With the 4T bodies I have to occasionally recalibrate the focus via the
adjustment knob on the left side of the prism (my wife uses my gear now and
then and her eyes see differently), and last time I did this I noticed one
of my adjustments was off by three clicks from the other two bodies. I went
back and did it again, and I'll be damned if I could tell, for sure and for
certain, if it's right now or not. My exposed film usually does come back
to me properly focused, though, so I suppose any errors in focus are on the
user--namely, me.
Check and double check to see you've adjusted your 4T correctly for your
eyes. With the all-matte 2-4 it isn't so easy to tell. (Somewhat easier, I
believe, with John Hermanson's lines scribed in, which happens to be my setup.)
I don't bother for street work (as often as not there simply isn't time),
but Moose has a good point re the use of a wide-open aperture for hedging
your bet with focus, then closing down for the actual shot. Try that as well.
Re fast lenses and "inherent" problems: as a matter of fact there are none
to speak of, and when it gets down to it your work ought to come out better
still. All of the Zuiko fast glass is superior to the slower counterparts
as far as I know--by reputation, surely--I don't own the 24/2 or 50mm macro
f/2. It's true the 50mm f/1.2 wide-open leaves you with a razor-thin DOF,
but I wouldn't suppose you'd use this lens opened up unless you had an
extreme low-light condition and your camera properly supported with the
time to fiddle with its focus until right. I have used it wide open in the
street at night, but my subject's were always some distance off and so I
was shooting at close to (or beyond) infinity.
Finally, as most lenses have (on balance) a sweet spot just about in the
middle of the f-stop range, and assuming you know this and endeavor to
shoot at these preferred apertures, critical focus should not often be an
issue--the afforded DOF at these apertures tends to ensure acceptable
quality in most work--though I've somehow managed to defeat that "wisdom"
over the years more times than I care to admit in mixed company, even when
the work had been intended for half-tone presentation. <g>
Tris
At 11:54 AM 2/20/2003 -0800, you wrote:
Is the screen properly seated in the holder and the holder frame fully
snapped into place? I have replaced 1-13 screens in OM-4(T) bodies with
2-4 and 2-13 screens without any focus problems. Is it possible the pin on
which the mirror rests got bent while you were in there? That will throw
the focus off - infinity or scale focus will still be correct on the film,
but the viewfinder focus will be off.
Ralf Loi wrote:
Some time ago I bought a 2-13 screen for my OM-4T. For some reasons (too
long to explain here), I didn't notice this strange
behaviour: with the new screen the focus seems off.
Is it possible focus was not off at first, so you didn't notice it because
it wasn't there, and something else has occurred since then?
This problem is evident when pointing at some very distant subject (at
infinity), where every lens
seems to focus correctly at the (say) 10m mark instead at the infinity
mark. Moreover, the problem is more noticeable with some lenses (28/2 and
50/1.8) and less with others (21/3.5, 135/2.8).
Yes, any such problem will be more obvious with faster lenses. Remember
focusing is always done at full aperture, where depth of field is least,
thus assuring most accurate focusing and enough light to see to focus.
Moose
< This message was delivered via the Olympus Mailing List >
< For questions, mailto:owner-olympus@xxxxxxxxxxxxxxx >
< Web Page: http://Zuiko.sls.bc.ca/swright/olympuslist.html >
|