focusing using a tripod

[TheWengler]

Originally Posted by westy79

thanks Lukas, so in this shot f10/11 is fine and the focus point of beyond the pond is ok. But if there was something of interest close to me, maybe jump to f.16(but still focus far away or on the close object) I know digital is great for experimenting and i should keep shooting, but if i can eliminate the basic errors it will save the guesswork.

Without a focus distance scale it's going to be hard to tell what your camera is doing. I've heard people say focus 1/3 of the way into the shot. I don't really practice that, but it seems like it might work.

Originally Posted by westy79

Excuse my schoolboy knowledge once more, but how do you set the lens to infinity focus. Heard lots talked about infinity but my lens has no markings on.

Just AF on something far away. On this shot it was too dark for me to AF on my main subject (the boat), so I zoomed in on some of the lights and used AF. The lights and the boat aren't the same distance away, but they're both far enough away that it doesn't matter which I focus on.

[toriaj]

Originally Posted by TheWengler

Just AF on something far away. On this shot it was too dark for me to AF on my main subject (the boat), so I zoomed in on some of the lights and used AF. The lights and the boat aren't the same distance away, but they're both far enough away that it doesn't matter which I focus on.

I've never heard of zooming in to get focus, then zooming back out! Would it work on a portrait at wide aperture, say you zoom in on the eye, focus, then zoom back out? If so, I guess composition would be the biggest issue, because the focus area (eye) would have to be in the middle of the frame.

[Dread Pirate Roberts]

Originally Posted by TheWengler

I may have a vision problem,

Yep any time you look at water Lukas it's all misty and artfull

[erichlund]

Originally Posted by toriaj

I've never heard of zooming in to get focus, then zooming back out! Would it work on a portrait at wide aperture, say you zoom in on the eye, focus, then zoom back out? If so, I guess composition would be the biggest issue, because the focus area (eye) would have to be in the middle of the frame.

You haven't heard of it because the distance marks on the scale are more guidelines than actual distances. As the lens is zoomed, the actual focus for a given distance changes slightly. Of course, if you are relying on a small aperture to give you a high depth of field, and you're not in the habit of achieving critical focus on something specific, then you will not really notice that you're simply within the depth of field and approximately focused on your subject.

[TheWengler]

Originally Posted by toriaj

I've never heard of zooming in to get focus, then zooming back out! Would it work on a portrait at wide aperture, say you zoom in on the eye, focus, then zoom back out? If so, I guess composition would be the biggest issue, because the focus area (eye) would have to be in the middle of the frame.

I've never done it for anything like that. I only do it when it's too dark for AF to focus on my subject. Works well for landscapes because I don't have to worry about my exact focus point.

Originally Posted by Dread Pirate Roberts

Yep any time you look at water Lukas it's all misty and artfull

Only when I'm not wearing my glasses

Originally Posted by erichlund

You haven't heard of it because the distance marks on the scale are more guidelines than actual distances. As the lens is zoomed, the actual focus for a given distance changes slightly. Of course, if you are relying on a small aperture to give you a high depth of field, and you're not in the habit of achieving critical focus on something specific, then you will not really notice that you're simply within the depth of field and approximately focused on your subject.

Sometimes at night I can't stop down as much as I'd like, so maybe I'll run into a problem at some point. I haven't had any issues with sharpness yet though. MF would have been nothing more than a guess. I was having trouble even seeing my subject in the frame to set up the composition.

[achuang]

Lukas, do you ever use a torch to help you see, or illuminate the subject just for focusing purposes? I suppose it's one more thing to carry but I'm sure it'd be useful.

[TheWengler]

Originally Posted by achuang

Lukas, do you ever use a torch to help you see, or illuminate the subject just for focusing purposes? I suppose it's one more thing to carry but I'm sure it'd be useful.

I have before, but it can be a pain. I carry a small one, mostly for finding my way back in the dark after those late sunset shoots. It's not super bright.

[marcelobf]

You can use the tables below to try to understand better how DOF works:

http://www.dofmaster.com/doftable.html
http://www.dofmaster.com/dofjs.html (with images)

[BikerJohn]

Excellent site on the depth of field information. Really helped me understand hyperfocal distance. That's very important... As far as I can tell that is the minimum distance the lens needs to be focused in order to get the Far limit to equal infinity, for a given aperature and lens focal length.

[Dread Pirate Roberts]

Got it in one BJ