Archives for 2013

I took the data from the preceding post, and analyzed the chromaticity errors, which I defined at the square root of the sum of the difference between the a* and b* values of the unpushed and the pushed image. Here’s what I got, plotted, as before, against, the luminance of the test patches: Except for… [Read More]

In a Leica forum, a poster advanced the thesis that pushing in post increases contrast, and posted some images made with varying f-stops as evidence. I was worried about the effect of flare, which varies with f-stop in many lenses. And — you know me — I wanted something quantitative. I thought I’d do some… [Read More]

As we saw here, modeling the M240 as a normal camera with a slight negative offset helped explain the off noise floor characteristics, but didn’t provide a close match to the way the actual camera performs. It turns out that negative offsets can model the dark tone errors quite well. Here’s what the green channel… [Read More]

One thing to be ruled out on the M240 testing that I reported on here is that there might be something special about the green channel, where I got all my data. It’s a highly unlikely possibility, since the only thing that ought to be special about the green pixels is that they happen to… [Read More]

I performed the same test as I used in the last two posts on a Leica M9. Here are the results: The results, while not quite up to the exemplary standard set by the Nikon D4, are substantially better than the Leica M240 graphs. There is something strange, however. Like the M240, the M9 errors… [Read More]