Archives for 2014

Here are the images from the preceding post. As usual in this read noise analysis series, they have been scaled into the range [0,1],  have had a gamma curve of 2.2 applied , been res’d down to 640×480, and JPEG’d. First at ISO 100 with no filtering: Hot pixels dominate the normalization, driving the typical… [Read More]

Next up for read noise analysis is the Nikon D800E. Unlike the D810, the D800E and the D800 subtract out the black point before they write the raw file, so we won’t get a crystal clear picture of the read noise from a dark-field exposure, but, as we saw with the Leica M240 yesterday, we… [Read More]

Here’s the ISO 200 unfiltered dark-field image. Like all the images in this post, the images have been scaled into the range [0,1],  have had a gamma curve of 2.2 applied , been res’d down to 640×480, and JPEG’d. There are hot pixels that darken the average value of the image. With 36-pixel kernels of… [Read More]

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]