Originally posted by Digitalis While it is a nice idea to think that our shiny new cameras/lenses aren't at fault when the AF stuffs up - we have to also consider the possibility that when both are calibrated and corrected to the point where nothing could possibly go wrong, and it does: there must be an third possibility - user error. When absolute precision needs to be achieved, the human element is invariably what makes things go pear shaped.
This would be a very, very bad idea. It would be making unsupportable claims about lens performance, ignoring there always will be statistical outliers. With the majority of cameras I use*, I focus manually. Because at least I know where the blame lies in the event of mis-focusing.
* In truth: in the confines of the studio, having a camera with the worlds fastest AF isn't going to make for a more compelling photograph when you're taking photos of steaming hot ramen noodles in a bowl. I do use AF some of the time for moving subjects, I don't fully rely on it. There are literally thousands of examples of good sports and action photographs that were taken without the modern convenience of Auto-focus. I'm not saying my way of working is the best: each to his own. But it is a technical choice I make.
This is what I found out for myself this year. I decided to stop using AF entirely and master MF for all my lenses, even on jobs/events! I decided in order to increase my skill set for MF I had to be very strict with myself and resist the urge to toggle that AF button on. Indeed I believe the experience worked, and to this day I use MF more than AF, like a great deal more!
However I did swap over my Samyang 85/1.4 for the FA 77/1.8 to gain back AF and a lighter more compact lens. I did get caught out on a couple of events where I felt AF would have really helped, just like you say.
But the Facebook post made me think about my future purchases, for example, instead of saving for a FA43/1.9 should I continue saving and just aim for the DFA 50/1.4, not because I am necessarily needing that focal length and aperture (nor would I relish the additional size and weight) but rather the lens perhaps just has a far higher AF success rate in AF.C mode etc.
I would really like to see a
proper Pentax review of AF between more classical lenses (the FA Limited's for example) vs some of the newer glass (DFA's).
Originally posted by automorphism The AF speed is definitely dependent on the AF method of the lens. Newer lenses with a built-in motor will be better at driving the lens elements. That in particular contributes to the speed of locking on to a fixed target. But then there is also the tracking algorithm for AF-C, which is dependent on the algorithms programmed inside the camera. In this regard Pentax lags behind. Basically, overall AF performance is proportional to both the body software and lens AF motor (or with screwdrive, how well screwdrive can drive the lens).
So is there a general consensus that certain lens AF tech is better than other for focusing? I mean I understand some are quieter, some give quick shift etc, but what if all you care about is precision and speed, what lens tech is supposed to deliver best?