After doing some research over the past couple of days about
astrophotography and telescopes suitable for the task, I was wondering
about the Zuiko 1000/11, Gary Reese's tests and how it might perform if it
(the lens) were mounted and used as one would a refractor with camera on
the back.
Telescope mounts and the tripods for anything 1000mm and up class are
pretty healthy devices. Of course, they're *not* the type of thing one
would normally haul around for a wilderness trek, but then I doubt very
many backpackers would take a 1000/11 with them for a trek of any distance
(or climbing difficulty).
-- John
At 06:58 PM 8/24/03, Moose wrote:
Lama-Jim L'Hommedieu wrote:
Right. If Gary Reese can't solve it, with all of the precautions and
experience he brings to the table, what chance do I have?
But how experience much did he have with such lenses when he did the
tests? The tests were an evolutionary process, where he learned as he
tested and tried new things. I have no direct knowledge where in that
process the 600 and 1000mm lenses were tested. The cameras used suggest
that the 600mm was done early and the 1000 later. And look at that, the
600 with only mirror lock-up does less well than the 1000mm with aperture
and mirror pre-fire. Perhaps 2 tripods or a lens support isn't the
solution. Was the camera held as Oly suggests or was a cable release used?
What would a nice bean/sand/whatever bag resting on something big and
solid under the lens do to reduce vibration through absorption? I've found
that resting 300mm on a car window with the engine off and without any
mirror/diaphram control to work well on at least a couple of occasions.
PPSS. On a poured-concrete pillar, bolted to bedrock. Or maybe just get
a compact telescope and a T-mount because many of these
things have already been adressesed.
I have a compact telescope on a T-mount, 1000/11 in fact, and have had
some decent results with it on a heavy tripod, but controling vibration is
still an issue. One has the usual problems of mirror lenses with halo-like
out of focus images and the inability to stop down to incease DOF. Also,
the tree some hawks were nesting in insisted on waving in the breeze,
limiting the length of shutter speed. I don't think any really long lens
is easy.
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 >
|