What on earth.....?

[gsjag]

Hay! Anyone know what on earth you'd use one of these for (a real star party gathering perhaps)?

"Zeiss Giant astronomical eyepiece H-160mm with 80° FOV, 180mm fieldstop, 3900 gr., M200 thread". See picture at:

http://www.apm-telescopes.de/secondhand.php?action=showpic&id=14&picnr=1

Gary

[Greg]

:shock:

Sorry,

I'm normally pretty good at this sort of stuff but......

[lunator]

M200 Thread?

Would it screw into the body of a 1980's Practika camera?

[GazOC]

I'm pretty sure its for ariel surveilance. You can cover a big stretch of ground from the air with a lens like that.

[John]

It'a an eyepiece (okular in German) - they are specially made for professional telescopes - I believe that Zeiss make a small range of them. I saw them priced somewhere - about 3,000 euros !.

John

[Astroman]

It'a an eyepiece (okular in German) - they are specially made for professional telescopes - I believe that Zeiss make a small range of them. I saw them priced somewhere - about 3,000 euros !.

John

That's interesting, since professional telescopes haven't used eyepieces since the 1920's or so. Although it would help a lot in certain cases. Like, take a 61" scope like the one on Mt. Bigelow in AZ. With a 55mm EP, you START with 480X. My lowest power EP-a 32mm-gives about 780X. FOV is ~15 arcminutes.

[FLO]

M200 Thread?

Would it screw into the body of a 1980's Practika camera?

The original screw-thread Prakticas used M42; they later switched to bayonet.

[GazOC]

I'm stuckin' with my first guess!! I've seen lenses with these specs on EBAY USA and they've always been for widefield surveilance, either air to ground or (now and again) on older missile guidance/ tracking systems.

[FLO]

It is the right size for an aerial surveillance lens.

After saying that, they are normally designed to fit plate cameras or medium format cameras.

[Ant]

That's interesting, since professional telescopes haven't used eyepieces since the 1920's or so.

You sure? I used a brand new Parks Gold EP that I had just purchased in one of the scopes at the mcdonald Observatory in Texas! (that was 1989).

An

[Astroman]

That's interesting, since professional telescopes haven't used eyepieces since the 1920's or so.

You sure? I used a brand new Parks Gold EP that I had just purchased in one of the scopes at the mcdonald Observatory in Texas! (that was 1989).

An

Yup. Once film made the scene, most observations were put on film or actually, glass plates. Large-format plates were used extensively. There was a huge project at the US Naval Observatory in Flagstaff that scanned thousands of Palomar plates to digital form in the 80's. Then, when CCD's came in, every major observatory converted to them and increased their scope's efficiencies by a couple orders of magnitude instantly. And while most science is done with a spectroscope, not a visual imager, (unless it's UBVRI photometry), the results were still put on plates and now on CCD image files.

Some observatories do public outreach observing and still have EP's around. That's one of the reasons I mentioned Mt. Bigelow, since one of my cohorts recently observed through the 61" with an actual EP. Most of the time, it's a CCD setup, but they got a break from one of the main observers there. Professional observatories that have been overrun by cities and their light pollution still do visual observing, mostly for the public not for science. I know McDonald has a great outreach program, as does Lowell here in AZ, but their science is done from a different, darker site. Lick, Lowell and even Palomar are being overrun and have satellite observing sites, while they still do public outreach onsite.

Kitt Peak has a wonderful public program that uses a 20" R-C and an EP-the only telescope on the mountain with an EP. In the advanced program, you can observe visually or they'll attach a CCD and image for you. The point is, Kitt Peak, the largest collection of optical telescopes on Earth has but one telescope with an EP, and it's stricktly for the public. Mauna Kea hasn't a single telescope at the summit that is even capable of having an EP. To do that, you have to go to the Onizuki (sp?) Visitor Center, down at 9,000 ft.

Anyway, that's my view. I'm pretty sure the others have pegged it accurately as a wide-field reconnaissance scope hooked up to a wide medium to large format camera.

[gsjag]

Thanks for all the thoughts and suggestions guys. With regard it being a wide-field reconnaissance scope , I would add that it's being sold as Giant astronomical eyepiece H-160mm with 80° FOV. Of course, that doesn't mean its the right description!

Gary