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I have had my Hyperion Zoom Mk.III for quite a while now and I was wondering, if I should review it here, because what there is to say about an eyepiece, really? You just shove it into your focuser and look down the glass end, right? Well, since the Hyperion Zoom is effectively 5 eyepieces in 1 (I don’t really think it’s that big of a deal), it is not really a “static” piece of equipment, and there is lot of “accessory” for it, I thought I’d give it a try. Optics Optically, the eyepiece is a “seven element eyepiece, with multi-coated optics for remarkable sharpness, contrast and colour correction.” I am in no way an expert in optics, but I have to say that the quality of the image outperforms my pervious eyepieces, primarily in sharpness and contrast. I even had a 12mm Hyperion normal eyepiece for some time, and when compared, the views through the two were pretty much the same. Even in my F/5 dobsonian, the image distortion at the edge of the field of view is really not bad - though there, I do not really notice it that much; it is only when I zoom out to 24mm focal length that the distortions become really noticeable. There is a shaft, sticking out of the body of the eyepiece, in which the movable part of the zoom mechanism moves in and out, and I simply never get tired of the action-packed zoom action. One problem can arise though, and that is that any imperfections on the surface of the lenses inside the eyepiece can get, due to its zoom nature, visible at some point - that way, I once noticed a quite large piece of dirt inside the optics, which came into focus in 12mm position - this was really bothering me, because it was extremely disturbing, especially when observing the Sun or the Moon. Luckily, somehow, the piece of dirt disappeared (after bumping the EP gently on the table), so there is no need for returning it to the supplier. The piece of dirt did not appear again ever since. It is said that normal eyepieces outperform zoom eyepieces, but I am not so sure. Well, on one hand, you get a narrower field of view, that is true, but the quality of the image delivered (with Hyperion Zoom in particular) is really very good and if you are not traditionalist, or fond of ultra-wide fields of view, this age-old paradigm suddenly gets null and void and a concept of having half a dozen eyepieces suddenly gets, well, stupid. Having one decent Zoom eyepiece just seems more practical. Personally, since I have bought my Hyperion Zoom, I have not felt any need of buying a new eyepiece (for the particular range of magnifications), because it embodies everything I do (and will) need at the moment. Furthermore, the edges of the lenses are apparently blackened, and the EP’s construction allows very little or practically no reflections of brighter objects. Accessory The Hyperion Zoom comes with a wide range of “accessory”, if that is the right word; basically you get two different rubber eye cups (I even got a rubber eye shield, but I am not sure if that was part of the package, or a gift from the supplier), and both allow you to use the eyepiece comfortably, even when you are a glasses wearer; the eye relief is generous enough to allow that, though I am sure there are EPs with better eye relief than Hyperion Zoom. Furthermore, you get adapters for both 2” and 1.25” focusers. I personally prefer to use the 2” one with my 300P, because it feels more firm and solid, and the inside of the 2” adapter is “baffled”, which seems nice. One thing that I do not really get is that when you use 2” adapter, you can’t use 1.25” colour filters at the same time. The shaft, in which the movable part of the eyepiece moves in, is of just the right diameter, and it even has a thread on the end of it; but somehow, the boffins at Baader did not think to make it standard 1.25” filter thread, and that is a pity. I think it would be wonderful to have a freedom of filter choice, but that way, you can only use 2” filters with the 2” adapter and 1.25” filters with the 1.25” adapter; too bad. Perhaps, they will address that on Mk.IV. Furthermore, you get a wash of dust covers, just in case you use any of the possible combinations of eye cups and adapters, which means you can easily lose one if you are not careful. The eyepiece also comes with rather elegant leather-ish bag for you to store it in, which I, think is a rather nice touch. Usage The most prominent feature of this Zoom eyepiece is its…well…zoom capability. The eyepiece has click stops at 8, 12, 16, 20 and 24 mm focal lengths, which means that it can deliver a wide range of magnifications, depending on your telescope’s focal length. I for instance have a 305/1500 dobsonian, which means that I get 62x, 75x, 94x, 125x and 187x magnifications, which is a range good enough for most objects up there. It should be said that the EP’s field of view varies with focal length - basically, the shorter the focal length, the wider the field of view; the longer the focal length, the narrower the field of view (it’s actually 68° FOV with 8mm and 50° FOV with 24mm). Of course you can use any focal length between the click-stop position as well. Furthermore, though advertised, the eyepiece is not perfectly parfocal (meaning that it holds focus at all focal lengths), which means you have to refocus every time you change the EP’s focal length. I know that there are eyepieces with better FOV that are perfectly parfocal, but these can get way more expensive than the Hyperion Zoom. It is fair to say that I have heard that some people find their zoomy Hyperions stuck when it’s freezing out there, and thus the eyepiece needs regreasing. However, I have used mine in temperature below -7°C all night, and although the zoom action felt more stiff, it did not get stuck even a bit, so if there really is a problem with it freezing solid, I reckon it is an effect prominent overtime. However, the Hyperion Zoom is not that cheap - it costs roughly the same as two fixed focal length Hyperion eyepieces, which is quite a lot, but then, you get a variety of magnifying power in one eyepiece, and it is just great not having to change the eyepieces all the time, every time you want to try different power. One of the best things on this eyepiece comes with it zoom capability - without having to change the eyepieces, you can toy around with magnifications to see which magnification delivers the best contrast on the object