Seeking help locating specific Maksutov scopes

[mental4astro]

Special permission has been sought and granted by the mods for what is a duplicate thread to the Wanted ad I have. Many thanks to the mods for allowing this.

Wanted: Intes Maksutov, or SW or Meade (http://www.iceinspace.com.au/forum/showthread.php?t=169158)

Hi all,

I am trying to locate some very specific Maksutov scopes in the hope of acquiring one of them. These are rare scopes, and as a result I have encountered difficulties trying to locate them.

Of special interest to me are the Intes Maks, in particular the 715 and 815 (the 7 refers to the aperture size in inches, the 15 the focal ratio). The 703 & 809 (both f/10) being second preference due to the larger secondary obstruction.

I would also consider a Skywatcher 7" Mak or a Meade 7" Mak, but I would want to do a star test on these. With the Meade Mak, it is the OTA I am after - as the fork mounts that these came on most likely are stone-cold-dead, their fork mounts are of no consequence. The star test of these would need to be superb.

In my original ad I've asked about 8" SCTs, these too would need to go through a star test by me first, and again superb to rival an Intes Mak.

It has also been suggested to me to consider a Takahashi Mewlon. However, as these have the mirrors exposed and because I live on the coast of Sydney, I'm trying to gather information about how suitable these scopes would be for me as whatever Cassegrain I end up with will be used pretty much exclusively from my home. All the same, any leads to a 180 or 210 Mewlon would also be appreciated as these are mighty fine instruments. To that end, if you have experience with these Tak scopes, I would appreciate it if you could share your experience about these scopes in following thread:

Couple of questions about Mewlons (http://www.iceinspace.com.au/forum/showthread.php?t=169553)


If you have any of the above scopes and would consider selling it, please let me know.

If you know of someone who has one of these scopes, and you feel like they may consider selling it, also please let me know and I can follow it up.

Many thanks for looking,

Alex.

[LewisM]

https://www.astronomy-electronics-centre.com.au/intesmicro.htm

[mental4astro]

Спасибо, Льюис :)

Buying new is last resort. I would like to first try to find a scope that isn't being used to give it a new lease on life. There is some fabulous glass out there that is just not being used.

Alex.

[glend]

Lewis, the links in that page do not work. Nor do the links on the Teleskop-services pages related to these products.

M_ludes from APM posted this notice about the future of Inter Micro on 3 July 2018:

https://www.cloudynights.com/topic/623980-maksutov-telescopes-future/

Note that currently APM seems to have a few of these scopes in stock. And APM state that they are planning to set up European production of these scopes in 2019.

[Wavytone]

There is a thread on CN that identified all the remaining makers of new maks 180mm or larger after the advice from APM. There are a few.

[mental4astro]

Anyone offer any further leads on who may have an Intes Mak?

Anyone have an Intes Mak that needs a new home?

Any Meade 7" Maks lying under a bed or in a garage?

I've decided not to pursue Mewlons. Might be a nice scope, but not the right instrument for where I live with its exposed mirrors.

Thanks for looking,

Alex.

[Wavytone]

Second time I’ve seen one of these on AM ... if you have deep pockets may as well go pick it up in person ... though you might need to go to the gym regularly to lift it, these are heavy:

https://www.astromart.com/classifieds/astromart-classifieds/telescope-catadioptric/show/tec-25020-mak-pick-up-only

[mental4astro]

Oooohhhh, drooooollllllll...

:atom::love::scared2::jump2:

I'll have two, please :) :drink:

[mental4astro]

Last stab in the dark in case there is someone who has one or knows of someone with one.

Thanks for looking,

Alex.

[dpastern]

Mak cass:

http://www.stellaroptical.com/cass.htm

Mak newt:

http://www.stellaroptical.com/newt.htm

i don't know if they have any in stock at the moment.

also:

https://www.teleskop-express.de/shop/index.php/language/en/cat/c74_Maksutov-Cassegrain-Telescopes.html

it doesn't look like TE has any in stock though from a very quick check. I could be wrong.

I've heard very good things about the SkyWatcher maks and AFAIK, they're still in production.

They do come up on Astromart from time to time.

hope this helps.

[dpastern]

Alex, another consideration is Astronomics is coming out with 6" and 8" Cassegrains (with larger scopes in the near future!). I believe they'll be f12 units, but could be wrong. There's a thread on CN about it.

[mental4astro]

TThanks for the suggestions, Dave.

