Stephen - it was a bad thread. Or at least bad to start it the way I did because it would confuse people. It was the first step in a broader analysis but on its own it was not good. The idea was to take a typical ZS-type test (ie in-camera instead of wedge/tablet, shooting a target tone), refine it somewhat to remove as many variables as possible and as much camera flare as possible, and try to create/isolate a subject flare factor. Part of the purpose there was to "prove" that with a uniform target the added flare density is constant regardless of exposure, which it did. But the problem is it quickly became obvious presenting this data in graphical format (a characteristic curve) is misleading because on its own it only shows flare exists (ie a parallel shift in the curve). It does not show the effect of flare when making a single exposure of a full scale subject. As the experimenter I understood this, but it was a confusing illustration. Showing parallel curves can give the impression the effect of flare is eliminated by simply reducing exposure - the very thing I was arguing against. So I figured it was better to get rid of it. The last thing we need on APUG is more confusion.
But at least if nothing else it proved to me, with my own data, that flare density is constant in a typical ZS test, whatever the flare density is (if any), which was part of the purpose of this first step. The other interesting thing is it showed it is actually quite difficult to create a lot of flare in a test shooting a reflective target. With my limited indoor setup I was only able to get a 5 stop metered difference between white and black, and the amount of flare density was a little less than I had expected. Actually I didn't really know what to expect, but I got only 3 density points of subject flare density - although at the bottom of a H&D curve this could indeed be material.
Last edited by Michael R 1974; 02-19-2013 at 07:52 AM. Click to view previous post history.