the last word

In preparing the image of the Don Worth succulent for printing, I’ve discovered  a great many motion artifacts. Some of them, like this one caused by an insect crawling across one of the leaves:     need special attention. However, there are many artifacts caused by motion of the leaves that could benefit from an… [Read More]

Yesterday I posted raw histograms from the Nikon D810 and D800E that showed that Nikon performed aggressive black-level subtraction in the D800E files, while there was very little clipping of the left side of the histogram in most cases with the D810. The conventional quick way to measure dark-field noise is to compute the ratio… [Read More]

People have asked for comparisons between the dynamic range of the D810 and its immediate predecessors. I don’t have a D800 at my disposal, but I do have access to a D800E, and I thought I’d do some testing. But first, a little discussion of dynamic range.  The dynamic range of an imaging system is… [Read More]

About a year ago, I identified a problem with the Leica M240. There is a clipping of very low raw values and a non-linearity near zero for those values that leads to problems in the shadows of  images pushed in post. Since, for most lighting conditions and subjects, the green channel is the brightest one,… [Read More]

A few weeks back, I did a series of dark-field exposures with the Sony alpha 7S (a7S) at all available ISO settings. After some processing, I produced this graph: There are two places in the curve where sudden — and unexpected, at least by me — drops occur as the ISO is increased. The first… [Read More]