I'd LOVE to have a 9" Santel. Wavytone has one, and OMG!!!

Drooooollllllll...

I've been bitten by the inability of being able to star test SCTs from retailers. The quality of these is not only unpredictable but the really good units are rare. They do exist, but unfortunately the exception than the norm. Now knowing the difference between exceptional optical quality (Wavy's Santel) and everything else, and what I want from the scope I'm using for my sketching, I'm not going down the new route - the price tag pf those Maks sold by Stellar Optical is just too prohibitive :(

So far I've had a few people offer their scopes to me. I have found two VERY bloody good scopes to far. A modest C8 (the OTA came from an old 8i outfit) & a Skywatcher 180mm Mak. I was able to see the Encke Division through both scopes! :eyepop: I returned the Mak ONLY because the slightly larger aperture of the C8 allowed me to see fainter stars, but optical quality wise I couldn't separate them. If anyone is interested in a rip-snortter and modestly priced Mak, let me know and I'll pass on the details.

I have kept the C8 for the rest of my testing period as I have a couple more C8's to test and I've found an Intes 715 Mak. Hoping a couple more scopes will be offered. I'm hoping to improve upon this first C8 with hopes to match that Santel.

I've returned a couple of other scopes too.

Alex.

[dpastern]

Sadly, Alex, I am not working, and have no money :( oherwise, I'd jump on a mak for planetary observing.

Still, I've had a lot of fun with my 6" dob in the past 6 or so weeks with planetary observing.

[mental4astro]

Whoops! :lol:

I poorly phrased that sentence! I was actually meaning if ANYONE wanted a good Mak I'd be happy to pass on the details of the person who's scope it belongs to! :lol: :rolleyes:

[mental4astro]

Thought I'd give final update to my search.

Thanks so much to all of you who generously lent me their precious scopes. Celestrons, Takahashis, Skywatchers and an Intes scope were all most graciously lent to me. I am truly honoured to have such trust put in me with such an array of instruments.

My star testing showed me a set of mighty fine instruments, and the faith that their owners have in them and why they were happy to have their scopes thrashed, so to speak... In the end it was an Intes 715 Deluxe that I have opted to keep.

If anyone is interested in getting their hands on one of the C8's and the Skywatcher Mak that I tested, let me know and I'll put you in contact with their owners. These were remarkably bloody good scopes! The Mewlon is being kept by its owner as its exposed mirrors I decided were not a good option for me as I live right next to the coast and with a constant sea breeze.

Below is a pic I took during one of the nights of testing. My good mate Wavy helped me out with this process. Cheers mate! :D

So, now I too have a Russian under my bed! :P

Alex.

[dpastern]

Congrats!

How much better was the Intes over the SkyWatcher Mak? The latter has a very good reputation.

[Wavytone]

Suffice to say the Intes 715D was clearly the pick of the bunch despite the state of the flocking - which will have to be removed.

The showdown was at 300X at which the other scopes were struggling, side by side on the same targets.

Mechanically the 715 also had perfect focussing with no slop whatsoever, and with the quality of its optics there is a very distinct snap when it reaches focus even at 300X and it suggests it could usefully go to insane magnifications - 360X or more on bright targets. Like my Santel and the Skywatcher maks, at first it may show a tube current, but that dies down soon enough and there is a known solution, anyway.

So at last Alex has a comrade to keep company with my Santel.

[dpastern]

ah cool..i wish i was working and could afford an Intes mak for planetary :-/

[raymo]

Just as a matter of curiosity, what would ball park prices be for these three scopes new?
raymo

[mental4astro]

What needs to be remembered is that seeing WAS poor this night. On nights of good seeing there was little separating these scopes. The poor seeing just showed that the photons in the Intes were a more tightly controlled in where they were directed (ultimately a better figure in the mirrors), so when seeing was challenging the image was less susceptible to seeing conditions.

Some scopes didn't cut the mustard at 250x. Those short listed scopes all did, and were not shy pushing 400X. The photo below is not of short listed scopes, just of one of our nights.

One key test was seeing the Encke Division in Saturn's rings.

Ray, which three scopes?

[LewisM]

Would you all stop copying MY signature line? Geez Louise...first Nick, now Alex.... there'll be a McCarthy-esque witch hunt at this rate!

No brainer that the best Maksutovs are made by Russians - even the TECs (seeing Yuri is expat Russian) :P

[mental4astro]

Wavy mentioned the focusing mechanism of the Intes.

