OK, so we took some photos this weekend (Kelly to share at some point if you are lucky) and I realized that I haven't a clue how to do something that B. Peterson describes in his book Understanding Exposure.
When discussing how to focus the lens when taking large depth of field photos, he recommends presetting the focus via the distance settings. How the heck do you do that? From the text, "first set your aperture to f/22 and then align the distance above your distance-setting mark on the lens. Your focal length will determine which distance you use."
OK, so looking at our lenses, nothing is jumping out at me. What should we be looking for?
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It sounds like Peterson is talking about the hyperfocal distance. I have yet to experiment with this myself. But basically, focusing to the hyperfocal distance will give you the maximum DOF given a aperture setting. A simple hyperfocal/DOF calculator is found here: http://www.outsight.com/hyperfocal.html#hyper
There are better calculators, I'm sure. There are event ones for Palm OS which I plan on downloading to my Treo.
Anyways, as an example, let's say your parameters are: 35mm at f/22. The calculator says you need focus at ~6. What does this do? 1) The in-focus near field is half the focus distance (~3 ft). 2) The in-focus far field is infinity. So everything from 3ft - inf. will be in focus. With me so far?
So, assuming you're using your kit lense, then the focusing ring is located furthest from the camera body. Put your camera into manual focus mode, and turn that dial so that 6ft is near the center white dot. So now, assuming you're zoomed to 35mm at f/22, everything in your picture will be in-focus from 3 ft to inf. Got it? Wikipedia has some good info on hyperfocal distance that I've been trying to understand. But it gets into the circle of confusion explainations and, frankly, I just don't care to understand that much about it.
So hyperfocual distance is a function of your aperture and focal length. It will give you the greatest DOF for landscape pictures.
BTW, if you are taking landscape pictures and need the ultimate sharpness, I suggest using mirror-lock up and the two second timer.
Can't wait to get out and start using my camera this spring. Still a little too cold for me...
Yea, too complicated for me. Auto focusing I use.
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