Hi Don -
I just tried out my FA50 f1.7 and *ist-D, and they worked fine together - I ran a series of shots up along a 1 hour lab envelope (a nice hi-res target with the grid for reprints on it) and the lens/camera snapped into focus each shot, differentiating a matter of inches each time. They all looked sharp in the finder - but that finder is pretty small.
If the camera focuses correctly with some lenses and not others, I'd suspect a problem with the lens. In my experience, the *ist-D autofocus with slow lenses (like f5.6) is not so good, but it is very good with faster lenses. Your experience seems to be different - though, what is the aperture of the DA 16-45? Maybe you are just seeing the results of more DOF than you get at f 1.7 and f 4 with the FA 1.7 ???
- MCC
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Mark Cassino Photography
Kalamazoo, MI
www.markcassino.com
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----- Original Message ----- From: "Don Sanderson" <[EMAIL PROTECTED]>
To: "PDML" <[email protected]>
Sent: Saturday, April 16, 2005 4:16 PM
Subject: ist-D Focus Woes, More Info.
I'm not sure if I need a camera repairman or a psychologist but here goes. I tried A50/1.4, the FA50/1.7 and the DA 16-45 on a yardstick from about 3 feet away. Manual or autofocus were all spot on in 24 shots.
I took the 2 AF lenses outside and took shots of the flowers, weeds, leaves etc. I found in the grass. The reason I chose these is that the grass shows clearly whether focus was right on, long, or short. It's a bright but overcast day so light is very even, speeds were between 1/125th and 1/500th. Shots at maximum aperture, AND the FA50/1.7 at 4.0. I kept the intended subject centered in the viewfinder to make it obvious what I was aiming at.
Here's the score: FA50/1.7 at 1.7, 20 misses out of 24, almost all were focused long. (Past the intended point)
FA50/1.7 at 4.0, 14 misses out of 24, again almost all were long.
DA16-45/4.0 at 45/4.0, *2* misses out of 24, one was long, one was short.
Again, all looked sharp in the viewfinder, if it was an obvious 'miss' I let the lens re-focus. OK, so the DA is my hero. ;-/ Any theories as to the extreme inconsistency in the FA50 (And A50) ???????
And the main question:......................... HOW can a viewfinder lie, but only SOMETIMES??
Don (The Thoroughly Frustrated)
PS: I have straight from the camera samples to prove I'm not just on "Happy Weed". ;-)
