I played with it some last night. My reaction to it just gets worse. I
tried it on my *ist D.
In indoor light, it does not autofocus correctly. Going from distance to
macro, or vice versa, often it simply could not find focus. Other times
it would, but would take a very long time. Sometimes it would autofocus
incorrectly, but report that it was in focus. For example, trying to get
macro autofocus on some text a few cm. away, it would sometimes focus at
about 3 m, then the focus confirmation signal would light up.
(Yes, I know about using manual focus for macro. That is not my point.
My point is that the lens does not perform correctly.)
Herb Chong (I believe it was him) has commented on the use of friction
tape in some of the FA* lenses. This is part of the manual focus
mechanism, but allows the focus ring to turn past the points where it
should end. I am not familiar with friction tape, but it seems that the
D FA 50 may have it in abundance. The focusing ring turns easily past
its end points, but the drag increases so much that it feels like the
lens is being damaged.
Manual focus gives good resistance, but the resistance is -- well --
strange. It is unlike any manual focus I have previously experienced. It
is so strange that I don't know how to describe it. Perhaps I might say
that it feels like worn out sandpaper.
Friction tape sounds to me like something that would need to be replaced
if the lens is used heavily. Is anyone familiar with it? I can foresee
in a few years needing to send the lens to Pentax, then Pentax saying
"Sorry, we have no parts to repair it."
In macro mode, the barrel extends out to the edge of the hood. No doubt
the hood is meant primarily to shade the front element from the sun. But
it has the secondary function of protecting the lens when the flimsy
barrel is extended.
I have four DA lenses, and in comparison they all feel very sturdy. The
DA 16-45 has an extending barrel design, which initially made be
sceptical about it. But it's optical quality is so high that I accepted
the physical design. I just always zoom the lens back to its shortest
length after each shot. I learned that one must do this from an FA 24-90
that was damaged when I left the barrel extended.
I have the FA 100 F2.8 macro and the Sigma 180 f3.5 macro. They are too
big and heavy to travel with. I wanted a small, light 50 macro for
travel. I bought the D FA, rather than a used FA, because of its light
weight, because of the rebate, and to support Pentax. I am still
undecided whether to keep it.
I hope that this is not indicative of the build quality we can expect in
future D FA lenses. If so, my interest in the forthcoming D FA "high
performance telezoom," and in a future full-frame Pentax DSLR that would
use D FA lenses, just took a big nosedive.
Joe
- D FA 50 F2.8 Macro Update (a bit long) Joseph Tainter
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