Review of the 20” f/3.4 Reginato Supermaser

I am the lucky owner of a 20” f/3.4 Reginato Supermaser. The Supermaser is a telescope based on the dobsonian, but in a different league when compared to traditional ones. Instead of wood it uses metal, which allows the user to have a very stable instrument with an almost total absence of vibrations. The optical and mechanical quality are at the highest levels and not mediocre like many mass produced telescopes. After about one year and a half of use, I would like to share my experience so far with this mechanical jewel here on CN.

Introduction

I am an amateur astronomer based in Aosta Valley, a little region in the Italian Alps (by the way: sorry for my bad English). Despite the young age, I have about twenty years of experience with telescopes and I had and tested many of them. I started with the classic Newton 114/1000 mounted on a horrible EQ1, and after many years I made the upgrade to more sophisticated instruments, in particular two C9.25 Edge HD (one on an alt-azimuth CPC Deluxe mount and the other coupled with a 10Micron GM2000HPS II mount). Thanks to my beloved 10Micron mount I became fully aware of the limits of commercial Schmidt-Cassegrains and I learnt that mechanical quality is at least as important as optical quality. I then bought a 5” TOA refractor, a terrific instrument, both optically and mechanically, visually and photographically. Its only “problem” is, in fact, the modest diameter. Little by little, aperture fever started to grow.

A couple of years ago I finally had the opportunity to buy my final telescope. I was looking for an instrument with the following specifications:

• the telescope had to be easily transportable and quick to assemble/disassemble
• the mechanical quality had to be excellent, as previous telescopes taught me
• the optical quality had to be excellent (I really like to observe planets in addition to deep sky)
• the telescope had to be able to cool down in a reasonable time (1 hour max)

These criteria narrowed a lot the possible choices, given that none of the commercial telescopes satisfied all of them simultaneously. After a lot of research, I selected two possible instruments: the Northek Rapido 450, an 18” f/4 very mechanically advanced telescope, and the 20” Supermaser.

The Northek initially seemed the perfect solution: it is a f/4 telescope (I was concerned about the very fast f/3.4 Supermaser, because I thought that the optical quality was necessarily compromised with such a fast mirror). In my head, an f/4 telescope was the guarantee of a better optical performance. At the same time, however, the Rapido 450 is extremely heavy and has a way too large basement, that seriously limits its mobility.

I decided to contact Silvano Reginato (the first of many many phone calls: Silvano has always been there, ready to clarify any doubt or question I had, with great patience and kindness), and expose the situation and my doubts. After more than an hour of phone call, two things were clear to me: 1) Silvano knew its job and 2) I wanted a 20” Supermaser.

It was certainly a good choice: the telescope combines excellent optical and mechanical quality, every single detail is carefully engineered and nothing is left to chance. Is it a perfect telescope? Probably not, but it is truly excellent, with an unreachable quality for all the mass produced telescopes (and probably also the vast majority of premium dobsonians). The waiting time has been slightly longer than expected (instead of 7-8 months I had to wait 10 months in order to receive the telescope, because of the COVID pandemic and the consequent scarcity of the raw materials in Europe, particularly aluminum), but it was worth it. Throughout that time the communication was excellent. During all the process Silvano was ready to adapt - as far as possible - the telescope to my needs, he was really kind. 

The after sales experience was equally satisfying: for example, Reginato sent me for free additional counterweights because, with my quite heavy accessories, the telescope wasn’t properly balanced. He also replaced for free the counterweight wooden case with a larger one (yes, the telescopes comes with three high quality wooden cases; one for the truss tubes, the second for the upper ring/finder/Argonavis etc and the third for the counterweights - the other cases are optional).

Below I’ll try to show the characteristics of the instrument with the maximum objectivity possible. For those who already are desperate to read a treaty, in the conclusion I list the main advantages, disadvantages and things to consider for those who are potentially interested in the purchase of a Supermaser.

