Maksutovs. Somewhere between reflectors and refractors?

[pipnina]

I already have a telescope and don't intend to get a new one for some time. But one of the options I had when buying it I may have overlooked- The maksutov.

Reading the Wikipedia article, it sounds like a great design- Removes spikes from reflectors and corrects spherical abberation and deals with minimal chromatic abberation.

However, I have no idea about the reality of these scopes. If they really were the great middle ground between reflectors and refractors, surely they'd be much more popular than they appear from my perspective. Also, they must have SOME downside. Else, again, they'd be everywhere.

Can someone who knows more about them help me out?

(This is somewhat related to my interest in different variations of the reflector design, especially off-axis reflectors.)

    ~pipnina

[michael.h.f.wilkinson]

Typically the downside is the long focal length, and therefore small field of view

[John]

There are several designs of maksutov, the most commonly found are the maksutov-cassegrains followed by the maksutov-newtonians. I've owned both types but particularly found the maksutov-newtonian a versatile design that can have a reasonably short focal length and still produce refractor like images. Their downsides are that they tend to be heavy for their aperture, take quite a time to fully cool down and are quite costly. Michael has outlined the downside with the maksutov-cassegrain design.

[ronin]

They are a compound and one of them, either SCT or Mak is really a "reflector" as the front plate is flat and holds the second mirror in place - that mirror being spherical not flat. So in effect 2 mirrors.

On the other the front plate is a corrector so it does something and is closer to the term "compound".

Maks tend to be about f/13 to f/15 whereas SCT's are seemingly f/10.

To focus either it seems normal to move the mirror forward and backwards and not to move the eyepiece.

Keep reading they are supposed to deliver pin sharp images, but never actually experienced this feature in use. Not sure why but my refractors seem to be sharper.

As mentioned they tend to have long focal lengths and therefore a fairly narrow field of view, may not sound much but the reality is otherwise. Any object drifting tends therefore to drift out quick. They are better on a goto then manual. With a long focal length getting a low magnification can be a problem.

[dweller25]

I really like Maks - the planetary views through them are close to refractor views BUT you have to consider cooldown.......

Intes Micro make excellent Maks with the best cooling solution going - the front corrector is surrounded by vent holes through which air is pulled through the scope to the rear and over the mirror - which removes the boundary layer - perfect.

I would not buy a Mak without active cooling.

[pipnina]

There are several designs of maksutov, the most commonly found are the maksutov-cassegrains followed by the maksutov-newtonians. I've owned both types but particularly found the maksutov-newtonian a versitile design that can have a reasonably short focal length and still produce refractor like images. Their downsides are that they tend to be heavy for their aperture, take quite a time to fully cool down and are quite costly. Michael has outlined the downside with the maksutov-cassegrain design.

They are a compound and one of them, either SCT or Mak is really a "reflector" as the front plate is flat and holds the second mirror in place - that mirror being spherical not flat. So in effect 2 mirrors.

On the other the front plate is a corrector so it does something and is closer to the term "compound".

Maks tend to be about f/13 to f/15 whereas SCT's are seemingly f/10.

To focus either it seems normal to move the mirror forward and backwards and not to move the eyepiece.

Keep reading they are supposed to deliver pin sharp images, but never actually experienced this feature in use. Not sure why but my refractors seem to be sharper.

As mentioned they tend to have long focal lengths and therefore a fairly narrow field of view, may not sound much but the reality is otherwise. Any object drifting tends therefore to drift out quick. They are better on a goto then manual. With a long focal length getting a low magnification can be a problem.

Hmmm. Maybe I should look into these when I eventually upgrade my current scope.

These two (Of the different types) are confusing me...

Because this:

www.wexphotographic.com/buy-sky-watcher-skymax-180-pro-maksutov-cassegrain-ota/p1524368?cm_mmc=googlebase-extension-_-telescopes-_-catadioptric-telescopes-_-sky-watcher-skymax-180-pro-maksutov-cassegrain-ota_1524368&utm_source=googlebase-extension&cm_mmc=google+-+warehouse+cameras+%26+lenses-_-shopping+-+other+products-_-&mkwid=430wvtp4&pcrid=54652739529&gclid=cjwkeaiaymcnbrda0pyex-qswb0sjadknmkaom4rpapqoi0kkjhyfe_jgjdzbdxlxpiywuboklkevbocqvzw_wcb

Apparently has a longer focal length than this:

http://www.wexphotographic.com/buy-sky-watcher-explorer-190mn-ds-pro-maksutov-newtonian-reflector-ota/p1524492?cm_mmc=googlebase-extension-_-telescopes-_-reflector-telescopes-_-sky-watcher-explorer-190mn-ds-pro-maksutov-newtonian-reflector-ota_1524492&utm_source=googlebase-extension&cm_mmc=google+-+warehouse+cameras+%26+lenses-_-shopping+-+other+products-_-&mkwid=430wvtp4&pcrid=54652739529&gclid=cjwkeaiaymcnbrda0pyex-qswb0sjadknmka5vqfyfmhtjrnug-o2syldtthe9izkbvdtjmiwjxdxhocvkvw_wcb

I presume it has something to do with the corrector at the front?

