the last word

Earlier, we saw indications that the Sony a7RII was doing spatial filtering of raw images at ISO 32000 and above. In such situations, I find it instructive to look at spatial frequency graphs. Assuming that some of you do as well, here is a graph of the horizontal and vertical spectra of a 1000×1000 pixel… [Read More]

Some of you asked for this: The red, green, and blue raw channels are all on top of each other. The D810 curve is the one that starts at ISO 32 and goes to ISO 50K. The a7RII  curve is the one that starts at ISO 50 and goes to ISO 100K. These curves are… [Read More]

I set the shutter to single shot, the ISO to 6400, turned off all the noise reduction options that the a7RII exposes to the user, and made a series of dark-field exposures at shutter speeds in 1/3 stop intervals from 1/2000 until boredom set in. Here’s the way the read noise varied: You can see… [Read More]

Before I get too far into testing a camera, I do a series of exposures calculated to see if there are self-heating effects that might skew my test results. Since many of my tests involve making series of sequential exposures that are later subjected to statistical analysis, material self heating can force me to slow… [Read More]

I have seen claims that the a7RII has lower precision with EFCS on than it does with it off. That makes no sense to me, and the a7, a7S, and a7II don’t do that.  Since it’s pretty easy to check, I ran read noise curves both ways: The curves are virtually identical. While I was… [Read More]