Skymax 127 SupaTrak pt2

By Antony McEwan

Second and Third Lights

…Which took place at a local dark sky site on a cold December night. I set up exactly as I had before and started observing. The focusing jiggle with the ED80 was slightly improved but not completely eliminated. When I owned the Celestron SLT mount I had attached a TeleVue85 refractor to it in the same way as my current SupaTrak/ED80 combo was set up and the SupaTrak dealt with the weight much better than the SLT did. Now on this second night the tracking was not as good as it had been on the first night. I reinitialised a few times and then resorted, as everybody must occasionally, to reading the instruction manual. It seems that to maximise tracking accuracy and minimise backlash errors it is important to use certain direction keys when setting up rather than others. For example, when levelling the tube and when pointing at Polaris (setting latitude) it is recommended to finish those procedures using the /\ and > buttons. Also, whichever of those keys I use last when levelling the tube before resetting the power, I should then make sure it is also the last one I use before setting the latitude after acquiring Polaris in the ‘scope’s finder. I think I’d missed that. By the time I’d realised this it was too late to do anything about it, so I resolved to try those tips out next time…

The altitude scale makes it easy to set latitude for tracking.

…Which took place a week or so later! I had spent many evenings scouring the instruction manual, trying to remember all these tips and pointers to maximise my enjoyment of this mount. It’s actually quite important to do so, I think. There are tips dotted about all over the book, not in any one specific place, so it’s worth hanging onto the manual when setting up the first few times. Anyway, once set up, the tracking was better – much better than the second light and almost as good as the first light experience. Strangely, it seemed that tracking accuracy was best when the target was higher in the sky. When viewing Mars, for example, at 230x in the Maksutov, it stayed in the field of view quite well, requiring only moderate tweaking every few minutes. But when viewing M42, much lower in the sky, it required more frequent tweaking to keep it in the eyepiece’s field of view. I find this interesting, and am sure that I may have missed some other obscure little tip that may fix this. It does not put me off too much.

When not being used astronomically, the SupaTrak has another feature that may interest birders or other types of daytime observer. It is possible to store up to six locations in the mount’s memory by slewing to the position and then pressing the ‘Set’ button on the hand controller. When the locations are set you can then do a tour of them by initialising the ‘Cruise’ function. The mount will slew to each position in turn and stop there for five seconds before moving on. You can interrupt the tour if you want to stop at one particular place. If left uninterrupted, the process will repeat. You also have the option of selecting any one of the locations, hitting ‘Go’, and the mount will slew directly to that place and stop. An interesting feature that holds no interest for me that I know of yet, but I’m sure someone out there will find it useful.

Conclusion

As far as this mount goes, I consider it to be a very useful piece of equipment. It can hold different styles of telescope tubes, including Maksutovs and Newtonians up to 5” aperture, 80mm Apo’s, 100mm short-tube refractors, etc. It’s quite lightweight overall (5kg without tube assembly) and easily assembled, although as with any mount that tracks, the more carefully it is set up the better the result will be. And it’s cheap: Seriously cheap. My package came with a 127mm Maksutov that normally retails by itself for just under £300 – and I got this with the mount and accessories for just under £300! Talk about a no-brainer! Ok, I added a 1.25” dielectric 99% reflective diagonal by Astro-Tech to the shopping list (£45) as I like my diagonals to be as highly reflective as possible, but even so it’s still a cheap set up. I look forward to making a bracket to hold my Coronado PST and using the mount to track the Sun while I observe.

Now bear in mind, if I want ultra-accurate reliable tracking when observing I will use my Vixen GP equatorial mount with dual drives and wooden tripod. It is far and away the better mount for holding a target in the field of view indefinitely. But for quick looks, travelling, or as a grab’n’go package, the SupaTrak serves very well as a sturdy alt-azimuth mount that just happens to have tracking built-in. That’s the way I look at it anyway.

Maksutov Tube Assembly

As for the Maksutov tube assembly, I am enjoying having one back in my collection of telescopes. The five inches of aperture are contained in a very compact portable tube, making it ideal as a medium aperture grab’n’go telescope. The long focal length of 1540mm means the focal ratio is just over 12, making it ideal for planetary and lunar viewing. Medium and long focal length eyepieces provide relatively high magnifications, which means that eye relief is usually comfortable and image scale (the virtual size of the object under scrutiny) quite large. The field of view is flat, meaning that stars at the edge are focused to the same extent as stars in the centre of the view, and there is a very large range of focuser travel, so virtually any 1.25” eyepiece will come to focus. Note that I have not yet used the eyepieces that came with the ‘scope. I have instead used my trusty TeleVue Plossls, Pentax XLs and Meade Ultra-Wide-Angle. I’m a fervent believer that adding good eyepieces to any telescope can only improve the view.

The focuser will only accept 1.25” diameter eyepieces and there is no official way of converting the visual back to accept 2” diameter accessories. The focus knob is small but quite smooth in operation. Focus is achieved by moving the primary mirror, which can result in some ‘image shift’ when focus direction is changed, but it is really not that bad at all. Views are sharp and bright, and I was able to resolve considerable detail on Mars at 230x. By comparison, the same detail was visible in a 6” f8 Newtonian on the same night, but the Newtonian’s view was slightly brighter. The sky background appeared slightly darker in the Maksutov, which suggested slightly higher contrast, but that may be a function of its slightly smaller aperture. I noted that when used on the SupaTrak mount the focus jiggle that marred my experiences with the ED80 was much better with the 127 Maksutov. The tube is shorter, so I suspect that the length of the telescope tube may have a bearing on that.

The fiddly end.

Build quality is fine, and it feels quite well put together. On close inspection of the interior of the tube, there does appear to be a very small amount of debris (dust and a tiny hair!) inside the tube, but I cannot be sure that it was there when the telescope arrived. It may have found its way inside since I obtained the telescope. How does such debris get inside a sealed optical tube? Answers on a postcard please. It’s not the worst I’ve seen!

The tube does take a while to cool down to ambient temperature. It is required that you allow this to happen or the image in the eyepiece will not settle but will shift and boil due to the tube currents caused by different temperatures inside and outside the tube. I found that an hour was the minimum cool-down period before high power views could be routinely attempted, and the longer it was left to acclimatise the better they got.

It is a very rewarding telescope. Clusters appear very contrasty and sharp, planetary features are sharply defined, and the Moon is literally out of this world! The stark whiteness of the lunar surface explodes out of the eyepiece and the contrasting black shadows of crater depths and rilles appear to be etched or engraved on the view. It is a memorable experience viewing the Moon at high magnification with this telescope. The field of view is slightly limited, as the long focal length means that you’re never going to get a truly wide-field experience with this ‘scope. My Vixen 22mm LVW with an apparent field of view of 68 degrees yielded 70x magnification and a true field of about one-degree, which is perfectly respectable. The telescope split Rigel easily at that magnification, with clear black space between the two components. M42 showed remarkable detail, with a really 3D effect in the clouds of nebulosity. Given that this telescope is replacing a 6” f8 Newtonian in my collection, I do not think that I’ll miss the extra inch of aperture, and the overall quality of the views in this telescope can be described as very pleasing. It really is a joy to use.

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