Schiefspielger telescopes

[MattT]

Does anyone have or made a Schiefspiegler Telescope?

Now my massive mount is just about done I'm thinking a Schief might just be the best scope to use...or an 8" Istar frac should I be so lucky....but a 10-12" Schief is a real possibility.

Any reason why not to do an ATM Schief????

Yes I know they are long fl scopes so a narrow TFOV.

Matt

[Wavytone]

The big question for you is what's the seeing like at your site. There's little point in a scope that only has high magnification if the seeing isn't frequently a match for it - I've known one who bought a superb 12" mak and sold it later for this reason.

Otherwise stick to a scope around f/7...

[Merlin66]

Barry Alcock built and used a Shiefsiegler for many years, it was f22 If I remember correctly.

[Rod]

Hi Matt

I would definitely talk to Barry. He has switched from a large schefspiegler to a large refractor. I remember him saying he believed the long distance between mirrors had an adverse effect on the schiefspiegler. He felt the schief was a design better suited to smaller instruments.

The yolo design might be worth a look. It allows a faster focal ratio - F12 to F15. The secondary mirror is a bit more complex though.

Rod.

[MattT]

Thanks gents. Seeing in Melbourne is rubbish. A very good point though Wavy....this is more of a long term project, for the country move.... eventually. Think I'll hang out to see if I can get an Istar 8" f12 R35 lens from Istar, before I decide which way to jump.
A refractor is my first choice. The yolo design I haven't looked into, so thanks Rod.

[Satchmo]

Anything that uses torroidal elements to correct for inherent astigmatism kind of makes me cringe :)

I much prefer the Schupmann telescope if you want to build exotic designs..

http://www.willbell.com/tm/schupmann.htm

The late optician Bill James once showed me a 30" BK7 disc he intended as the primary objective for his Shupmann `retirement scope' . Unfortunately it ended up at Mt Stromlo and was destroyed in the 2003 fires .

It is primarily a refracting scope so that should tick the boxes for you Matt :)

[MattT]

Thanks Mark. I gotta a bit of research to do and should get along to the ASV instrument making section.
Of course first up is to put the 6" f12 on and use that for a while.
Matt