you are looking at - this is due to the fact that the contrast of the background often changes with magnification (e.g. when you zoom in, the background gets darker), which means that some dim objects can miraculously pop up, or seem more distinct. There is a slight issue with having to refocus all the time but when you concentrate on some fuzzy blob, you see the change in contrast when you change magnifications, even though the image is not perfectly focused. This gives you an ability of very quickly and easily changing the views through your telescope to see which one fits the situation the best, and I think this is one of the main advantages of any zoom eyepiece. The eyepiece itself is quite bulky and heavy (when compared to standard 1.25” eyepieces), which on its own is ok - you get a good sense of its build quality and heftiness - but it becomes a problem when you want to use the eyepiece with some more basic, entry level telescopes. For instance, I have a Skywatcher 114/900 with a plastic 1.25” rack-and-pinion focuser and it really struggles with the Hyperion Zoom. The eyepiece is so heavy that it bends the focuser tube this way and that way and upsets the balance of the whole setup considerably. This means that perfect collimation, is, at this point, really unimportant. I have yet to try the eyepiece in my Firstscope 76, but I reckon it will handle the eyepiece a bit better, because its focuser feels slightly more robust. Upsides “5-in-1” zoom concept No need for eyepiece swapping Zoom ability lets you find the ideal contrast magnification Decent build-quality, big and robust Wide range of accessory (adaptors, eye cups) Good contrast and sharpness, comparable to fixed focal-length Hyperions Smooth zoom action, even in low temperatures Good eye relief Good for afocal projection No inside reflections Downsides Narrower field of view with low magnifications Inability to use 1.25” filters with 2” adapter More expensive than regular eyepieces Dirt inside the optics can get into focus, which is really annoying Apparently can freeze solid in sub-zero temperatures (not proven) Heavy Not suitable for entry-level telescopes
I have decided to buy a red-dot finder when I was finally fed up with not knowing which star the telescope is actually point at, due to my right-angled optical finder scope. Most of you probably know how confusing a view through a finder scope can be, especially when you are pointing at a rich star field with most bright stars being roughly the same brightness. This becomes an issue when you want to starhop to your destination and you choose fairly dim star as your starting point. This is no big issue with a simple straight-through optical finder, because you can align the star to a centre of a cross with both eyes open. However, this becomes a problem with right angled finder scope, due to the reasons I mentioned earlier. So, to get the initial star hopping alignment more easily, I decided to get myself something that would help me with that. Since using two optical finders seems idiotic, I thought that some kind of projection finder scope would be in order; two options came to mind – either getting a Telrad or Rigel finders, or getting a simple, though much cheaper, red-dot finder. Since I just wanted a simple solution, red-dot finder it was. I have chosen the Baader Sky Surfer III finder, primarily due to its ability to regulate the brightness of the projected red spot, which seemed handy. When I finally got it, it has occurred to me that there might be a problem – I wanted to use the red-dot finder the same way I use my optical finder, and that is, removable with a simple turn of a screw (no literary pun intended). However, although the body of the finder could be mounted to a plastic mount with a typical Synta mounting end, there was no mounting shoe supplied with it, and since I wanted to use both red-dot and optical finder at the same time, I had to purchase a mounting shoe separately. Other mounting options were pretty much permanent ones, which is not really practical when you regularly transport your telescope. When I got the red-dot finder finally set up on my telescope, I have noticed that the projected red-dot is not working perfectly when turning around the brightness adjusting on/off button. It was regularly working, and then not working. Even though I changed the battery, the problem persisted, so I was frustrated and ready to send the finder back to the supplier. And then I though, since it had cost me only the equivalent of some £9, I just thought „to hell with it“, and decided to try and fix the problem myself. As it eventually turned out, one of the cables inside the electronics was faulty, so after replacing it, the finder scope finally worked as it should have, although it did not give me any confidence in this finder’s build quality. Furthermore, there are no dustcovers for the finder, which means that you will occasionally have to remove the dust from the projection lens mechanically, or, as I did, make some dustcovers on your own. After you finally get the red-dot set up and working, you should align it with your scope during the day, because, the adjusting screws for both axes work a bit awkwardly. You have to combine adjusting with your thumb with a screwdriver, which seems complicated enough, and now try to do that at night. Luckily, once you align it, it stays aligned quite well, and some occasional deviation from the alignment is no biggie, since the finder scope does not magnify, and is basically for rough alignment. So, setting it up, getting it to work and aligning are quite complicated processes, but once done, you are ready to go and basically no additional tweaks are needed. I like the way the red-dot finder is easy to use – you just turn it on, align the projected dot with what you want, and turn it off again. Nice and easy. The combination of a red-dot finder and an optical finder is unstoppable, and using the two in tandem allowed me to find objects that were too complicated or confusing to find using the starhopping method. Upsides Simple to use, intuitive Great in combination with an optical finder Adjustable brightness of the projection dot Battery life Range of mounting options Very cheap Better than those plastic 30mm optical finders Downsides Poor build quality Difficult to align Difficult to set up The plastic mount flexes a bit No dust covers Projected dot poorly visible in daylight