I conducted an AF test on the A7M2 that I frequently try on new cameras to see how well they AF. It is a simple test and surprisingly many cameras show themselves to be slow doing the test. Until today I hadn't thought of a way to do the same test for low light performance.
The test:
1. I run the electronic stop watch
2. Every 5 seconds I fully depress the shutter which forces a full focus action (no 1/2 presses)
3. I do this until 50 seconds have elapsed (10 shots)
4. Look at each image, it should be in focus and add the times and divide by 10 to obtain the average.
With a bright screen display (my iMac screen brightness set to mid way), the 28-70mm FE kit lens set to 50mm and f4.5, I obtained the following averages:
A7M2 = 227ms
A6000 = 264ms (This was a surprise to me, I expected the A6000 to beat the A72)
Both cameras are set to DMF and flexible spot AF (m)
To simulate a low light situation it occurred to me that I could dim the display to the point I was shooting at ISO 4000 with the same lens at 50mm and f5.6
Here are the results:
A7M2 = 371.3ms
A6000 = 426.3ms
Pretty impressive times and response under both conditions. I have seen the A7M2 quickly obtain focus in light levels that the auto ISO selected 12,500 at 50mm f4.5. The A7 would have been hunting all over the place.
Any thoughts on the test methodology and how does this compare to what others are finding?
Also ran another test with the 10-18mm lens:
Ran the test with bright screen and A6000 using e 10-18mm at 18mm f4, ISO 200 light level and the results were: 229.4ms
Same setup on the A7M2 and the results were 202.4ms
This camera's AF is deceptively fast!