Thanks for the more technical thoughts. Ideas I’ll try next time I’m out there shooting pics: Locked aperture. I’ll try to lock my camera to f/8. On my Pentax these modes are called P, Tv, Av, and M. So I’ll use Av and lock it at 8. I’ll also have to look at DoF? some more. In the kind of compositions I like, it rarely comes up, however. So that will be a low priority thing for me. Another thing I’ll have to remember is to switch my camera out of ISO auto mode where it will pick 200, 400, or 800, but never 1600 or 3200. And I keep forgetting about it. Maybe it would have helped when I was trying to take pictures in Kyoto at night.
Something I noticed while in Japan: For some pictures there seems to be a slight shadow in the corners. As if I were taking the picture through a tunnel. Is my lens somehow eating up too much light? When will this happen and how can I avoid it?
– AlexSchroeder 2007-10-07 20:58 UTC
Hey, that shot looks great to me! It would have been cool to see how it turned out at high ISO in monochrome though. Maybe next time, eh?
The darkening in the corners is most probably Vignetting (link to Wikipedia), and it’s common if you’re shooting at a wide-angle with a narrow aperture. Personally, I quite like it in photos as it helps frame the shot, but it doesn’t work for all images.
If you want to avoid it, use a higher ISO or slower shutter speed so you can use a larger aperture. Alternatively, it’s easy to fix on the computer – Photoshop CS2, for example, has a Lens Correction filter which does just that, and Image Magick does a great job of Vignette Removal.
– GreyWulf 2007-10-08 16:27 UTC
Ah, that would explain where I got the effect from. What happened was this: The light in Japan was very strong, so that any shot with a lot of sky in it would have a blue sky and everything else would be way too dark. I’m sure there’s a technical term for it: Low dynamic range of the sensor? So what I’d do is take a picture on auto setting, look at it on my little monitor and decide it was too dark, examine the aperture and shutter speed the camera had picked, switch to manual mode, and either fiddle with aperture or shutter speed. Since the two seemed pretty much equivalent, I might have fiddled with the aperture instead of picking faster shutter speeds. Thanks for the info.
And I need to find the setting that over- oder underexposes so that I can stick to automatic. And I need to figure out whether using the “Snow” scenery would have helped in Japan…
– AlexSchroeder 2007-10-08 23:15 UTC