My instrument

As anticipated, I bought the 20” version. After talking many hours with Silvano Reginato, I opted for some improvements over the basic version:

• first of all, I wanted the best optics possible (the standard Supermaser is sold with 1/4 lambda mirrors).  Optical quality, as already mentioned above, is an indispensable requirement for me, since I really like planetary observation.
• in order to have the maximum rigidity, I asked for carbon fiber truss poles, which replace the standard aluminum ones covered with rubber for a safer grip.
• I wanted an instrument quickly usable, so I added the fans, as well as the wheels and dumbbells, that let me move the telescope entirely assembled from the garage to the garden, where I do 80% of my observations, in a couple of minutes.
• since I really like to show the wonders of the universe to my friends and other people, and because of the added comfort, I opted for the version with Argonavis. This way, the pointing routine becomes a matter of seconds. In order to have a better pointing precision, I also bought a spirit level and the adjustable feet.
• finally, I opted for the integral upper lens hood, in order to better shield the light pollution of my town.

During these 17 months, I also added the 80 mm finder and I bought the case for the lower part of the optical tube, necessary if you want to safely transport the telescope fully disassembled.

Aesthetics

In my opinion its a marginal aspect, so I’ll only write a couple of things. The paint used by Reginato seems to be very resistant. My Supermaser has a minimal aesthetic defect, because on one of the truss poles there are traces of the glue used during the construction of the telescope. It is completely irrelevant and almost invisible, but the glue is definitely there.

This little detail apart, the telescope is simply magnificent.

Assembly/disassembly of the instrument

Assembling and disassembling the Supermaser is a matter of minutes. There are many details that make the operation easier and without risks for both the user and the telescope. I start by inserting the fork on the base triangle and tightening four levers. In the fork there are four supports for the breech of the telescope. At the top of the fork there are the housings for the central ring (the telescope has a double truss, which makes it more rigid and better performing: a truss connects the breech and the central ring, the other one the central ring and the top ring). The truss poles are built with extremely little tolerances and are therefore exchangeable without any consequence: the collimation is not affected. The operation is extremely quick thanks to proprietary joints. At this point, in order to attach the upper truss and the top ring with comfort and ease, there is the possibility to block both azimuth and altitude movements. The telescope thus is still, with the tube almost parallel to the ground, and the upper part can be easily and quickly mounted. The counterweights with their bars must then be inserted on the back of the breech. In the top ring there are brackets for the handle, which allows you to guide more easily, making very fine movements, a red dot finder/laser pointer and the finder. The assembling requires less than 10 minutes. If desired, the light shields can also be added or removed whenever you want without disassembling the telescope, and kept in the right position thanks to a really smart proprietary system.

Everything is really well thought. You can also add a third shield, which is inserted above the top ring with eight rods that keep it in place. Initially I was uncertain about this system: it seemed to me that it was unnecessarily cumbersome. After using it a few times, however, I discovered that it is functional and extremely easy to store after the use, compared to rigid shields such as the Astrozaps for Schmidt-Cassegrains. 

Picture 1: one of the many details that make life easier to the user: the light shield can be added or removed easily in a second moment thanks to Velcro straps, without the need to disassemble the upper ring and/or all the accessories.

Picture 2: the optional third light shield is not rigid like Astrozap and similar solutions. It can be easily stored. In the right image you can see the eight rods ready for the light shield.

Transporting the scope

The telescope can be entirely disassembled and therefore is relatively compact in relation to its generous diameter. However, a car with a big trunk is required, especially if you want to transport the lower half already assembled and thus to save further time when reassembling the telescope. In this case there are two possibilities:

1. if you use the (optional) wheels you can load the telescope in the trunk with a ramp. However, it must be considered that the wheels protrude from the fork, adding depth to the telescope. The car trunk must be long enough to accommodate base+wheels.
2. With the help of a second person it’s possible to lift the lower half of the telescope without any problems (it’s surprisingly light).

The alternative, if you do not find yourself in one of those two situations, is to fully disassemble the telescope. However, I would recommend, in this case, to buy at least the breech case, so the primary mirror travels safely.

Thanks to the optional wheels and dumbbells, the telescope can also be moved by hand completely assembled, if you have a good observing location near home. This is what I do 80% of the time, and it is extremely quick and comfortable. This way the telescope is virtually operational in two minutes, the time to transport it, remove the caps and check the collimation. The only drawback is the fact that the wheels are quite close to each other: if they were slightly more spaced the telescope during transport would be even more stable. In reality, however, I didn’t have any real issues, even when moving the telescope in the garden, on an uneven ground, so I cannot consider it a defect.

