Archives for August 2015

In yesterday’s post, I talked about a situation that the Sony a7RII autofocus didn’t handle very well. Actually, as I said then, I think the camera’s autofocus is probably doing fairly well, but the combination of a slowish autofocusing lens (compared to some moderately rapid to breathtakingly rapid Nikon lenses) and EVF lag and blackout… [Read More]

I have tested the accuracy of the Sony a7RII autofocus for static subjects; the results were impressive. I have used the camera for many actual photographic people shots. On the whole, the autofocus systems (I say systems, because there are a dizzying number of modes and sub-modes) have performed their task with remarkable flexibility and… [Read More]

There has been a little speculation that the increase in noise observed in the ISO 100 long exposure noise reduction (LENR) images in yesterday’s post might be wholly or in part the result of the a7RII’s dropping into 12-bit precision when LENR is active. Fortunately, there’s a way to test that. Yesterday’s exposures were 30… [Read More]

Yesterday we saw that the Sony a7RII long exposure noise reduction (LENR, aka dark-frame subtraction) is applied at shutter speeds so short that it hurts the engineering dynamic range of the image. That experiment was performed at ISO 3200. It just didn’t seem right that the Sony engineers would do something like that. To be… [Read More]

We saw in the previous post that the long exposure noise reduction (LENR) option in the Sony a7RII reduced the precision from 13 to 12 bits. We have previously seen that some 12-bit modes bring spatial filtering to the a7RII. Is LENR one of them? Here’s the spectrum of a 1000×1000 sample from the center… [Read More]