Good focus with digital AF SLRs depends on choosing the focus point andplacing it on the right spot on your subject. Perfect focus with fast-moving subjects is challenging with either manual or AF.
I prefer my Canon EOS 1D mk II's 45 AF sensor locations to the EOS 20D's 9 locations, but I use the same procedure with either camera. I see a shot I want, choose the point of focus for the composition, then track moving subjects and shoot when I like what I see. I used that procedure in both of these wildlife images. The originals are very sharp at the eyes and the feathers. Images were made with EF 500mm f/4L IS (robin snarfing berries) and EF 400mm f/4 DO IS (snowy egret in the pink): http://tinyurl.com/3zoq6 http://tinyurl.com/4fner It works for sports too, like in these shots of pro mountain bike racers: http://tinyurl.com/4o2j2 http://tinyurl.com/yc6x2f While the 400mm DO IS was in the shop awhile back, I used my backup 400mm f/6.8 Telyt. Here's a manual-focus shot made with the 20D and 400mm Telyt: http://tinyurl.com/y2ub5j(I use a Katz Eye focusing screen with split-image focusing aid in the 20D. The split stays bright at f/6.8.)
In the original image, this young Cooper's hawk's feathers are sharp. The eye is very slightly soft, from my (mis)focusing. It may also be the limitations in a two-element achromat showing up in a digital image. The sharpest feathers in this Telyt image don't look as individual-feather sharp as those in the robin image from the 500mm f/4L IS. With manual or auto focus, you can anticipate subject placement andchoose photo situations to give the composition you're after. Sometimes anticipation isn't possible, like in David Young's rodeo shot. It's still a great shot.
Will you lose a few shots due to not getting the sensor on your subject where you want it? Probably. With a manual focus lens like the 400mm f/6.8 Telyt, will you lose a few shots due to not focusing fast enough on the part of the subject you want to be sharp? Maybe due also to vision problems? Again, probably. But perfect sharpness isn't necessary when the image tells the story well. Mark Bohrer Mountain and Desert Photography www.mountain-and-desert.com Wildlife on the urban edge ========================================================= To Unsubscribe: Send email to leica-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field. The acknowledgment that you then receive MUST be replied to per instructions. You may also log in to the Web interface to unsubscribe.