To be honest, when moving by hand the telescope I had an issue with the feet. They can easily bump the ground and the lower part tends to fall off - it happens more or less half of the time. After moving the telescope, therefore, it is a good practice to verify that the feet are still in place. It’s quite annoying, but they are really easy to reattach to the base.

Picture 3: The Supermaser fully assembled with the optional wheels and dumbbells.

Acclimatation

The 20” model has a mirror with a thickness of only 39 mm. The mirror is therefore quite thin (always in relation to the diameter, of course) and cools down quite quickly: no miracles here, but even during winter after more or less one hour the telescope is ready for satisfying high magnification DSO observations. It is definitely another world when compared to 9.25” or bigger diameter Schmidt-Cassegrains, which have big thermal problems in my experience and are never really acclimated. During these 17 months I had to use the fans twice, if I remember it correctly. 

High magnification planetary observations are a little bit more difficult. Actually, the biggest problem is not acclimation, but the seeing, that where I live is rarely good enough for such a big diameter.  

Stability/vibrations

The Reginato website says that "Thanks to the special altazimuth steel frame combined with a crossed double-truss optical tube (Serrurier type) entirely in aluminium alloy, SUPERMASER telescopes are almost free of vibrations during focusing, even at high magnifications". Fortunately, it's not marketing, it's real. I tested that by hitting the top ring with the hand and there is a dampening time of about a second, a very good value (while not comparable to a really rocky mount like the GM2000). When focusing I never had any problem, there is no sign of vibrations: the mechanical quality of the telescope is really good.

Even with wind gusts the vibrations are almost absent (but I never tried in the middle of a tornado, perhaps in that case there would be problems). In this situation there is another problem, the sail effect, especially when light shields are used. In this particular situation, guiding at high magnifications can become complicated because the wind tends to move away the optical tube.

Collimation

The telescope maintains collimation very well during all the night (in fact when I don’t disassemble it collimation is perfectly maintained for weeks and months). After car travels with the telescope half assembled, it is usually necessary to retouch it slightly (really slightly). For testing purposes I disassembled and reassembled the upper part of the telescope a few times while at home (without carrying it in the car, with all the consequent vibrations) and the collimation is perfectly maintained. It is really impressive. Even with the telescope pointed almost parallel to the ground there are no significant flexions, with an important caveat.

It seems that the focuser (a Feather Touch) has some play and therefore a minimal flexure. I am not able to evaluate the possible impact on image quality, but it certainly isn’t a serious issue (after all, the Feather Touch focusers, while not perfect, are certainly not garbage…).

Even when fully disassembling and reassembling the telescope collimation, while absolutely non perfect, isn’t horrible. In a couple of minutes, with a laser collimator I’m able to perfectly collimate the telescope.

Operating the telescope: pointing, guiding, Argonavis

Like any Dobsonian, the Supermaser was originally conceived as a completely manual telescope. However, it is possible to install Argonavis (possibly also Nexus, I don’t remember) and encoders, for an even more comfortable pointing experience.

I opted for the latter solution because of two reasons: 1) since I like to observe with friends, I need a telescope that if necessary can be pointed quickly, in order to reduce dead time. 2) Undoubtedly the Argonavis allows me to speed up the pointing operations, a really good thing when I don’t have a lot of time for my observations.

Personally, I find the Argonavis menu a little too crowded and not very intuitive. Once the two or three important submenus are mastered, however, the experience is positive. The alignment is extremely rapid, but a couple of times the pointing precision was not excellent. In this case it is perhaps a good idea to also use the finder for the final centering. Most of the time, however, the experience is flawless, so much so that the objects are in the field of view of my Ethos eyepieces also at 250x. There are two further considerations to be made:

1. The Argonavis can also be used without power cables (it also works with batteries), but it does not give informations about the charge level. It already stopped to work in the middle of an evening with my friends and I had to point the telescope manually. It is always better to make sure that the batteries are charged and/or bring replacement batteries.
2. The pins of the encoders and the cables seem very fragile. It already happened to me, I don't know how, to bend the pins of the azimuth encoder.  Probably they will be the first part (and the only one, if there are no strange accidents) to break.