[nightfisher]

I am a fan of the Maksutov, but as said they do need a bit of time for cooling, they can be a little on the heavy side and do have a narrow field of view, i use a 150 pro and it works nice with revelation 42mm 2" eyepiece, giving a fairly low x42.5 mag, these scopes tend to be used mainly for planet and lunar work, though i have had some superb views of M42 with an OMC140 mak

[pipnina]

Hmm. Is it just me, or do newtonian maksutovs not exist past 7.5 inches?

Could this be because of difficulty producing the lens at the front for large apertures?

[nightfisher]

Hmm. Is it just me, or do newtonian maksutovs not exist past 7.5 inches?

Could this be because of difficulty producing the lens at the front for large apertures?

These are very heavy and over 7.5 they may become rather difficult to mount

[pipnina]

These are very heavy and over 7.5 they may become rather difficult to mount

Hm. I guess that would cause a problem.

Wait, wouldn't they (even the newtonians) be unable to take CCD images?

[DaveS]

Any mak can have a CCD attached, field of view depends on chip size and FL. The 190 Mak-Newt has a very good reputation as an astrograph, but needs fettling but at f/5.3 it's pretty fast and 1000 mm FL will give a decent image scale. It needs a pretty good mount (NEQ6 absolute minimum) because of the huge moment arm.

The 180 Mak-Cass has a reputation as a planet killer, but it's f/15 and 2700 mm FL. it *can* be used on DSOs but you need to select your target with care. you can also run it on a HEQ5 due to the more compact tube.

[pipnina]

Any mak can have a CCD attached, field of view depends on chip size and FL. The 190 Mak-Newt has a very good reputation as an astrograph, but needs fettling but at f/5.3 it's pretty fast and 1000 mm FL will give a decent image scale. It needs a pretty good mount (NEQ6 absolute minimum) because of the huge moment arm.

The 180 Mak-Cass has a reputation as a planet killer, but it's f/15 and 2700 mm FL. it *can* be used on DSOs but you need to select your target with care. you can also run it on a HEQ5 due to the more compact tube.

I thought sky-watcher's mounts stopped at EQ6?

[DaveS]

Beyond the EQ6 is the NEQ6 (Sort of pro version), then the AZ-EQ6 (A NEQ6 with the niggles ironed out) and the EQ8 with a serious load capacity, about double the cost of the NEQ6 and with some niggles of it's own. Beyond *that* you're into serious money and looking at £5k up.

Have a look here:

http://www.firstlightoptics.com/skywatcher-mounts.html

[John]

Hmmm. Maybe I should look into these when I eventually upgrade my current scope.

These two (Of the different types) are confusing me...

Because this:

www.wexphotographic.com/buy-sky-watcher-skymax-180-pro-maksutov-cassegrain-ota/p1524368?cm_mmc=googlebase-extension-_-telescopes-_-catadioptric-telescopes-_-sky-watcher-skymax-180-pro-maksutov-cassegrain-ota_1524368&utm_source=googlebase-extension&cm_mmc=google+-+warehouse+cameras+%26+lenses-_-shopping+-+other+products-_-&mkwid=430wvtp4&pcrid=54652739529&gclid=cjwkeaiaymcnbrda0pyex-qswb0sjadknmkaom4rpapqoi0kkjhyfe_jgjdzbdxlxpiywuboklkevbocqvzw_wcb

Apparently has a longer focal length than this:

http://www.wexphotographic.com/buy-sky-watcher-explorer-190mn-ds-pro-maksutov-newtonian-reflector-ota/p1524492?cm_mmc=googlebase-extension-_-telescopes-_-reflector-telescopes-_-sky-watcher-explorer-190mn-ds-pro-maksutov-newtonian-reflector-ota_1524492&utm_source=googlebase-extension&cm_mmc=google+-+warehouse+cameras+%26+lenses-_-shopping+-+other+products-_-&mkwid=430wvtp4&pcrid=54652739529&gclid=cjwkeaiaymcnbrda0pyex-qswb0sjadknmka5vqfyfmhtjrnug-o2syldtthe9izkbvdtjmiwjxdxhocvkvw_wcb

I presume it has something to do with the corrector at the front?

The maksutov-cassegrains have long focal lengths and slow focal ratios (eg: F/12, F/15 etc) wheras the maksutov-newtonians have shorter focal lengths and much faster focal ratios, eg: F/5 to F/8. The mak-cassegrains tend to be planetary imaging and viewing scopes wheras the mak-newtonians are pretty good at both planetary and deep sky. They are different designs conceived by the same designer, Dmitri Maksutov:

http://en.wikipedia.org/wiki/Maksutov_telescope

Both designs can be had in quite large apertures but the price escalates steeply when the aperture exceeds around 7 inches because of the optical and mechanical engineering involved. A 12" can set you back £10,000 plus

I've owned a Russian (Intes) 6" F/5.9 maksutov-newtonian and it was a lovely scope. The Skywatcher 190mm mak-newtonians can be bought for around £500-£600 on the used market and seem pretty good buys to me.

