Skywatcher 12 inch Mak-Cass

[billdan]

This could be vapour-ware, but I believe it is in Beta testing.

Its being advertised on Teleskop-Austria website and costs Eu1999.00, they are taking pre-orders but no shipping date.

Specs
300mm primary
105mm secondary (35% obstruction)
Focal Length 3000mm (F10) or 2040mm (F6.8) with reducer
Weight 17Kg

[Atmos]

Shouldn't a Mak-Cass have a meniscus front lens?
If they've managed at 12" at under 20kg they've done either a very good job design wise or skimped a bit.

[billdan]

I don't know what the rules are for a Mak-Cass (meniscus corrector??).

It appears to have a crayford focuser (from the photo) so I imagine the primary is fixed and does not move like a conventional Cass.

[DarkArts]

It's a Ruland Maksutov-Cassegrain (hence 'R-Mak') rather than a more usual Gregory Maksutov-Cassegrain.

A Gregory Mak-Cass does indeed have a 'spot' secondary on the corrector, whereas the R-Mak has the corrector in front of the secondary - a sub-aperture corrector. This SkyWatcher design also another corrector in the baffle tube, apparently. The R-Mak is an open-tubed design unlike the Gregory Mak-Cass.

There are other variations on the Mak-Cass, such as the Rutten Maksutov (Rumak) with the secondary separate from the corrector.

There's a Cloudy Nights article on the SkyWatcher R-Mak here:
https://www.cloudynights.com/topic/556722-new-skywatcher-maksutov-300mm/

And, of course, wikipedia:
https://en.wikipedia.org/wiki/Maksutov_telescope

A long time ago, I owned a humble Gregory Mak-Cass. At f/15, it was a surprisingly good scope for casual viewing - very forgiving of eyepiece under-performance.

[croweater]

Hi guys, my little vixen vmc95l mak cass has a corrector in front of the secondary.
Cheers Richard.

[billdan]

@DarkArts

Thanks for that Cloudy Nights link, I learnt a lot more about Mak-Cass's.

However this was discussed in Nov 2016 and still no production models, so they either are having problems or lost interest for a couple of years.

What impressed me was that its designed to provide a 62mm fully illuminated flat field at F10, and a 42mm flat field with the reducer. So its been designed to take a full frame camera.
The back focus is 330mm so it can accommodate a lot gear behind the focuser.

[netwolf]

Reminds me of the TAL 150K and 200K Klevtsov-Cassegrain a modified Maksutov.

[glend]

In reading the Cloudy Nights thread concerning this scope, it does contain enough info to create interest. There was mention of more details in a French forum. I noticed that the US Skywatcher rep that hangs out on CN (Skyward Eyes), said it "was still not ready for release", which sounds like he is confirming it is real, and likely being Beta tested by a few select testers that Skywatcher USA uses.
Honestly, it is a really bad time to hit the market with a new scope, and their principle market (USA) now has 26 million unemployed. Timing is everything. I suspect they will sit on this scope for at least 12 months.

And I agree that photo suggests the central obstruction is much bigger than claimed. Read about it here:


https://www.cloudynights.com/topic/703963-skywatcher-ruland-r-mak300-12-f10-cassegrain/

I am more than happy with my new 8" GSO f12 Classical Cassegrain, my credit card is safe.

Also here is the link to the Austrian Teleskop site which is taking pre-order (note this is not Teleskop-Express, aka TS): Choose the En (English) page at the top.

https://teleskop-austria.at/SWRMAK300

Others you could consider: the 10" GSO f12 Truss Cassegrain, which is already selling in Australia for $3999. If it is designed like my 8", then no coma and fairly flat field.

[ariefm71]

A Mak with spikes shouldn't be called a Mak-Cass (yes, I read that wiki page). Vixen version of this exact design (VMC200L/VMC260L) are not selling well. I don't think this will see the light of day

Arief