When the Argonavis, for one reason or another, fails, the user can still manually operate the telescope. I initially opted for the standard 50 mm finder with an illuminated reticle eyepiece. Unfortunately, the eyepiece was broken, but I replaced it with another that I already had while waiting for the replacement. Unluckily (but it’s a subjective thing) the 50 mm finder is uncomfortable to use if you are not two meters tall/you do not use a ladder/you do not lower it some way. For this reason, and because I wanted to see the objects in the finder more easily, after almost five months I purchased the 80 mm finder, which is long enough to be really comfortable to use even when pointing the Supermaser at the zenith. The eyepiece the finder arrived with (a Svbony 70° FOV, 20 mm illuminated eyepiece) is not perfect (there is a very evident coma from the middle of the field onwards), but I replaced it with a 14 mm Delos and I am extremely happy with the performance (of course, the field of view is not very big - more or less 3°): a red dot finder or a laser pointer are in my opinion the perfect complement for such a beast.

At this point I think that a small digression is necessary, since surely many amateur astronomers have already found themselves in the same situation. As anticipated in the introduction, I started my experience with a classic 114/1000 Sky-Watcher newtonian on a really cheap EQ1 equatorial mount. The telescope, super-economic, was not easy to use: the finder was really difficult to align and was practically unusable, given the small size and the poor magnification, the mount had severe play and wasn’t very stable... logically, after that telescope, I decided to buy computerized mounts, much less frustrating to use. When thinking about buying a manual telescope I was hesitant because of this not very positive experience (which is why I took the Argonavis, in addition to the reasons explained above), but after many months of field experience I can say that my fears were completely unfounded: with a good finder, manual pointing becomes a joy (even if sometimes long). In addition, the Supermaser mount is really fluid in movements, so much so that it allows the user to guide even at very high magnifications (if I remember it correctly, I also used it with a 530 magnifications eyepiece without any problem). With an adequate telescope, manual operations are a really satisfying, rather than frustrating, experience.

Even beginners, especially with the Argonavis equipped version, are perfectly able to track at medium magnifications (250x), as I have experienced with my friends: after a couple of minutes they were perfectly at ease with that. The vast majority of them was using a telescope for the first time. 

Optical quality

The deep sky is, of course, where the instrument excels. I have not done scientific tests, but I am very sensitive to all kinds of aberrations and apart from a minimum of coma visible at the extreme edges of the 21 mm Ethos (with the other eyepieces the image is perfect, when seeing is good. Evidently the Paracorr is not able to completely correct the coma of the Supermaser with the 21 mm Ethos - and only with that eyepiece) I have never found anything relevant. The contrast is very good, even under a less than optimal sky like the one I have at home, a sign that the surface of the mirrors has a low roughness.

The telescope, when used in the field, displayed an excellent quality. At equal magnifications, stars were just a little bit larger than those showed by the Takahashi, though it does not reach that absolute purity. On the other side, in my experience the Supermaser is way better than commercial Schmidt-Cassegrains. I performed many times, with different seeing conditions, a star test using Suiter’s manual as a reference. The global correction (taking into account both the mirrors, the Paracorr and Ethos eyepieces) is about 1/6 lambda P/V, a very good value for such a fast telescope and so many optical surfaces.

I also pointed the telescope at Jupiter, Saturn, the Moon and Mars, with good results. On Jupiter and Saturn in particular I conducted a test, in a night with 3/5 seeing, with the Takahashi on the 10Micron next to the Supermaser, so as to have a reference. On Jupiter, which is very high in the sky this year, the Supermaser was able to show more details the rare moments when the turbulence decreased as well as, of course, a much brighter disk and much more saturated colors. On Saturn, which at that time was about 25 degrees above the horizon, the situation was different: the Takahashi, much less sensitive to turbulence, showed sharper and more enjoyable images. Another night I repeated the test, this time on the Moon. As with Jupiter, when the turbulence decreased the Supermaser undoubtedly showed finer details. On Mars, which at the time of observation had a diameter of about 12", Vallis Marineris was evident as well as the phase (it was 88% illuminated). That night, unfortunately, I didn’t have the Takahashi alongside.

