#59. "RE: How do I get sharper, in-focus pictures? Want to learn!" In response to In response to 57
Focus tracking lock-on was really designed for a very specific situation, such as this:
You are tracking the quarterback as he fades back to make a pass. A ref or other player runs very quickly through the scene. In that case you do not want the camera to try to focus on that person running across the viewfinder or running across your active selected focus sensor.
Lock on is supposed to delay the refocus, and supposedly only when something closer than the current focus point "hits" the focus sensor position.
The one time I seriously had a problem to solve, I am focusing on a horse running down a track, almost directly toward me. Because of my angle and other issues, on occasion I will focus on the background, which is a stand full of spectators.
The camera just LOVES to focus on faces, where it has problems focusing on a solid white or black horse, for example. Or a knight in shining armor (which is actually the case here ). Given a choice (focus sensor half on the subject) it chooses the faces every time.
Never once did I get lock on to work there, even with Lock on fully enabled (slowest). And I came to the conclusion that it was designed to ignore only things in front of the active focus distance, not "things behind", such as my focus tracking errors. And that is the most common of all focus errors- switching to the background.
I've shot 4 different cameras with focus lock on for over 8 years now, and I have never been convinced it really did anything useful or it even works in the real world. (Might work in a lab test or on a football field). But regardless of my own impression, which could be debated...
If your whale breaches, then you need to follow the whale or use some sort of dynamic sensor mode that is supposed to track the whale. There is (presumably) nothing that will briefly come between you and the whale. There is no purpose for lock-on here.
I have always had a concern that when using lock-on, especially the "slow" modes, that the camera can not possibly differentiate between something coming between me and the currently focused subject, and me switching quickly to a closer subject. The camera cannot read my mind.
I suspect that lock-on effectively slows down the responsiveness of AF, which could be a cure worse than the disease. And except in rare cases, if at all, I am not convinced the disease is even curable.
Because of those concerns, and because I do not shoot football, or rarely anything that lock on might help, I often turn it off, and more importantly, I do not expect it to bail me out of any poor focus tracking on my part.
Just to say I think you should look elsewhere to solve any focusing issues. If you have lock on enabled and you find the camera sluggish to refocus when switching targets, then turn it off.
Back to your whale... on occasion I have a problem where I need to shoot something that may unpredictably and quickly move within the viewfinder. It is often a bird, on a perch, that I expect to launch off the perch. But I have various reasons to believe I cannot actually track the bird using continuous AF.
In that case I will lock focus as long as my distance stays within what I hope to be the DOF and fire away without activating focus - using AF-On and turning off shutter button focus activation. Alternately it can be done with the focus lock thumb button.
Obviously that is fraught with peril, mainly that the subject somehow drifts out of focus, or when it finally moves it moves out of the plane of focus. But it is a potential solution to some problems.
I've never shot whales breaching but I understand the idea. As I understand it, whales move fairly slowly and so do most whale watching boats. At the distances I suspect are involved there is some DOF there, and you can touch up focus as things tend to drift about.
I am generally suggesting that there are cases where focus should not be constantly engaged, and that may be one of them. But it is a tricky business.
_________________________________ Neil Nikonians Team My Gallery