Optimizing Exposure

Regrettably, this welcome does not include camera makers. They are still making all of their cameras, even the most expensive pro models, with 19th Century exposure techniques.

Since the introduction of CMOS sensor equipped cameras with Live View capability cameras have had the ability to analyse the image being shot in real time. That’s what your rear LCD histogram is all about in Live View. It is a real-time analysis of the image, displaying where on the tonal scale every pixel being captured is to be found.

This information could easily be used by the camera to automatically calculate and set the absolutely optimum exposure for any and every scene. This would be with the brightest (non-specular) part of the image placed just below clipping. The rest of the tonalities would then fall where they may, but would be most appropriately recorded, with the largest possible range of tonal values, widest possible dynamic range, and with the lowest possible noise. …

Because the camera knows how much additional exposure is being applied above the usual “average” exposure, it would be trivial for it to generate a rear LCD preview that appeared “normal”, and similarly a simultaneous JPG could easily be produced that also looked “normal”. Indeed the entire process could be made invisible to the photographer, except that every shot taken would have about a half stop to three stops better dynamic range and consequently lower noise.

Very good points. I wonder if there is some reason camera’s aren’t doing this already that “expose right” enthusiasts just haven’t thought of? Though as sensors get better and better at seeing in the dark you could argue this trick becomes less and less necessary to know.