the last word

Does anyone remember the noise floor that was way too low in this post, the one in which I did the self-heating testing at ¼ second and ISO 100? And did anyone notice that the ¼ second, ISO 100 noise floor in the preceding post was much higher? How can that be? Aren’t all exposures… [Read More]

I investigated the odd behavior of the a7R noise floor versus ISO uncovered in the last post. I made a series of 16 dark exposures for each data point at shutter speeds of 1 second, ¼ second, 1/15 second, 1/60 second, and 1/250 second, at ISOs of 100, 200, 400, and 800. I didn’t go… [Read More]

The next step is to look at the way the noise floor varies with ISO settings. I used 1/30 of a second for this test, made 16 exposures for each data point, and the results were surprising. Here’s the average value of the noise floor in the central 90% of the image vs ISO: And… [Read More]

I mounted a Leica 135mm f/3.4 APO Telyt on the a7R, mounted the camera on the tripod head with a generic RRS plate (RRS does not at present have custom plates for the a7 or a7R), and made an image (details in the preceding post). Here it is with as 6x expansion vertically and 2x… [Read More]