Re: Auto-focus on digital SLRs.

Manual focus is a wonderful tool.
Unfortunately the viewing systems in most autofocus SLRs, film and camera,

are not made for critical manual focusing. Most have at best a ground
glass 
surface that tends to make thinks look focused that may not be. Also
because 
many autofocus zooms have a maximum aperture of f4 and go down to f5.6 at 
the long end the viewing image may be a bit dim. The manual focusing cams
on 
many autofocus lenses do not have the firmness of manual focus lenses
either 
but there are not many complaints about slipping out of a manually
adjusted 
position.
Some   dSLRs, like the otherwise great D70, are severely hampered by the
dim 
small view they give the user.
Modern SLR autofocus under most cir***stances however is probably more 
accurate than manual focus overall under most conditions. Adding facial 
recognition algorithms may also be an advance, although I have not 
experimented much yet with my camera that has this feature.