With some buying and selling you could trade up, there’s quite a nice very collectible example of Zeiss minimalism on AM, fully functional with all accessories and original box in East German communist hospital grey:
Please let me throw a bucket of cold water over this thread before it generates another Maksutov hype.
Back in the nineties I got sucked into one and made a 7.5" Gregory Mak.
Well it turned to be so temperamental regarding thermal control, that I moved on to a DK planetary not long after.
I won't go into details, but it is just about impossible to get a Mak working at it's theoretical limit for more than a few minutes in conditions of dropping temperature.
I know that there are not many big Mak's out there, but I've never seen cutting edge planetary images made with one. Has anyone?
And the trick of insulating the OTA - which no doubt seems heretical to many - works a treat on this scope.
I can confess I am toying with the idea of putting an ASI128 or ASI071 on mine as it has a clear 48mm image circle.
Yes, this is turning into a bit of a Mak love-fest... A bucket of cold water is a good thing.
Had you insulated your Mak?
The thermal issue is a very real one as you say. Letting closed-tube Cats cool is a confounded problem, with the largest of Cats just refusing to play nice, especially when big temperature differentials exist between starting temp and the ambient temp however much time later. Unless the scope is kept in a cold room, there will always be thermal issues with closed-tube Cats. We've been forcing closed-tube Cats to cool in attempt to force them to behave more like open tube scopes and even refractors. Maybe closed-tube Cats require a different thermal approach.
A few questions are brought up this way. Why are Maks not popular for photo? Thermal issues? Expense? Bad press? Being Russian in origin? Ignorance? I for one had avoided Maks for many years for many reasons: of following a perceived East vs West thing: being so exotic I didn't trust them: seeing that Maks were just about totally shunned in the popularity stakes of scopes: their very slow focal ratio vs the faster and faster trend: price may have been a big factor influencing this. Ignorance though is the one common factor in all of the above other than price. I certainly have changed my opinion about Maks.
Why has this visual quality not translated into photo as suggested? But there are some people who are using Maks, and large Maks at that, for some very high quality lunar and planetary photography. English language forums are the worst representatives for Mak photography too!!!
Insulating closed-tube Cats has made a big difference, especially for Maks. Open tube scopes are a totally different thermal proposition. But with this change in now insulating Maks, maybe it will see a return to Maks for photo? Maybe Maks, and SCT's, needed a different take way of dealing with their thermal characteristics, to which the traditional "cooling" ones are not best practice for them. And insulating them is the trick to slow their cooling rather than forcing a cooling process. This requires a BIG change in the conventional thinking about how to deal with heat in scopes, and how many people will be willing to accept a change in thinking?
Last edited by mental4astro; 06-04-2019 at 02:31 PM.
Don’t see a problem with a love-fest, so long as we don’t lose perspective. It’s always nice to dream
A glint of the perspective is that there are few of these in Australia making them somewhat unobtainium. Where’s the fun in bragging rights when you can’t share the love?
Regardless of their magical qualities, mass-produced SCTs are just plain easier to get hold of, in Australia or otherwise, and more gentle on the wallet.
Then there’s the paradigm of resolution in lucky imaging. Getting a good enough SCT just isn’t that hard. I can’t imagine SE QLD is that unique, but I know a number of folk with good scopes - all of which I’ve looked through. My own scopes I don’t regard as particularly special, but the results speak for themselves.
Planetary imaging comes down as much to robust technique as anything, other than the seeing of course. A common weapon of choice is a C14...not outrageously expensive, relatively lightweight, a lot of light grasp and easy to reach the realm of high resolution planetary imaging with a simple 2x Barlow.
When we start talking deep sky imaging, Maks are just too slow. SCTs too. Imagers don’t chose to image at f/10. This is what makes larger newts, with all their flaws, more appealing as it’s not hard to get a seeing-limited focal length in the region of f/4-5. Advances in sensor technology open up reasonable exposure times to slower scopes, but faster f-ratio will always have the upper hand.
Theoretical superiority is one thing, but practical accomplishments are another...
I would not call the linked images cutting edge, for 230 mm aperture, but I was thinking along custom built Maks. There must be some larger aperture ones out there but no results to show.
What sets the Mak apart from other Cats is the very thick front lens and that is its undoing. Insulating the tube may resolve internal thermal gradients, but if the front lens is above or below ambient, it will have a proximity layer, on the exposed surface, messing with its performance. Though, it won't be as severe as the one caused by the proximity layer on a primary mirror because in case of a mirror the light goes through it twice.
And these are expensive scopes and people should not be sucked into hypes based on subjective comments - like I was.
