It struck in me in reading what appears to be a pre-release version of an upcoming camera press release that the camera companies themselves are verifying what I've been saying all along. (In case you worry that I'm quoting something from what might be fake, I went back and looked at a bunch of previous camera announcements and found variations on the same thing.)
The critical words are "we've improved the autofocus system."
Now, if we're to believe the fan boy claims, some camera brands have been focusing "perfectly" for quite some time (I can document this claim going back to 2014 in mirrorless). Gee, if the cameras were focusing perfectly, why would we need any improvements to autofocus? ;~)
A great autofocus system has the following attributes: speed, accuracy, consistency, persistence, controllability. These days we have to add a component for subject recognition, but subject recognition also requires speed, accuracy, consistency, persistence, and controllability.
Most folk writing about (or shouting about ;~) how great their autofocus system is are really saying "[this autofocus system] produces better results than I've been able to achieve before." That might be because:
- It focuses faster than they were previously capable of.
- It is more accurate in focusing than they have been previously.
- It is more consistently in [or close to] focus than they've previously achieved.
- It is more persistent about putting the focus plane in the correct spot than they've achieved before.
- It allows them to better control where focus is put and when it's changed.
It's that last bullet I look to first, because I know that autofocus systems are already mostly fast, accurate, consistent, and persistent. Any improvement in those things is, of course, welcome, but I use that last bulleted thing to get even more out of them.
Do we all want more? Of course. We're greedy.
Do we need more? Uh, I've been doing in focus sports and wildlife photography for decades that gets published, so I'm not so sure about that. Every major change in autofocus systems—and every camera maker has gone through a few—means I have to take time and effort to learn what's new, how they perform, and how I'm going to get nuanced control over them.
It's that last point that is really driving the hyperbole about how great the latest focus system is. Why? Because the vocal user base is basically saying the new is doing better than the old without them having to invest any time and effort.
Still, even well-regarded Web sites sometimes add their weight to the "it just focuses" arguments that are all over the Internet. Take, for example, dpreview's recent Sony A6700 review, where they say that the subject tracking "passes this test with flying colors." I'm not sure what colors that fly have to do with focus, but look carefully at the images they supplied: the focus is consistently on the brim of the bike rider's cap, not his eyes. There's a big difference between (perhaps) usable focus and perfect focus. Apparently dpreview is satisfied with the A6700's results. I wouldn't be. You shouldn't be.
