A&P Image Calibration to Reduce Noise

Discussion in 'Lifestyle' started by psykosis, Jun 3, 2008.

  1. psykosis

    psykosis Go placidly amid the noise and the haste

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    playing around with StumbleUpon, and found this. It's a bit technical, and kinda long, so I'll have to read through it a couple times to absorb it all, but seems like a good idea at first glance.

    http://photo.net/learn/dark_noise/
     
  2. Jonny Chimpo

    Jonny Chimpo OT Supporter

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    Seems like a solid theory at first glance, but after a very quick test it appears to have little effect on short exposures with my 40D. There is a difference but it's negligible. NR in the RAW conversion workflow would be more effective than these extra steps.

    I tried it out at 50mm, f/1.8, 1/3sec, handheld. YMMV, but it doesn't seem worth the effort unless you are shooting MUCH longer exposures with much more noise. It might also apply more to older cameras that suffer from more noise issues.

    :dunno:

    Oh, and that writeup was about 10,000% longer than it needed to be.

    Cliffs:
    1. Use RAW
    2. Take image in manual exposure mode
    3. Switch lens to MF
    4. Put on lens cap and put your thumb over the VF and shoot a second frame
    5. Open first image in Photoshop with no adjustments
    6. Open second image in PS
    7. Paste second image as a new layer on image 1
    8. Change blending mode to difference
    9. ????
    10. profit

    Time for another beer....
     
  3. Yoritomo

    Yoritomo dad's jar chimer

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    Just a note. The d40 and all the Nikon cameras made after it do this when you turn long exposure NR on. It's why most people turn it off unless they're doing a long exposure.
     

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