Please do not evaluate a Mak against another Mak. Do it against a similar aperture, but good, Newtonian using similar magnification - you may be surprised.
Last edited by Stefan Buda; 07-04-2019 at 06:53 AM.
I ended up cutting two large holes into opposite sides of the CF tube for ventilation. That helped but as soon as the front would reach thermal equilibrium, it would start fogging up.
Another experiment I did, was to store the scope in a cold place during the day and then take it outside to look at Jupiter exactly when the ambient temperature crossed over the scope's storage temp. The view, needles to say, was excellent but lasted less than 10 minutes.
Don’t see a problem with a love-fest, so long as we don’t lose perspective. It’s always nice to dream
A glint of the perspective is that there are few of these in Australia making them somewhat unobtainium. Where’s the fun in bragging rights when you can’t share the love?
Regardless of their magical qualities, mass-produced SCTs are just plain easier to get hold of, in Australia or otherwise, and more gentle on the wallet.
Then there’s the paradigm of resolution in lucky imaging. Getting a good enough SCT just isn’t that hard. I can’t imagine SE QLD is that unique, but I know a number of folk with good scopes - all of which I’ve looked through. My own scopes I don’t regard as particularly special, but the results speak for themselves.
Planetary imaging comes down as much to robust technique as anything, other than the seeing of course. A common weapon of choice is a C14...not outrageously expensive, relatively lightweight, a lot of light grasp and easy to reach the realm of high resolution planetary imaging with a simple 2x Barlow.
When we start talking deep sky imaging, Maks are just too slow. SCTs too. Imagers don’t chose to image at f/10. This is what makes larger newts, with all their flaws, more appealing as it’s not hard to get a seeing-limited focal length in the region of f/4-5. Advances in sensor technology open up reasonable exposure times to slower scopes, but faster f-ratio will always have the upper hand.
Theoretical superiority is one thing, but practical accomplishments are another...
Then there is the plain fact that, despite whatever scope you may own, Nick will always come in to tell you that his Santel is better! 😀
Yes, this is turning into a bit of a Mak love-fest... A bucket of cold water is a good thing.
Had you insulated your Mak?
The thermal issue is a very real one as you say. Letting closed-tube Cats cool is a confounded problem, with the largest of Cats just refusing to play nice, especially when big temperature differentials exist between starting temp and the ambient temp however much time later. Unless the scope is kept in a cold room, there will always be thermal issues with closed-tube Cats. We've been forcing closed-tube Cats to cool in attempt to force them to behave more like open tube scopes and even refractors. Maybe closed-tube Cats require a different thermal approach.
A few questions are brought up this way. Why are Maks not popular for photo? Thermal issues? Expense? Bad press? Being Russian in origin? Ignorance? I for one had avoided Maks for many years for many reasons: of following a perceived East vs West thing: being so exotic I didn't trust them: seeing that Maks were just about totally shunned in the popularity stakes of scopes: their very slow focal ratio vs the faster and faster trend: price may have been a big factor influencing this. Ignorance though is the one common factor in all of the above other than price. I certainly have changed my opinion about Maks.
Why has this visual quality not translated into photo as suggested? But there are some people who are using Maks, and large Maks at that, for some very high quality lunar and planetary photography. English language forums are the worst representatives for Mak photography too!!!
Insulating closed-tube Cats has made a big difference, especially for Maks. Open tube scopes are a totally different thermal proposition. But with this change in now insulating Maks, maybe it will see a return to Maks for photo? Maybe Maks, and SCT's, needed a different take way of dealing with their thermal characteristics, to which the traditional "cooling" ones are not best practice for them. And insulating them is the trick to slow their cooling rather than forcing a cooling process. This requires a BIG change in the conventional thinking about how to deal with heat in scopes, and how many people will be willing to accept a change in thinking?
Don’t see a problem with a love-fest, so long as we don’t lose perspective. It’s always nice to dream
A glint of the perspective is that there are few of these in Australia making them somewhat unobtainium. Where’s the fun in bragging rights when you can’t share the love?
Regardless of their magical qualities, mass-produced SCTs are just plain easier to get hold of, in Australia or otherwise, and more gentle on the wallet.
Then there’s the paradigm of resolution in lucky imaging. Getting a good enough SCT just isn’t that hard. I can’t imagine SE QLD is that unique, but I know a number of folk with good scopes - all of which I’ve looked through. My own scopes I don’t regard as particularly special, but the results speak for themselves.
Planetary imaging comes down as much to robust technique as anything, other than the seeing of course. A common weapon of choice is a C14...not outrageously expensive, relatively lightweight, a lot of light grasp and easy to reach the realm of high resolution planetary imaging with a simple 2x Barlow.
