Autofocus - Need answer fast, PLEASE

Jon_Are · Jul 31, 2010

I'm heading out in a couple of hours to take some portrait shots. I'm checking my gear, making sure everything is working OK, and I notice something I haven't noticed before.

(Nikon D80, btw)

When I press the shutter half-way to lock in focus, only the center focus indicator locks in. This is true whether I am in single, continuous, or automatic focus mode.

This happens only when the camera shooting mode is not automatic. In auto, I get the 'moving' focus areas that change as I aim the camera differently.

Isn't this what 'continuous' focus zone mode does? Can I not use continuous in aperture priority, shutter priority, or manual?

I ask because it seems as though I have in the past.

Maybe I'm just crazy.

I appreciate any quick answers.

Robin Usagani · Jul 31, 2010

I am a canon user. But on canon you can pick which focus point you want. Thats what i typically use, 1 focus point at the center so I can really focus on the eye. I am not sure how to turn it all on on your camera.

Jon_Are · Jul 31, 2010

So, do you choose single focus zone, then point this zone at the eye, lock it in, and then re-compose your shot (keeping the shutter button half-pressed) and shoot?

Thanks

Robin Usagani · Jul 31, 2010

Yes.. if you keep doing a similar shot lets say a person with horizontal frame, you can make the top point as your focus so you dont have to move it up and down as much. It is critical to use 1 point focus if you use very shallow DOF. But you should learn how to turn it on and off and how to change the point.

Garbz · Jul 31, 2010

Page 30 of your user manual.

Read up on AF Area Modes. It's a setting in the camera menu.

Jon_Are · Jul 31, 2010

Thanks, guys.

I know about the AF zones / modes.

I just thought you could use the continuous focus mode outside of AUTO (ie manual or aperture priority).

Anyway, I guess it doesn't matter since I'll use the single-point focus as described.

Thanks again.

superhornet59 · Jul 31, 2010

Yeah, the setting's are there in your CSM (custom setting menu) and you can choose. Personally for 'real life' I use the automatically selected focus point setting because I don't have time to switch the points around when there are moving subjects and whatnot. Actually, you know that 'programmable button' you have by the lens? I set it to 'AF Modes' in case it's not selecting the point that I want and I want to change it fast.. but I think Nikon did a good job, it usually focuses exactly on what I need.

By the way you asked of continuous autofocus has something to do with this. Just to let you know, while AF-C will keep readjusting focus constantly, it will NOT continuously change focus points. It will simply keep metering the particular point it initially 'chose' to meter. You need to let go and half-press the shutter button again if you want it to use a different spot which may be the case after re-framing.

EDIT:

Jon_Are said:
I just thought you could use the continuous focus mode outside of AUTO (ie manual or aperture priority).

You can. look at the LCD screen on the top right of your camera. Now a little to the right. see the little button that says AF? Press it and it will switch through 3 modes. AF-S (single - focuses then stops), AF-C (continuous focusing) AF-A (automatic.. I'm not sure what the advantage of this would be, it sounds like AF-C with 'auto shut off' to me.)

Jon_Are · Jul 31, 2010

I think I'm getting confused with exposure zones vs. focus zones.

Let me ask this:

You know the 11 points that are shown in the viewfinder?

How do you know which of these indicate the focus point?

(as opposed to the exposure setting point(s)