Opinion Please for Next Scope

On Wednesday, January 10, 2001 at 8:39:25 PM UTC-5, wrote:
John,

I really see myself as more concerned with optical performance, with
photography as an aside. I would be very bummed if I sold my nice dob,
and bought into poorer planetary views.

Rather than a large apo, have you considered maks and/or mak-newts ?
The small obstruction and aspheric correction of the mak=newt sounds
like a winner.

Thank again,

John

By the way, A Maksutov does not have an aspheric corrector. The corrector is spherical which gives it a cost advantage.

http://www.richardfisher.com

On 21/01/2016 21:58, Helpful person wrote:
On Wednesday, January 10, 2001 at 8:39:25 PM UTC-5, wrote:
John,

I really see myself as more concerned with optical performance, with
photography as an aside. I would be very bummed if I sold my nice dob,
and bought into poorer planetary views.

Rather than a large apo, have you considered maks and/or mak-newts ?
The small obstruction and aspheric correction of the mak=newt sounds
like a winner.

Thank again,

John

By the way, A Maksutov does not have an aspheric corrector.
The corrector is spherical which gives it a cost advantage.

Not really true. It is spherical *but* a Maksutov front plate corrector
is a deep curve requiring a big chunk of clear glass. I have one and I
know an amateur who made one (with a bit of help from the Pilkington
glass research department where he worked). There is a heck of a lot of
glass to be ground out and two surfaces to be polished and figured.

Russian made 10" Mak OTAs go for around $10k today and their cost scales
roughly with the square of the aperture. eg

http://www.apm-telescopes.de/en/tele...tov-cassegrain

You won't find a cheap Maksutov that is any good. They are intrinsically
expensive to manufacture to a decent quality.

By comparison there is a vacuum deform and then polish to flat trick
that can be used to make the Schmidt corrector plate which is why they
have become so cheap to mass produce. Compared to making a Maksutov
corrector plate the SCT mass production trick is a doddle.

https://en.wikipedia.org/wiki/Schmidt_corrector_plate

New 10" SCT kit complete with goto mount would set you back $3.5k and
you could probably find one on sale secondhand for about $2.5k.
(and you might well be better with an 8" for $2.5k new at first)

http://www.meade.com/products/telescopes/lx200.html

A 10" Meade LX200 scope is only an easy lift if you eat three shredded
wheat for breakfast. It is harder when your fingers are cold.

And the LX90 is about $1k cheaper still.

http://www.meade.com/products/telescopes/lx90.html

Basically you pays your money and you takes your choice.

--
Regards,
Martin Brown

On Friday, January 22, 2016 at 4:09:13 AM UTC-5, Martin Brown wrote:

A 10" Meade LX200 scope is only an easy lift if you eat three shredded
wheat for breakfast.

The scope only weighs about 70 lbs, gurrly mahn!

It is harder when your fingers are cold.

Don't forget your mittens.