On 6 June 2011 13:40, Eric Weir <[email protected]> wrote: > It was sunny mid-morning. The camera's a *ist DS. The lens was an M 135/3.5. > ISO was 200. Aperture was mostly around f11. About half the images were shot > at 1/250, half at 1/180. I kept focus set at infinity. > > I thought surely, at that speed, with that focus, at the distance at which I > was shooting I'd get a few sharp well-composed images. A handful -- less than > five -- are so-so, but not really sharp. The rest are all fuzzy. > > Why can't I get a sharp image?
Depth of Field? A football pitch is typically 360' by 160' (pinched from wikipedia ;-) I'm assuming you're standing on the closest sideline to the action? So the players are less than 80' away, yet with a 135mm lens @ f/11 & focused to infinity nothing's sharp until you get out to 265'! ( http://www.dofmaster.com/doftable.html ) ...and then as Doug says, motion blur. I'd probably try ISO 400 @ 1/400s (to help with motion blur) & f/16 and focused closer, say 40' or 50' (both to help with DoF). That gets you everything from 30' to 50' (or 40' to 70') in focus. I'd say that focusing at the hyperfocal distance even at f/16 still doesn't get you close enough. -- Eric -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
