Archives for December 2013

Many people look at graphs like those in the last post, nod their heads, but don’t really believe the results. If you’re one of those people, read on. You’ll have actual photographs to look at. I went with my favorite subject for noise testing, my bookcase. Usually, I use a 35mm lens on a full… [Read More]

I’m going to repeat some of the explanatory material from my Leica M240 review. Those of you who are familiar with my analytical techniques, feel free to skim this post. With the noise floor and self-heating testing out of the way, we’re ready to tackle the question, “Is the a7R ISOless?” If that question makes… [Read More]

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]