7. Peakoverload

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    Ahh I understand now.
     

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