I live in a not so good place seeing-wise, so I ended up using most of the time a mask with 18 cm of clear aperture (much more usable than 50 cm!). With that mask the telescope is absolutely terrific, even when the seeing is not perfect. It completely destroys my beloved 5” Takahashi. Of course when the seeing is good enough the full aperture images are really enjoyable.

Practical considerations based on field use

To use this telescope is a joy, but in my opinion there are some aspects that perhaps could be improved or that simply need to be taken into account.

• The upper light shield, if mounted according to the instructions (with the leather-like surface facing outwards), doesn’t completely shield light, because in the upper and lower part there is a 1 mm gap. If you observe in a place far from stray lights you won't have the slightest problem; if instead, as in my case, there are street lamps twenty to thirty meters away, unpleasant reflections in the eyepiece are a real possibility. Fortunately, there is a very easy solution: it’s sufficient to just mount the shield reversed, with the leather-like surface inwards. When doing so, a couple of cm of the shield protrude and can be superimposed on the top ring and the central ring, completely cutting out the stray light (see picture 4: it is easier to see than to explain).
• Harder clutches, especially in altitude, would be welcome. When I change the eyepieces or, even worse, the entire group of Paracorr + eyepiece, the telescope is suddenly heavily out of balance and moves away. It would be nice to be able to make the change without having to point the object again.
• The Argonavis support is a bit shaky. It's not a big problem though.
• The rubber surface of the tracking handle is slightly too large for the handle. It doesn’t risk to fall, but it can slightly move in the hand. Of the whole telescope it is the only detail that seems a little bit less accurate to me.
• Moving on to the aspects that must be taken into account, the telescope is large and tall (big surprise, I know). To give a reference, I am about 180 cm tall and I barely reach the eyepiece when I point the telescope towards the zenith. For many people, it may not be a problem (it’s sufficient to use one or two steps). For those who observe in a place where it is not easy to carry a ladder or those who simply don’t want to take their feet off the ground, this aspect must be adequately taken into account. It is not a telescope that I would recommend if you plan to have educational evenings with children.
• I have already said it before, but it’s useful to repeat it: wind gusts tend to move such a massive telescope. Pointing and/or guiding can become quite difficult at high powers (but nobody uses high magnifications with strong wind, I think).
• If you use heavy accessories, the standard counterweights may be too light. If you plan to use eyepieces such as the Ethos 21 mm + Paracorr + 80 mm finder scope, it is better to get heavier counterweights immediately.

Picture 4: on the left, the light shield mounted the classical way. On the right, the light shield is mounted reversed. That way the stray lights are completely blocked.

Conclusions

It is difficult to find downsides for such a telescope. There are certainly some aspects that can be improved, as I pointed out in the review, but overall it is a jewel. The best proof is that since I have it I used the Takahashi four times: twice to compare it to the Supermaser and twice for observations with friends (one of them broke his leg and couldn’t reach the eyepiece with the Supermaser).

Optically and mechanically the telescope is very good. The only real drawback is the price, but it’s proportionate to the performance of the instrument, which is at the top of its category.

Pros:

• Very good optical quality
• excellent mechanical quality (stability, almost total absence of vibrations, collimation, care for every detail)
• acclimatization speed
• ease of transport (both by car and manually)
• ease and speed of assembly/disassembly
• ease of use in the field (fluidity of movements, quality of the finder…)
• relative lightness
• pre- and post-sales support

Cons:

• a couple of secondary accessories look cheaper, while still working fine

• if you have the version with Argonavis, the encoders and their cables seem fragile

• the clutches are not always sufficient to compensate for the imbalance when changing the eyepieces

• the Feather Touch focuser, although very beautiful, has some minor play

Things to consider:

• height of the eyepiece at the zenith (potentially a problem for people shorter than 1.80 m)
• with very heavy accessories, heavier counterweights are needed
• if you do not have a large car and/or cannot move the telescope partially assembled, the entire set of cases is necessary for safe transport
• sail effect when there is wind (difficult to consider it a cons, it is inevitable)
• price (again, it’s difficult to consider it a defect)

Picture 5: the Supermaser in all its glory, ready for a night of observations.