From a theoretical standpoint, there would still be potential for mischief when parts of the subject reflect or shadow other parts of the subject. In theory you can make the illumination perfectly uniform, but if you make the whole scene perfectly uniform you get a pretty boring picture.DQE wrote:If one had literally perfectly diffused light, would these problems still occur with some subjects (such as the one Rik has been photographically torturing - grins)?
Perhaps it's not sufficient to only perfectly diffuse the incident light, but instead one should perfectly diffuse the combination of the scene and the light source(s)? Or, would even that effort be enough to prevent these artifacts/effects?
I think so, sort of. It seems to be a good rule of thumb that you need to have good diffusion somewhere in the system. If the subject itself has a sufficiently matte surface, you can get away with directional illumination, but if the subject is shiny you need soft light.In other words, do these initial results suggest that one may have to custom-tune the lighting to match the reflection properties of the subject and background, in order to minimize the effects?
This is a promising idea. Light that fills only part of the aperture is likely to be reflection from a shiny surface, so killing specular reflections should eliminate the asymmetry that causes the warping effect.Perhaps fiddling with cross-polarization would help, although it would also create various problems and challenges of its own.
Unfortunately, this specimen is basically a black hole with a shiny surface that has an interesting shape. If I kill the reflections, I kill the image.
--Rik