A BEHIND THE SCENES LOOK AT RAW FILES, ISO, NOISE & HISTOGRAMS

At our January 24 Technical Series meeting we were once again treated to an extremely informative presentation by a BCA Photo Group member. Mike Milicia is an accomplished nature photographer, specializing in birds. He lectures and runs workshops quite frequently and we are fortunate to have him share his expertise with us.

It is easy to give some simple guidelines (see below) for taking images in such a way that you can get the most out of them in post-processing without sacrificing quality. But the guidelines are so much more powerful when you know WHY they exist. Mike gave an overview (abbreviated from his day-long seminars) of what is going on behind the scenes in digital image capture. He made clear through explanation, diagrams, and analogy how the physics, optics, and electronics of light capture all have implications for choices you can make to maximize usable information while minimizing noise. RAW capture mode preserves the data right out of the camera sensor, giving you freedom to make adjustments after the fact. In contrast, jpeg images have already had the manufacturer's image processing algorithms applied - and with no going back.

Here are some of those guidelines:

  • Shoot RAW
  • Expose to the right (ETTR) with lowest feasible ISO
  • RGB (rather than luminosity) histogram is the best way to evaluate exposure

You can always do something because you're told, but it's so much nicer to do something because you understand. Mike helped us understand.

And you should definitely check out Mike's web site to read more about him, see many of his incredible images, and keep tabs on his speaking engagements and workshops.