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Re: [OM] Oly 1000mm f-11 Lens Experience

Subject: Re: [OM] Oly 1000mm f-11 Lens Experience
From: "John A. Lind" <jlind@xxxxxxxxxxxx>
Date: Mon, 25 Aug 2003 00:29:29 -0500
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


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