Well blow me down! A cassegrain with a moving primary mirror for achieving focus, AND NO MIRROR SHIFT!

I couldn't believe it! Not a smidge of a shift. Nada, nothing, zip, zilch.

Takahashi Mewlon, Celestron, Meade, Skywatcher, take note: The Russians have done what you haven't, EVER, and they've been doing it for YEARS!

Oh, and with no mirror shift, collimation doesn't change with moving the focusing knob.

However, you do pay for all of this, no mirror shift and quality of optics.

Dave, the Skywatcher Maks I've seen have all been from very good to outstanding. And they've been improving over the years as the manufacturing techniques of the company that's making these Maksutov optics for Synta have been refined. How much better the Intes over the Skywatcher? If I hadn't known about the Intes, I would have happily settled for the Skywatcher 180 Mak. The quality of the SCTs, that's just too variable for me to buy new with no way of star testing first. Two of the SCT's we tested were bloody good, remarkable actually. And I'm quite fond of one of them too as it comes with a really nice fork mount that I love to use with my sketching... <sigh>

https://media.giphy.com/media/43tP7nc6VFQWs/giphy.gif

[raymo]

The Santel, the SW180, and the Intes 715 that you mentioned in your last post Wavy. I ask because if the price difference is huge, which I think it might
be, can the extra cost of the most expensive ones be justified other than if
one is either wealthy, or a perfectionist. Incidentally, I had an SW150 some
years ago that had barely perceptible image shift, and did the most
beautiful split of Antares.
raymo

[mental4astro]

Ah, the Intes is not new...

The difference comes down to mass production instruments and the lottery it is to getting what you expect (when you KNOW what to expect), and not having a clue and being happy with what you get. And then the small batch instruments that you purchase only when you know what you are getting, or if it is a status symbol. If you go down the small batch route, you may prefer to buy second hand, and it has nothing to do with wealth.

My own journey in this comes from having had a gutful of poor SCTs, and not getting the detail from the Moon that should be and is "promised" by the SCT producers. Having come to find out that optical quality varies so much, I decided to find a decent scope, now that I know what to expect. Now, if the SCT I purchased was one of the two units that showed themselves to be outstanding instead of the units I did end up with, then I would never have gone on this journey...

If I didn't have my initial prejudice towards Maks, and purchased a 180Mak instead of an SCT years ago, then most likely I would never have gone down this rabbit hole either!

There are also some small batch SCTs made in Japan and Italy, and these are the Ducks Nuts, showing just how good an SCT can be, but they are not in the same price band as mass production instruments.

Like I said in my previous post, the company that is making the Maksutov optics for Synta is getting their stuff really, REALLY good. Heck, I would have loved to have had Wavy's last 180 Skywatcher, but it belongs to Ivan now... Lucky sod.

There is one problem: There are no big aperture Maks coming out of Russia any more. The largest Maks now being made is the 180 from Skywatcher - mighty fine instrument too. This lack of big new Maks will not make the second hand price too kind.

Please remember, there are some fine mass production SCTs out there. If you are happy with yours, then keep it! It will keep performing well for you for a long time to come.

[LewisM]

Alex, I agree with you 100%. Every Intes I have used has been essentially perfect.

I used Matt's former TEC Mak - it was absolutely perfect, and ZERO shift as far as I could tell. It had a Mitutoyo micrometer focuser!!!!!

I have used Mewlons, and honestly disliked them all. Sorry, my opinion. I just don't gel with them, even being a Takahashi nut.

I have used a Tak CN212, and am restoring one for Le Froggy right now, and they are SUPERB - plus you can convert from Cassegrain to Newtonian, making them rather unique. The optics on those are every bit as good as the Intes.

Все русское вызывает увлекательность и исключительность :)

[Wavytone]

Hi Raymo, So... these premium maks 7" and up are quite rare beasties. My Santel is certainly the only one in Australia, and I'd guess likewise Kunama's 8" TEC. After much hunting Alex located an Intes 715D and we know there is also an Intes 815 somewhere in Australia, last known in Victoria.

But if you want one, the real issue is what's currently available new vs secondhand, and you will have a very long wait now for a secondhand one. As Alex said, with Intes closing production the only maks in current production larger than 6" are:

- Skywatcher 180mm
- Orion UK, and
- Questar 7.

