A short lesson in depth of field
This was shot at an aperture of f3.5. It was shot on a kit lens, the Pentax-DA 18-55mm F3.5-5.6 AL II to be exact. It’s what comes with a Pentax K200D, and the lens that I bought for my K20D. This lens is a good lens for the money (about $100), but the lowest aperture is not particularly low. I have a Pentax A 50mm lens that has it’s biggest aperture at f1.7. That’s a low aperture.
But Marc, that’s a lower number but you wrote that the aperture was bigger. What gives? Well, the lower the number, the larger the aperture (opening). So what? The photo’s background, above, is somewhat out of focus, leaving the viewer with the sense of depth that would not occur had the entire photo been in focus. The lower the aperture, the less of the photo that is in focus, the more a sense of depth is felt by the viewer. Make sense?
If you want to have a little fun, mess with your aperture on your camera. Your photos will turn out differently than if you leave all of the work to your camera, and you might end up with a result that you like better than the automatic settings.