Re: Sony announce A7rIII, 400/2.8 and 24-105/4 today
Let's also do a brief comparison to the Nikon D850. These both look like very good and very competitive cameras. They both have very similar sensors and similar shooting speed. Forty two vs 46 mpix and 10 vs. 9 fps (the D850 needs the grip to go to 9, however) don't seem like huge differentiators. So in resolution and speed they are about equal.
The Nikon has an excellent AF system borrowed from Nikon's highest level of pro cameras, and with DSLR you literally can borrow the AF system as it is a separate system. We don't know about the A7r III, but it will have improved AF. Will it measure up to the D850? We will see. I am sure Sony pulled out all the stops to try to get to that level, but it might take another generation of mirrorless cameras to get there. Keep in mind, however, that having a separate AF module presents its own challenges and that is potential concern for a Nikon owner. That separate AF module means the sensor and the AF module have to be carefully aligned and they often aren't and that often depends on the lens meaning that AF micro calibration is needed for each lens and this often results in less than optimum results especially with zooms. So both systems will have the advantages and challenges, but I think a good guess is that Sony will have more accurate AF that covers more of the frame, but the Nikon will have a bit faster AF that tracks a bit better. So, on AF they are different and some will prefer one system to the other but I don't think we will be able to declare on universally better, that is unless Sony really screwed up in its implementation of AF with the A7r III, which I highly doubt.
Dynamic range will also be an interesting comparison The D850 has dynamic range about equal to the D810, which is excellent. The A7r III claims to have a stop better dynamic range than the A7r III which would actually put it just a bit better than the Nikon D850. But, how did Sony achieve this additional dynamic range? Is it always available at low ISO or are some conditions necessary to achieve it? In any events both cameras will be great with DR, but it will be interesting to see which is actually better.
How about high ISO noise? The D850 actually is a bit better at high ISO than the D810 and about matches the A7r II, it looks like the A7r III will perform a lot like A7r II. So, this again looks like a draw.
How about color? This is going to be subjective and I am betting that fans of both think their camera has better color. Measurement of color at places like DXO will probably measure them as being pretty similar. It is hard for me to see too much of an advantage either way, but this is personal and will matter to some. Pixel shift should produce a color advantage for the A7r III in those cases when it can be used, but its uses are limited to pretty much completely static scenes.
So, I don't think we are going to see huge differentiators between these two cameras on their output and performance. AF is probably the place that we see that most. Where we will see difference is in preferences for an OVF vs. and EVF, for preferences in ergonomics and menus, for preferences in size and battery life, and in the importance of video for your shooting (here I think the Sony has a clear advantage).
So, in my view these two camera are great competitors and they are great all around cameras. Reasonable people will pick either camera, but I also think that means Sony did a great job with this upgrade, because I think Nikon did a great job with the D850.
Oct 25, 2017 at 09:45 AM
Previous versions of Steve Spencer's message #14228989 « Pre-orders open! Sony A7R III and FE 24-105mm f/4 OSS lens! »