When we start talking deep sky imaging, Maks are just too slow. SCTs too. Imagers don’t chose to image at f/10. This is what makes larger newts, with all their flaws, more appealing as it’s not hard to get a seeing-limited focal length in the region of f/4-5. Advances in sensor technology open up reasonable exposure times to slower scopes, but faster f-ratio will always have the upper hand.
Theoretical superiority is one thing, but practical accomplishments are another...
Another great post!
There is nothing magical about these Maks that should see anyone feel they are SOOOOO much better than a large SCT. Sure, I’m happy with mine but, for the price I paid, I’d sure well want to be. Is it exponentially worth the difference between its cost and that of a much larger SCT... I’m not sure, I don’t own the latter. I imagine not....
I ended up cutting two large holes into opposite sides of the CF tube for ventilation. That helped but as soon as the front would reach thermal equilibrium, it would start fogging up.
Another experiment I did, was to store the scope in a cold place during the day and then take it outside to look at Jupiter exactly when the ambient temperature crossed over the scope's storage temp. The view, needles to say, was excellent but lasted less than 10 minutes.
Very interesting, Stefan.
Would you say that these scopes are best suited to Summertime (or, at least warmer climate) viewing?
Yes, this is turning into a bit of a Mak love-fest... A bucket of cold water is a good thing.
Had you insulated your Mak?
The thermal issue is a very real one as you say. Letting closed-tube Cats cool is a confounded problem, with the largest of Cats just refusing to play nice, especially when big temperature differentials exist between starting temp and the ambient temp however much time later. Unless the scope is kept in a cold room, there will always be thermal issues with closed-tube Cats. We've been forcing closed-tube Cats to cool in attempt to force them to behave more like open tube scopes and even refractors. Maybe closed-tube Cats require a different thermal approach.
A few questions are brought up this way. Why are Maks not popular for photo? Thermal issues? Expense? Bad press? Being Russian in origin? Ignorance? I for one had avoided Maks for many years for many reasons: of following a perceived East vs West thing: being so exotic I didn't trust them: seeing that Maks were just about totally shunned in the popularity stakes of scopes: their very slow focal ratio vs the faster and faster trend: price may have been a big factor influencing this. Ignorance though is the one common factor in all of the above other than price. I certainly have changed my opinion about Maks.
Why has this visual quality not translated into photo as suggested? But there are some people who are using Maks, and large Maks at that, for some very high quality lunar and planetary photography. English language forums are the worst representatives for Mak photography too!!!
Insulating closed-tube Cats has made a big difference, especially for Maks. Open tube scopes are a totally different thermal proposition. But with this change in now insulating Maks, maybe it will see a return to Maks for photo? Maybe Maks, and SCT's, needed a different take way of dealing with their thermal characteristics, to which the traditional "cooling" ones are not best practice for them. And insulating them is the trick to slow their cooling rather than forcing a cooling process. This requires a BIG change in the conventional thinking about how to deal with heat in scopes, and how many people will be willing to accept a change in thinking?
Is this problem not the reason why scopes such as my Edge HD Celestron have tube vents
Is this problem not the reason why scopes such as my Edge HD Celestron have tube vents
Yes, Jeremy.
This solution follows the conventional thinking around forcing scopes to cool. And while in principle it works, it is not necessarily best practice, but as a selling point it is excellent because this is what people know and expect. It still requires a waiting time and constant monitoring.
Yet the insulation route is totally passive.
Dew formation is a separate matter though. All scopes are susceptible to it, thought needs to go into it, and designed specifically for each scope type, though the principles followed are the same.
As for dealing with dew, one has three options: 1, heating strap around the corrector -not my favourite as you want the scope to cool (slowly or quickly) and then a heat source is re-introduced around an active lens element: 2, rig up a blower system that will evaporate dew, either heated (care needed), or at ambient temp: 3, set up scope at a dew-free location - dew and astro ARE NOT inseparable bed fellows. The dark site location my observing buddies and I use, we are still to experience a night of any dew on our optics in now more than 7 years, a on all types of scopes, Maks included. All about site selection and time into these investigations. Dew-free astro is possible.
One thing I don't want to do is create the impression that I'm saying Maks are the perfect scope. They are not, in the same way no particular scope design is. Maks fill a niche and it is up to the individual to figure out if a Mak satisfies a particular requirement they have. I have some 14 scopes, of these only one Mak, and I still have an SCT as IT fills a niche for me with outreach. And yes Dunk, I do agree with practices being equally important to extract the very best from whatever scope one is using, both photo and visual.
Alex.
Last edited by mental4astro; 07-04-2019 at 10:08 AM.
......I want it..... NOW ..!!
