AF/AE lock

[slayer7124]

Can someone please explain to me the purposes and advantages to using AF/AE lock. I have the D80 and in one of the menus it lists AE lock, AF lock. AE only, etc. etc. I kind of understand the meanings from reading the manual, but when it comes to shooting I never know if or when I should be using it. Any help would be great, thanks!

[Frog]

I've been meaning to ask that same question? Thanks for beating me to it.

[Dylan8i]

the way i understand it ae = auto exposure, af = auto focus. so depending how you set the ae/af button when you press it it locks which ever you have it set ( one or the other or both) and then while holding the button down you can recompose a shot and keep the focus and exposure the same.


not supre useful if your using single servo focus or manual exposure... but can still be very usefor for getting quick pics while in auto modes.

[slayer7124]

Yea, thats what I got from the manual and whatnot. They said, for example, if you had a bright background and were taking a picture of a person, use AE on the person, then hold the button and pan out to get the background, that way the person would be properly exposed, but couldn't you just do that right from the start without using the AE button? That's were I get confused, unless, like you said Dylan, its more useful for auto modes.

[fx101]

The AE/AF lock is actually meant to be used in continuous servo mode, when you know a subject is going to come into a frame at a certain distance (i.e. will be in focus) and exposure. Also, if you have a very dull (low contrast=hard to focus) subject, you can meter and focus somewhere nearby and hold the focus and exposure, shoot, and then quickly engage the servo to focus on your next subject. In tennis for example, while using a telephoto the camera sometimes wants to focus on the player's arm and not body, leading the camera to wildly focus and sometimes expose wrong. If you manage to meter the body at the baseline, when the player comes to the baseline you can shoot away without worrying about the camera doing anything weird. When the player moves away then you're forced to let continuous AF and the meter do its thing.

[another view]

The AE/AF lock is actually meant to be used in continuous servo mode, when you know a subject is going to come into a frame at a certain distance (i.e. will be in focus) and exposure.

In this case, it wouldn't shoot until it saw something in focus. I remember at Nikon School one of the teachers used a setting like this on the multi-control back (remember those!?) to "catch" who was stealing all the seed from his bird feeder. He got a nice shot of a squirrel.

Honestly, I've never used that button on any of the Nikons I've had. It's really more of a sports thing, which I don't do. With custom settings you can have (for example) the spot meter follow the AF sensor (or not), and I always have the camera set up that way. If I need to lock down the focus, I usually just put it in Manual focus mode if "S" and holding the shutter half way down isn't going to work.