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Schiefspiegler kit, anyone tried it?

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#1 plyscope

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Posted 10 April 2013 - 08:45 AM

This is a new telescope in kit form available from Europe. A long focal length unobstructed reflector, 110/3000mm.

Has anyone tried it?

web page

#2 RodgerHouTex

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Posted 10 April 2013 - 09:04 AM

Pretty interesting. I have always wanted to build a Schiefspiegler but never could find the time. Plus I would want something in the 6/8 inch range with the tilted lenses which improve the optical characteristics.

#3 philipdo

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Posted 10 April 2013 - 09:38 AM

Nice initiative. As I understood from a posting by the owner of the company on the Yahoo TCT forum, only the optics and a construction manual are included. So you have to buy materials and make the OTA yourself.

philip

#4 JohnH

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Posted 10 April 2013 - 11:47 AM

There are a NUMBER of TCT designs available in books and on websites where the maker describes all the problems and solutions.

#5 ccaissie

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Posted 11 April 2013 - 07:20 AM

As much as I love the 4.25 Kutter Schief we have in the club made by Norm Meyer, I think 445 euros is steep for a couple of small optical pieces.

Some of the ATM opticians here could do better, I'd think.

The popularity of f/20-24 Schiefs in Europe must be based in the bright sky background from light pollution.

#6 Mark Harry

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Posted 11 April 2013 - 08:00 AM

"Some of the ATM opticians here could do better, I'd think."
**********
And stay in business, pay taxes, and put beans (not steaks) on the table?
Try it, sometime!
M.

#7 StarDusty

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Posted 11 April 2013 - 08:18 AM

I made a Schiefspiegler with the help of Dave and the others at the yahoo group:

http://tech.groups.y...schiefbuilders/

You can read more about this project on my website here:

http://www.clearskyo...le/20-telesc...

#8 plyscope

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Posted 11 April 2013 - 04:52 PM

Thanks for showing your Schiefspiegler Allen, good website!

#9 Pinbout

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Posted 11 April 2013 - 06:56 PM

$583 not including shipping for:

-Optical Elements
-Image quality certificate
-Assembly documentation
-Technical support

for a 4.25in f28

:question:

#10 DAVIDG

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Posted 11 April 2013 - 08:27 PM

It cost me about $75 to build mine and about $40 of that was to have the mirrors coated. All the plans are on Schiefbuilders yahoo group.

- Dave

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#11 RodgerHouTex

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Posted 12 April 2013 - 09:14 AM

Dave,

Very nice looking scope.

#12 ccaissie

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Posted 12 April 2013 - 03:20 PM

If that's the one I looked through at Stellafane back in '05 or so, it's a stupendous scope. However our club member Lennie took the optics award that year. I thought the view of Mars in it was as good as the view in the winning 6" Newt.

#13 DAVIDG

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Posted 12 April 2013 - 04:44 PM

If that's the one I looked through at Stellafane back in '05 or so, it's a stupendous scope. However our club member Lennie took the optics award that year. I thought the view of Mars in it was as good as the view in the winning 6" Newt.

Thank you, the optical performance is excellent in a Delmarva Schiefs. Yes it was displayed at Stellafane in 2005, it also won first that year in the optical judging for "complex optics".

- Dave

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#14 kfrederick

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Posted 12 April 2013 - 04:53 PM

Dave Is there a reason the secondary RC is the same as the primary other than the ease of build . Would a different RC be better . Nice pic ever use the telescope behind you?

#15 DAVIDG

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Posted 12 April 2013 - 05:26 PM

Kevin,
You might be able to tease out a little better optical performance by going with a different radius on the secondary. Then you give up the fact that the tool used to grind the primary becomes the secondary and the primary mirror when figured to the needed sphere becomes the test plate for the secondary. One main reason why this design gives the outstanding performance that it does, is that both surfaces are spheres and have same radii so the primary can be nulled tested with the simplest of equipment, and then used as a test plate to figure the secondary. The result is that the average ATM has a real good chance of making the optics to a level of perfection that the performance of the scope will be what theory shows it can.

- Dave

#16 Mark Harry

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Posted 13 April 2013 - 06:39 AM

I investigated this; and it's possible to "tease" it a bit better. And, change the position of the focus so as to use a lower mount position, etc. Generally a shorter radius on the secondary does the latter, and it would be slightly easier to accomodate a bit more aperture. But as is, the simplicity of Dave's wonderful example, and ease of testing/fabricating has a lot going for it.
M.

#17 Dan McConaughy

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Posted 13 April 2013 - 06:57 AM

I made a number of schiefspieglers a long time ago. The 4.25" is a pain because the mirrors are so small. You can make a 6" f/29 kutter that is easier to make. It's long but works well. The Buchroeder trischiefs work well and you can get some aperture - put one on a dobsonian mount with a drive and you are all set for observing sitting down.

#18 Gary Fuchs

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Posted 13 April 2013 - 11:00 AM

Here's my Delmarva Schief at Stellafane (2nd place tie for optics):

Posted Image

This design is proven, easy to build, and inexpensive. Most of mine was made from scrap yard pieces, but even if you buy everything new it's still not that much.

Posted Image

Posted Image

All the--simple--information you'd need to make one is available here, as well as help from a number of experienced members.

Gary






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