Happy Holidays to all!

Shooting some snaps of my son this morning in low light with the Reb 2000 I was having trouble with the AF. Switching to MF I noticed a very large range in lens travel were the indicator said I was in focus. That got me to thinking about an article I read on Robert Monaghan' site about AF focus accuracy. Basically, it said it sucked and you could get better sharpness with manual focus. Of course this is problematic without a focusing aid in an AF camera. My Eos 5 has interchangeable screens but none with a microprism, let alone any choice for the 2000.

So the question is, what do you think? Do aftermarket screens for the 5 make manual focus easier (Maxwell, in particular)? Should I not worry?

Thanks as always, (by the way, my family is now asleep, I didn't ditch them to post this :-))

-- JDR (jrivera@vapop.ucsd.edu), December 25, 2001

Answers

I shot MF SLRs for almost 25 years before buying an Elan II, and unless we are talking Leica M6 or medium format, I would never go back to MF. Microprisms and split image range finders were no thrill for low light, low contrast subjects, especially with slow (f4!) lenses.

AF is very accurate, but not infallible, with operator error providing most of the problems. I almost never trust the auto sensor select features, and prefere to specify the focus sensor and, for people and critters, lock focus on the eye. For situations with limited DOF (close up, long lens, wide apeture, ect) this should provide a high percentage of sharp photos.

-- kenneth katz (socks@bestweb.net), December 25, 2001.

AF accuracy varies from model to model. The EOS 1N, 1V and 3 all have a high precision AF cross sensor. I haven't noticed any difference in accuracy between my EOS 3 and A2 using my EF 50 1.4 USM. However, if you use a 600 mm telephoto wide open the range of acceptable focus is mere millimeters and accuracy will matter.

I read an article in Pop Photo a few years ago where they proved that manual focusing was slightly better than AF. However, they had to use static test targets, a tripod and a magnifying eyepiece to beat AF.

I can say without doubt AF is much better at nailing focus than I ever was with my manual Nikon FM. I remember stopping down to F11-16 and setting the hyperfocal distance on my 28 mm lens to get a simple grab shot. Otherwise, I'd be trying to focus long after the action passed.

-- Puppy Face (doggieface@aol.com), December 25, 2001.

All the Popular Photography piece showed was that the particular camera they used wasn't always as accurate with AF as it was with MF. You could either conclude MF is better than AF, or equally well you could conclude their camera should have been sent in for service!

I've done a LOT (too much!) testing on EOS cameras from the 630 through the 10s, Elan, Elan II and EOS1n to the EOS-3 and my tests all point to the conclusion that a properly set up EOS body focuses as accurately as, or more accurately than, manual focus 99% of the time.

-- Bob Atkins (bobatkins@hotmail.com), December 26, 2001.

Not to mention faster...

Ok, so I've grown up with AF, and never owned (and only once or twice used) an MF SLR. But even so, I don't believe that anyone is telling the truth if they say they could manually focus quicker than an EOS 3 + ring USM can autofocus. I certainly can't.

-- Isaac Sibson (isibson@hotmail.com), December 30, 2001.