Today I turn the read noise analysis tools developed over the past couple of weeks to a new camera, the Leica M240. The M240 is one of those cameras that subtracts out the black point before it writes the raw file, so we won’t get a clear picture of the read noise from a dark-field… [Read More]

Several people have told me that they thought that the read noise patterns from CCD sensors were less objectionable than the patterns from CMOS ones. I have an old Hasselblad, the H2D-39, and I performed an analysis. There’s a problem with looking at the read noise of this camera. Unlike the first two cameras I… [Read More]

The Sony a7S switches to high-conversion-gain mode as the ISO dial is moved from 1600 to 2000. Thus ISO 3200 is the first whole f-stop ISO to get the benefit of increased conversion gain. In this post, I’ll show ISO 3200 dark-field images filtered with the same set of kernels as the ISO 100 images… [Read More]

In the previous post, I showed plots of data derived from a series of Sony a7S images of the back of a lens cap at various ISO settings. Now I’d like to show some of the filtered images themselves. Since there are 540 images represented in the plots (10 ISOs, 18 kernel sizes, and 3… [Read More]

Today, I’ll apply the same read noise analysis approach of the last few posts to a new camera, the Sony alpha 7S. The a7S has the — unique in my testing — ability to change its conversion gain as a function if the ISO setting. The conversion gain jumps when the ISO dial is turned… [Read More]