[pipnina]

Beyond the EQ6 is the NEQ6 (Sort of pro version), then the AZ-EQ6 (A NEQ6 with the niggles ironed out) and the EQ8 with a serious load capacity, about double the cost of the NEQ6 and with some niggles of it's own. Beyond *that* you're into serious money and looking at £5k up.

Have a look here:

http://www.firstlightoptics.com/skywatcher-mounts.html

The maksutov-cassegrains have long focal lengths and slow focal ratios (eg: F/12, F/15 etc) wheras the maksutov-newtonians have shorter focal lengths and much faster focal ratios, eg: F/5 to F/8. The mak-cassegrains tend to be planetary imaging and viewing scopes wheras the mak-newtonians are pretty good at both planetary and deep sky. They are different designs conceived by the same designer, Dmitri Maksutov:

http://en.wikipedia.org/wiki/Maksutov_telescope

Both designs can be had in quite large apertures but the price escalates steeply when the aperture exceeds around 7 inches because of the optical and mechanical engineering involved. A 12" can set you back £10,000 plus

I've owned a Russian (Intes) 6" F/5.9 maksutov-newtonian and it was a lovely scope. The Skywatcher 190mm mak-newtonians can be bought for around £500-£600 on the used market and seem pretty good buys to me.

I see. I think those may be my investment once I have enough money (ha).

[jimbo747]

I chose a mak 127 as

1) its portable and fairly light

2) its excellent on planets and most smaller DSO.

3) It will tolerate rubbish eye pieces where a fast refractor won't.

4) don't have to worry about collimation. And if you do, its far easier than a newt

Cool down only downside in winter as takes an hour, so I've bought a case and now put it in shed at lunchtime if it looks like it might be clear in evening.

[Tommohawk]

If you want a planetary type Mak there's a Skymax 180 pro in Penryn on Preloved right now.

[damnut]

meade used to do a 10" MNT. A friend  had one mounted o a skytee II on top of an AE pillar, it was a dso hunting machine. I now have this setup but a mak where the Meade MNT was!

I have a 150mm mak, and used to have a 10"lX200, they both take some cooling and the meniscus / corrector plates attract dew like flies to doggy doo!. I always use a dewshield

[pipnina]

meade used to do a 10" MNT. A friend  had one mounted o a skytee II on top of an AE pillar, it was a dso hunting machine. I now have this setup but a mak where the Meade MNT was!

Kit2_2.jpg

I have a 150mm mak, and used to have a 10"lX200, they both take some cooling and the meniscus / corrector plates attract dew like flies to doggy doo!. I always use a dewshield

Can you explain what dew is? Is it condensation on the scope?

I've never understood what people mean by 'dew' or why, if it is condensation, it actually winds up on/in the scope (Considering something has to be colder than the surroundings to condensate, right?)

[chiltonstar]

Another point in favour of Maks is the nearly flat field of view, unlike SCTs. Not having ghastly image artefacts (diff spikes) also helps for some of us, although there are folk out there who like them and some even paste them in to images apparently......

A downside for me is the relatively large central obstruction which reduces contrast and produces "fattened" diffraction rings around stars at high mag compared with fracs. These can make seeing a faint companion star in a complex system more difficult.

Chris

[pipnina]

Another point in favour of Maks is the nearly flat field of view, unlike SCTs. Not having ghastly image artefacts (diff spikes) also helps for some of us, although there are folk out there who like them and some even paste them in to images apparently......

A downside for me is the relatively large central obstruction which reduces contrast and produces "fattened" diffraction rings around stars at high mag compared with fracs. These can make seeing a faint companion star in a complex system more difficult.

Chris

Surely diffraction spikes have the potential to hide companion stars entirely? I'd rather have a small ring than spikes any day!

Also, if you look at many Hubble images, you can also see a sort of sharp ring around stars.

Example: http://www.wired.com/images_blogs/wiredscience/2009/10/phot-40c-09-fullres.jpg

[John]

meade used to do a 10" MNT. A friend  had one mounted o a skytee II on top of an AE pillar, it was a dso hunting machine. I now have this setup but a mak where the Meade MNT was!

Kit2_2.jpg

I have a 150mm mak, and used to have a 10"lX200, they both take some cooling and the meniscus / corrector plates attract dew like flies to doggy doo!. I always use a dewshield

The Meade scope is a schmidt-newtonian. Different design but it looks similar to a mak-newtonian. The schmidt-newtonians have relatively large secondary obstructions and are more for deep sky imaging I believe.