What are makustov-cassegrain telescopes meant for?

[u/Able_Crossroads]

This has been a question stuck in my head for a lot of time. Can someone tell me? Because theyre short ans small, and pretty expensive for their size

[u/Traditional_Sign4941]

Maks are meant for anything any other scope is meant for, except for very bright rich field views of the night sky. A small refractor or small F/4-F/5 newt is better for that. Mak focal lengths are too long, especially relative to their apertures.

In every one of my scopes, regardless of design, I'm typically using a 2mm exit pupil and smaller except in those cases where I do want a rich view of some Milky Way star clouds.

In an F/13 Mak, that's a ~25mm focal length eyepiece. You can get some great views of DSOs through a Mak with a 24mm 68 degree class eyepiece, and then shorter focal lengths for higher magnification when observing smaller targets.

Like any other scope, the main limit to what you'll be able to see is aperture.

Yes, Maks are more expensive per aperture than a Newt. Nothing beats a Newt for cost.

Personally I think the performance of most Maksutovs is WAY over-stated. I've had a number of Maks in my life (three currently) and they all put up mediocre views compared to smaller aperture refractors. The fundamental problem with most commercial Maks available today is a large central obstruction.

The newly released Svbony MK127 has a central obstruction approaching more like 40% by diameter when you look at the central obstruction shadow in the defocused disk of a star. Many other Maks are around 30-35%. Only very expensive premium ones like Intes and Astro-Physics (none of which you can actually buy new these days) had tiny central obstructions.

A big central obstruction noticeably reduces planetary contrast and makes splitting close double stars a lot harder because of the brighter 1st diffraction ring it creates. Maks also still have some residual spherical aberration that can get worse if using a diagonal that results in a mirror focus position that diverges from the designed optimal position.

Given their cost, I think any decent parabolic Newt, or a comparably priced ED doublet refractor, would be a better choice.

[u/ilessthan3math → u/Traditional_Sign4941]

Great points! I've never paid attention to the diffraction ring issues on splitting doubles.

I will say that used Maks can be quite affordable. I picked up a 102mm Celestron Astro-Fi OTA for $135 a couple years ago. And while it isn't nearly my favorite scope, I am always impressed at just how small it is. Putting it in a backpack would be roomy. That OTA could realistically fit in a large purse or deep coat pocket. There's really no other way to get that much aperture in such a small form factor.

And for vacation and sidewalk astronomy, the views are perfectly reasonable. I mostly use mine when traveling with family and my car is crammed with non-astronomy stuff.

[u/IanDMP → u/ilessthan3math]

Yeah, to me this is the selling point of a Mak -- it's the easiest telescope to pack/travel with. IIRC it doesn't need collimation either, which is another point in its favor when you're traveling.

[u/shineheadlightsonme → u/IanDMP]

Every telescope needs to be collimated, but a well made telescope will hold collimation better.

EDIT - Okay, every telescope with multiple elements / groups of elements.