If you want to take a look at what comparable maks cost when new, take a look at:

1. APM - back in 2016, the Intes 715D was 3,990 euros, 814D was 5,500 euros, while a 10" would set you back 10,000 - 12,000 euros depending on exact specs. Largest they had was a 40cm (16").

2. Company Seven website (Questar). A Q7 astro version with the fork mount, pier/tripod and a set of Brandons comes in at $US23,000.

3. Orion Optics UK - 20cm f/20 OMC200 is 6,416 UK pounds.

Compared to these the Skywatcher 180mm mak is an absolute bargain and several recent examples I've seen have all been very good, with the last one I owned being very near perfect.

Others: There were also a few large ones made by TEC and AP, but these are out of production and good luck trying to find one.

As for the Santel... I never dreamt I'd own one of these. I knew of three owners online ... until one day Randy Payne decided to sell his, which had been in an observatory and in mint condition. You can still find the list price at http://www.stellaroptical.com/santel-mk9.htm. What I paid stays between me and Randy. Santel made only 28 MK91 and I expect the production quantities for Intes, TEC and AP are likewise small - few will pay the new prices (new).

Lastly, there is also Ottiche Zen in Venice who made some maks 8" - 10" over the years, but now only make optic sets - not finished OTA's - and their correctors are not AR coated.

Are they worth it ? That's up to you, and what you use it for. I've seen people spend as much and more on triplet 130mm refractors, which are no match. As for SCT's... what is evident from side-by-side tests is that the optical quality of Alex's 715D and the Santel are far better than comparable SCTs. I have yet to see an SCT - of any size - give better resolution than the Santel.

[raymo]

Thanks for the comprehensive reply Wavy.
raymo

[mental4astro]

Thought I'd update the current state of large aperture Maksutov scopes.

Russian scopes are not being fabricated for commercial/amateur purchase. These are only available second hand.

The Intes 815 that Wavy mentioned earlier is now in New Zealand.

There is one manufacturer left that produces large aperture Maksutov optics, Ottiche Zen (http://lnx.costruzioniottichezen.com/joomla/index.php?option=com_content&view=section&id=5&Itemid=28), but this is the optics only, not the completed OTA, from 145mm through to 300mm aperture. Ottiche produces some really outstanding quality optics too. Ottiche's Maks are all Gregorian Maks, that is the design that has the silvered spot on the corrector plate like the Skywatcher Maks have. Ottiche also manufactures Schmidt Cassegrain optics.

Astro Physics is making some large aperture Maks, but these are only to fulfill orders made years ago! No new orders are being accepted, so the only way to get you hands on one of these is to buy one from someone who's got sick of waiting for their's.

~x.X.x~

If you have a 7" Mak or larger in diameter, please still let me know. There are a few of the Meade Maks out there, but damn they are hard to track down now. To date, I have not seen one, nor heard of someone who has one or knows of one. These are harder to track down than an Intes or Questar 7! :lol:

Alex.

[Wavytone]

Alex,

At present the only viable sources for 7" and up are secondhand ones from AM or CN and a couple of other websites (as you know), ie Intes, Meade or the rarer Santels.

There are several reasons. Those who have a quality mak in good condition and appreciate what they have are keeping them, pure and simple. If a large one comes up for sale (which is rare) it sells, and quickly. There are a few oddballs, as you know, either in very poor condition needing a rebuild, some of dubious quality (Orion UK), or one-offs made by amateurs.

But new ones... The largest commericial optical glass blanks suitable for Maksutov correctors are those from Schott - and they are a backorder - the size being 200 x 200 x 180 - sufficient to cut correctors for Synta (Skywatcher/Celestron) for the 180mm Maksutovs and 190mm Mak-newts. And these take a staggering 65 weeks from start to finish of annealing - before being sliced, ground and polished.

For the maks larger than 180mm... thats a different game due to the sheer cost of the blank and the time to make it - they are special orders and the price goes up astronomically.

Intes and APM ceased production (mine was the last one).

AP is only making one model - a 10" - and that requires larger blanks to be made as a special order - and their production rate is like 2 per year and the wait list is 20+ years. By all means get in the queue, but many will not be around to receive their scope.

