New telescope design idea

[mdstuart]

Create an F5 scope but work back from a cheap wide angle lens.

So figure the mirror so that the stars WILL be points right at the edge of the FOV and then figure the mirror so that the stars are also points at the centre.

Result...no need for expensive parrcorrs, no need for posh Naglers and Televues, stunning results.

Mark

Copyright of idea M.Stuart:glasses1:

[Paxo]

You can do this by using two hyperbolic mirrors to produce the flat field you are talking about. The downside is configuring hyperbolic mirrors is more expensive than the other gear you are talking about.

Steve..

[ronin]

Figuring mirrors to improve them and get a better profile is not unknown, they don't turn out perfect mirrors for the scopes in Hawaii and The Canaries from a production line. It is simply that the cost is disproportionately high.

Suspect that a hand figured mirror, even of amateur use size, will cost several thousand pounds.

Mechanical intolerances prevent mass production.

Original post says: work back from a cheap wide angle lens, then it says figure the mirror. Are we working on a lens or a mirror?

[Macavity]

I think there are some interesting (amateur even) scope ideas one might explore, where LARGE (20-30"!) "simple" light-gathering lenses are used, but corrected with medium size optics, somewhere in the middle of the scope?

Perhaps some are familiar with the HANWELL 30" (Dialyt) refractor? I was WELL impressed tho!

There was a lot of ex-Govt stuff (lenses and mirrors) I used to DREAM about in the early 70s. Notably one 9" F4 astro-camera - Not sure my post office savings would've stretch that far... or that my MUM would have fancied it around the house.

[barkis]

There's no way you can figure a fast mirror to bring all parallel light to the same focus. You need a correctors help too.

Ron.

[mdstuart]

Clearly as they say nothing is ever simple. I was just pondering why???

Thanks for the responses, very interesting.

Mark