I have recently moved to rear button focusing (i.e. I use the back AE-L/AF-L to engage the auto-focus instead of pressing the shutter halfway). I also have my auto-focus set to AF-C to track the focus at the selected focus point. Here's my question:
Is the auto-focus going to continue to track in continuous high speed shooting (CH) mode as long as I keep the shutter depressed or does depressed the shutter disengage the autofocus even though I may keep the AE-L/AF-L button depressed? The autofocus appears to disengage but it's a little hard to tell because generally things don't move too much between exposures in that mode.
I can't find any explicit explanations in the manual. Does anyone have any insight into how these settings may interact?
>Is the auto-focus going to continue to track in continuous >high speed shooting (CH) mode as long as I keep the shutter >depressed or does depressed the shutter disengage the >autofocus even though I may keep the AE-L/AF-L button >depressed?
Yes, AF will do its magic as long as you keep AE-L/AF-L button pressed.
As Vlad says, the camera will do its best to track the subject as long as you keep your thumb on the AE-L/AF-L button.
It's not guaranteed, of course - if the subject moves too fast or in an unexpected direction, the AF system may lose it for a short time. It should pick up again, but sometimes it can be necessary to take your thumb off the button and re-press it to start over.
Does it matter which AF-Area mode I'm using (single point, dynamic, 3D, etc). I tend to use AF-C, single point and then position the active focus point at the element I'm focusing on. Do I need to be in a dynamic mode?
>Dumb, newbie question... > >Why? What is the advantage of using the AE button versus >half-depressed shutter? > >
Same dumb question I had initially... I find it gives me far more control over when the AF engine will engage. I've had some frustrating situations in the past when I'm shooting single images (non-continuous) and the AF focus engages when I don't want it to and screws up the shot. A couple of examples:
1. Very often if I'm shooting macro I'll use AF to get close and then shift to manual focus. When the shutter controls the AF it'll try to refocus between shots (unless I switch the lens or body to MF which usually requires me to move the camera and mess up my distance).
2. If I'm shooting in low light the camera may start to hunt in between shots. So it's nice to be able to get the camera to stop trying to re-focus in low light if I know the focus point hasn't really moved.
So I find that back button gives me far more control over focus. It allows me to switch between AF and MF quickly and easily. It also allows to to ensure the camera won't start hunting in cases where it may try to refocus.
I'd try it for a week or so and see what you think. Once I'd used it for a few days I'm never going back. You do end up with some completely out of focus shots initially because you forget to focus...
Thank you so much for your complete answer. So you press your shutter half way, and once you have your objective in focus, press the AE/AF focus. Right? Just pressing the button will NOT initiate the focusing process. Since I do 85% macro photography (for dental surgery), I find your idea FANTASTIC.
I don't think that's what Stuart (myverse) meant, but I guess he'll confirm himself
The suggestion above was to use the AE-L/AF-L button to initiate autofocus, and NOT the shutter release button. This is a different option from using a half-press on the shutter release button to initiate autofocus, and then a press of the AE-L/AF-L button to lock focus. This selection is made using Custom Setting f5, and is explained in detail on page 232 of the D7000 manual.
> So you press your shutter half way, and once you have your objective in focus, press the AE/AF focus. Right?
That's not what I meant - although I suppose you could achieve the same control that way. I personally find it more natural to control when I want the auto focus to engage rather than controlling when I do not want it to engage. Most of the time I find I spend most of my time with auto-focus disengaged (once I've gotten the initial focus) so I only have to repress when I want to recapture focus.
But I can see how you could do exactly what I've described before using the AE/AF button to disengage the auto-focus instead of engaging it.