Making these correctors is a mammoth effort - ⅔ of the glass is ground away by the time a corrector is made, and the big Maksutov soup bowls are very, very rare works of fine craftsmanship by the time they are finished. In this respect if an optician has a big glass blank, there is a strong obligation to make it the very best they possibly can. To do otherwise would be disrespectful of the effort expended to make an already very rare blank of the sufficient quality. This is why, when a set of blanks for a 24" surfaced recently in the US, a lot of people went out of their way to save those massive pieces of glass from the tip, despite the probable cost of finishing the optics being north of $75kUS.

There is an interesting account from a fellow on CN making one and he's been at it for 3 years - and the corrector isn't finished.

Yes I can hear the big dob people screaming in the background that they built a 40" for less, but that isn't the point.

[Outcast]

I know where a certain SANTEL & Intes Micro 715D are... but, you already know that... :rofl:

I also know where there is a very, very good Meade 8" SCT LX90 that's for sale but, apparently no-one is interested at present... (no, not you Alex...):D

[Wavytone]

Carlton, I think these scopes were under-appreciated for a long time.

What sparked my interest originally were the lunar images at the Astronominsk website which shows these were in a whole different league to SCTs and subsequently getting in touch with Randy Payne - the original owner of the Santel Alex now has - and realising this was something special, optically. When Randy decided to sell I was aware it was a unique opportunity, as the scope had been in an observatory in a desert in Utah and in near mint condition after 15 years. There were just 28 MK91 made, and I located 4 of them. One of those has been sold in the UK in the past 5 years.

Another MK91 was apparently dropped and the remains (corrector and primary) sold on CN as a fixer-upper, as Alex knows; the buyer (who has a machine shop) is having a new secondary made by Lockwood and attempting to rebuild a new OTA from the Santel drawings. A real labour of love and I hope he ends up with a nice scope out of it.

As for the rest... vanished.

Your M715D is a baby brother, treasure what you have, that is a very fine scope.

Over the past few years I’ve located three other big intes maks - one 8” in the UK, one in US, and a 10” intes (!) in the US.

APM sold the last 11” in mid 2019; a 16” APM/Intes is owned by a CN member plus the 16” Markus Ludes has.

And APM has a 20” for sale, in case you have won Lotto; that is probably the third largest mak ever built.

[Outcast]

Thanks Nick, I certainly will treasure it.. I know that I was extremely fortunate to acquire it through a sequence of events that none of us anticipated...

Unfortunately, since it arrived in the week prior to my fusion surgery I only had one very, very patchy opportunity to catch a glimpse of a few objects. Subsequently, my surgery has put my three favourite hobbies completely off the list of things I'm allowed to do for a few months so, I have not as yet had the opportunity to appreciate just how good it is.... I am looking forward immensely to Feb/Mar next year when my surgeon my let me actually do something other than sit & recuperate & I can finally start to use the Intes for the main purpose I acquired it for, planetary & lunar observing... I'm salivating at the prospect actually......

Cheers

Carlton

[mental4astro]

Oh, and there is one other under-the-radar Mak Cass out there - the Saxon 8" Mak!

There are not many of these out there, but these have been a real sleeper that was unfortunately a victim of essentially being ahead of its time when very few people understood what a Maksutov was and SCT's were all that was known and trusted. A real shame as these really were a very good instrument that can be user collimated, unlike the Meade 7".

Sadly too, these are no longer in production - haven't been for a number of years too. A damn fine scope.

[raymo]

Being as they were badged Saxon, who actually made them, Synta?
raymo

[mental4astro]

No, not Synta. The scopes were made in China, yes, but not by Synta. The firm that made these scopes no longer makes them, probably because at the time there was no demand for these scopes back then. A real shame as today this would be a different story. Especially as manufacturing techniques and quality has been improving over the years with this side of optical manufacturing.

[Wavytone]

The Saxon 203mm mak is curious. I first saw one in the window of Astro Optics back in the days when the shop was in Clarke St Crows Nest, mid to late '80s maybe; and at the time I was fairly sceptical regarding products from a totally unknown brand.

Optical production in China is complex.

In Yunnan province around Kunming there are numerous optical factories which originated in the 1950's from the Chinese military production needs, with commercial products being a sideline. These make batches of equipment to engineering specifications, minimum quantities typically start at 1,000 units. Their main output is boring stuff like the lenses for mobile phones (in tens of thousands of units), cheap camera lenses, the junk in K-Mart, loupes, school microscopes, magnifying glasses to binoculars, and occasionally it extends to eyepieces and small telescopes.

