Works great except 1 fatal flaw: AF inconsistency
March 12, 2015
I really want to like this camera. In addition to the camera and kit lens, I also have the 55mm F/1.8, 16-35mm F/4, and 70-200mm F/4 lenses. I like the color and contrast of these lenses. The camera is light and has a lot of useful features. However, there is one fatal flaw: the auto focus is inconsistent and inaccurate at times.
I have contacted Sony support and they escalated the issue to Level II support. A few days later, I received a phone call from them at 7am in the morning and left me a voice mail. He asked me to write down my issues in email and sent to them. So I did. But I still have not heard back from them.
Let me state my AF issue here. Some of my photos turn out slightly blurry. I have been trying to figure out how to improve it for a few months. Then I did the following experiments and believe that Sony A7II's AF is not accurate and inconsistent under certain conditions:
The experiment is as follows. Use the 55mm F/1.8 lens and set the camera at AF-S, aperture priority, center focus, and auto ISO. Try to use the AF function to lock the focus with aperture at F/1.8. Then try again at F/22. F/22 would take longer to focus, which one would think is fine.
Then please switch to AF-C. This will allows the camera to continuously focus on the subject. Try to focus with aperture at F/1.8 and F/22 again. You will find that the camera cannot lock the focus at F/22, or take much longer time to lock than AF-S. It also appears to me that the AF-C with F/22 does not lock the focus and it simply times out. This indicates that AF-S does not always give you the accurate focus you need.
I can demonstrate the AF problem consistently. Depending on the lighting condition, it shows as early as F/4.0. Mirrorless camera has come a long way. But I am very disappointed that the single most important function, auto focus, is so poor.... Read More