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
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