Then there are the "re-badging" companies - Saxon is one, Bosma another. Even Vixen and Celestron. In essence they buy the products in bulk (thousands) from whichever factory was contracted, finish the complete assemblies (eg fit finders, clamps, focusers and throw in an eyepiece or two) slap their label on it and put it in a box with their name on the outside. They then on-sell these wholesale into "channels" that eventually reach the international agents, retailers and eventually sold to the public.

IMHO some company contracted a quantity of these scopes to be manufactured and traded these to the branding outfits - Saxon is one, and later Bosma was another that probably picked up the end of the production run.

Several years ago the Bosma Chinese website briefly featured a 203mm mak "system" with an OTA identical to the Saxon one right down to the unusual ribbed clamp around the OTA - it was both cosmetically and optically identical - except it was all white, complete with finder, a mount (looked like a GP knockoff), eyepieces, various adapters and so-on. It subsequently vanished from their website.

Unlke the Japanese factories, the Chinese didn't adopt the practice of applying a discrete "makers mark" to identify the real origin. Even their telescopes don't have serial numbers. So basically there really is no way of knowing which factory a product really came from, nor the date of manufacture. I'm certain some things were sitting in storage for decades till they were eventually sold.

[raymo]

Thanks for the info chaps. [I'm a pom].
raymo

[mental4astro]

I'm not giving up yet on finding some of these Maks! Not necessarily to buy it, just if only to know what is out there and hopefully get a look through it! :astron:

So, if you have a 7" or larger Mak from Meade or Questar, Intes, Santel, TEC, Orion UK, or whomever, or know of someone with one of these scopes, I would love to know:) Or you may even have just heard something on the grapevine, and even this would be a good lead.

The 8" Intes that was known to be in Victoria I've come to find out is now in New Zealand. I know of just one 8" Saxon Mak in Western Australia that's in regular use. I've also come to know of one Questar 7 towards Richmond in Sydney's northwest, in unknown condition as its been in storage for more than 15 years.

Alex.

[mental4astro]

I can now add a second Saxon 8" Mak, in South Australia :)

Any other 8" and larger Maks out there?

[mental4astro]

Hi all,

Thought I'd post a pic of the "Kremlin of Maks" that happened at my place a couple of weeks ago.

6 Maks, all using Russian made Intes glass.

Left to right:
* Two 6" Maks side by side, an MK67D & M615, on a Losmandy AZ8
* APM 10" with MK66D side by side on an AZ-EQ6
* A 9" Santel MK91 on a modified single arm CPC mount
* An Alter MK1008D, a 10" on an NEQ6 Pro.

We happened to chance upon a night of very good seeing too, so we were able to get each scope squealing with tight collimation. We managed to get the best view of Mars any of us had ever had. Comparing the scopes, there was really bugger all between them to separate them, that is comparing the 6" between them and then the larger Maks to each other. Five of the six scopes were of 1/8 wave or better rated (the "Deluxe" quality issued by Intes), with one 6" being of the standard 1/6 wave for Intes glass.

A night with exceptional glass, going over each with a fine tooth comb, and coming away very impressed with the whole lot.

Alex.

[Hemi]

Gents, maybe not a purists scope, but do any of you have an opinion of the ioptron 150 RuMak? I’ve been seriously considering it but not much out there about it that I could reliably find.

The current SW 150 in the classifieds is also tempting.

....it would be my first foray into Maks.

Cheers

Hemi

[mental4astro]

Hemi,

A Rumak Maksutov has a secondary that is separate from the corrector plate and has its own collimation screws. If the secondary is a silvered spot on tbe corrector it is not a Rumak but a Gregorian Maksutov, just like the Skywatcher maks, and the secondary is not individually collimateable.

The advantage the Rumak has over the Gregorian is the separate secondary offers the scope maker great flexibility in the design parameters and correction of the primary too.

[Hemi]

Thanks Alex,

They have certainly advertised it as a RuMak, hence my interest. In fact sidereal trading have as well. I read the manual after your post, and you’re correct in that collimating is via the rear cell only, no mention of the secondary.

It is puzzling though as it clearly states a RuMak type secondary mirror, not a silvered spot on the corrector as in Gregorians.

Cheers

Hemi

[GUS.K]

I remember a thread on CN regarding the ioptron Maks, they had an issue regarding the secondary mirror sliding out of position they are apparently glued on.

