8” Classical Cassegrain vs Skymax 180

[johninderby]

Have been wondering how these two scopes compare. 

The Cassegrain has more aperture and no meniscus lens and should cool down faster and has a crayford focuser and a fixed primary. Made by GSO and the same as the TS and Orion versions. 

Omegon Cassegrain Pro CC 203/2436 OTA

https://www.omegon.eu/telescopes/omegon-cassegrain-telescope-pro-cc-203-2436-ota/p,61487

However not a lot of reviews out there although the few do seem positive. I mean I like my Skymax 180 but would there be any advantage in changing it for the classical Cassegrain. .

Hmmmmmmm 🤔

Edited October 6, 2019 by johninderby

[Alan White]

John, you must resist.

That AZ100 really does have your name on it 😃

But if you want to try it with a Cassegrain, it would be interesting to find out.

[johninderby]

If I went for the Cassegrain would sell the Skymax 180 and if I don’t get the encoders for the AZ100 and the cash from the TS-AZ5 mount would nearly pay for it.

[Alan White]

I think I spied the Mak in the For Sale section John,
so take it you have decided to give one a try?

 

[johninderby]

1 minute ago, Alan White said:

I think I spied the Mak in the For Sale section John,
so take it you have decided to give one a try?

 

Yes I have. Similar size and weight OTA as the Mak and well just interested me. 🤔

[Alan White]

Sounds like an itch that needed a scratch.
I wish you well with it, be interested to hear how it works out.
I have an inkling that it will go very well.

 

[johninderby]

Felt like trying something a bit different.

To quote Robert Frost

“Two roads diverged in a wood and I - I took the one less traveled by, and that has made all the difference.”

[dweller25]

This is the latest review i can find....

astromart.com/reviews-and-articles/reviews/telescopes/cats/show/gso-8-inch-true-cassegrainian

 

[johninderby]

Thanks for the link. Confirms my opinion that the 8” cass will be a bit better than the 180 Mak. Sounds like a great all round performer with less priblems with changing temps. 👍🏻

Edited October 7, 2019 by johninderby

[Stu]

Certainly sounds and looks promising John. I guess similar in a certain way to the Mewlon 210 I have?

[johninderby]

A cheaper alternative. 🙂

Sort of halfway between the Skymax and the Mewlon? 🤔

Edited October 7, 2019 by johninderby

[Stu]

15 minutes ago, johninderby said:

A cheaper alternative. 🙂

Sort of halfway between the Skymax and the Mewlon? 🤔

That probably sounds about right. The Mewlon has an oversized primary so is presumably 'full aperture', plus probably better figured or at least more consistently figured optics. Hopefully you will enjoy the scope, a nice alternative to the usual options.

[johninderby]

Manual for the Orion branded version.

https://nimax-img.de/Produktdownloads/62478_1_Anleitung-EN.pdf

[johninderby]

While googling Cassegrain came across this. Not exactly what I was looking for even if it is a Cassegrain. 😳

[Stu]

5 minutes ago, johninderby said:

While googling Cassegrain came across this. Not exactly what I was looking for even if it is a Cassegrain. 😳

No, I don't suppose you would be very 'a pea' about that if it turned up.

Perhaps I'm in the wrong thread? 😉

[johninderby]

Interesting review of the TS version. See the second review by Guus Gilein, said he will be doing a shootout with a 210 Mewlon  but nothing yet that I can find.

https://www.teleskop-express.de/shop/product_info.php?products_id=10753#cs

[JeremyS]

58 minutes ago, johninderby said:

While googling Cassegrain came across this. Not exactly what I was looking for even if it is a Cassegrain. 😳

Nobody could ever accuse you of kicking the can down the road, John

🙂

 

[johninderby]

Black or white. 🤔

After double checking the prices find Telescope Express is a few pounds cheaper but shipping is slightly more. Only 3 quid more for the TS but shipping by DPD so I’ll know exactly when it’s arriving. 

Edited October 7, 2019 by johninderby

[dweller25]

White 👍

[johninderby]

White is “classical” isn’t it. 🙂

OTA has a Losmandy plate on one side and a Vixen on the other. Will be bolting a carry handle on to the  Vixen dovetail..

Edited October 7, 2019 by johninderby

[JeremyS]

White, definitely

[johninderby]

Now just to get the Mak sold. 🙏🏼

[chiltonstar]

How significant are coma and astigmatism with the Omegon in practice - any good practical assessments from "discerning users"?

As it is a classical cassegrain design, presumably there are diffraction spikes as well?

Chris

Edited October 8, 2019 by chiltonstar

[johninderby]

Coma and astigmatism don’t seem to ba any problem from the reviews I have read. It seems to be really well corrected. 

As it’s really a lunar & planetary scope spikes are a non issue but only seem to be present on very bright stars.

Edited October 8, 2019 by johninderby

[chiltonstar]

1 hour ago, johninderby said:

Coma and astigmatism don’t seem to ba any problem from the reviews I have read. It seems to be really well corrected. 

As it’s really a lunar & planetary scope spikes are a non issue but only seem to be present on very bright stars.

But aren't the deficiencies of a classical cassegrain design addressed with evolved designs like the Rumak (eg 180 Mak)? Maybe modern optical materials have improved classical cassegrains?

Chris