[Buck]

These iOptrons are definitely a Rumak design. They were reviewed by Dennis di Cicco in the Nov 2011 Aust Sky & Telescope, and to quote the reviewer "The scope is a Rumak design, meaning that the secondary mirror is a separate optical element glued to the inside of the strongly curved Maksutov corrector ...."
They have three sets of collimation push-pull screws sealed under dust plugs at the rear of the primary mirror and come with a dual speed focuser that has an internal pre-load that prevents any "mirror shift" that can occur with the SW versions.
They are very rugged - I accidently dropped mine (onto soft lawn) and there was no damage or change in collimation.
Haven't heard of or experienced any secondary mirror "slippage". They do get a good report/review in Aust S&T and also in Astronomy Now back in 2010.
Under-rated in my opinion......
Buck (Paul)

[Hemi]

Thanks Buck, for the clarification. My reading had certainly pointed me to that conclusion...

As I said earlier, I’m very tempted.

Hemi

[Steve Pattie]

I have had in storage for a few decades now a Mak (just under 7.5") made by the Australian optician Bill James of Melbourne. As far as I know it is a one of a kind.

[mental4astro]

OMG! A rogue Unicorn!

Steve, WOW! That's all I can say!

Do you have any other specs about it, such as focal length? What size focuser does it have, 1.25", 2"? How much does it weigh? Any coatings on the optics?

I haven't heard of Bill James. Any details you can share about the man? Not his phone number... , but his work.

Any chance of a few more pics? Down the OTA, the rear, mounting plate, etc, would all be great to have a squizz at!

And of course, how does it perform???

Damn I'd love to get a look through it! :D But it's too far away... :sadeyes:

Alex.

[Saturnine]

That is an interesting scope to come out of the closet, after being in storage for so long is there any thought of putting the scope on the market. An Aussie made Mak , like Mental, I would love to know the specs on the scope and any test results.

[Stefan Buda]

Back in the early 90s I purchased what I believe to be the last two 8" borosilicate meniscus blanks from the batch that was used by Bill James to produce this scope. I have turned one of the blanks into a 7.5" Gregory (not Gregorian as there is no such thing) Mak, in the mid 90s. That scope is somewhere in Europe these days, but I still have the second meniscus blank and would be very happy to part with it if someone wants to swap it for a 10" Pyrex blank.
Bill James was the most prominent optician in Australia until his death in 1995. He is mostly known for making the large Wynne corrector for the AAT and the laser reflectors for the Optus B satelites.

[Saturnine]

Stephan

Thanks for the background info on the Bill James Mak, sounds like it should be a good performer , going by the opticians credentials you mention.

Steve Pattie
Please tell us more about the scope and how it performed on the planets etc.

[Steve Pattie]

Hi Alex,

The Mak is for memory f/15 and comes with an older style 1 1/4" focuser. There are no coatings on the optics and its weight is 7kg.
Stefan gave some stats for Bill James, Australia's best optician who emigrated to Australia from the UK with his young family. He had a workshop in Camberwell and he has made up to a 40" mirror for someone in Tasmania (my memory is a little hazy on that one) - it was still on his work table when I visited him. He also remade the optics of the Govt 8" refractor at the Old Melbourne Observatory making exact test plates of the original glass to reproduce the exact figures they had even though he said that the design wasn't optimal. On my last visit there, he showed me the Mak and gave me a price for it, which I snapped at - $1000 some 20+ years ago.
Unfortunately due to the tube design, I didn't have a mount to put the thing on and still don't, so I have never looked through it in all this time.
I'll take some snaps of it over the next few days to show you.

[Saturnine]

I am looking forward to seeing more photos of the Mak and possibly more dimensions of the tube if it is not too much to ask.

[blindman]

One near you

[mental4astro]

It would certainly be very interesting to compare the Bill James made 7.5" Mak with a current Skywatcher made 7". Of course there will be difference due to the lack of anti-reflection coatings on the 7.5", and the image will be a little dimmer because of the age of the scope, but the relative optical quality of each instrument will most certainly be on show.

[Steve Pattie]

Here are some more pics of the Mak Bill James made. It appears that the focuser has either been modified of custom built.
The overall length of the optical tube is 494mm and the OD of the front cell is 213mm.

[mental4astro]

Thanks for the pics and specs, Steve.

I'd jump at the chance to have a look through it. Looks a treat for sure.

Alex.

[Steve Pattie]

Heh Alex, that may one day be possible. Let me work on something first.