11/14/2023 0 Comments Orion starblast 4.5 eq reflector![]() What’s more is that the whole finder, including seemingly even the objective, is made of plastic. A 5×20 finder is already a terribly small instrument-barely able to show you anything in the sky at all-and this one makes matters worse by adding its own miniature 45-degree erecting prism, which gobbles up the finder’s already feeble ability to gather light. It really should be replaced by a quality 90-degree mirror or prism star diagonal. The diagonal not only has a nearly all-plastic build, but the prism induces annoying diffraction spikes on bright stars and planets, reducing the already-low image quality even further. This prism makes for upright and non-reversed images (you can read a newspaper looking through it, unlike a normal star diagonal, which will show a mirror image flipped left-right), but at the expense of viewing comfort and image quality. The included diagonal is a 45-degree erecting prism design. Despite this, Orion actually makes a point in their advertising to brag about their supposed quality, calling them “quality Kellner eyepieces (not cheapie ‘H’ eyepieces like with most other brands)” when in truth they are not quality and are only slightly better than the Huygens eyepieces included with some of the really cheap scopes on the market. ![]() They have a rather narrow field of view (less than 50 degrees) and seemingly internal reflection issues. The included Kellners seem to be mostly plastic and lower in quality than the kit Kellners often supplied with many inexpensive telescopes. Don’t bother the Barlow is good but of no use on such a low-quality telescope, and the flashlight is really cheap. Orion sells a kit that adds a 2x Barlow and a dinky red flashlight. The StarBlast 90 comes with two eyepieces: 25mm and 10mm Kellners providing 20x and 56x, respectively a 45-degree erecting prism a 5×20 finderscope and Orion’s MoonMap 260. Lastly, the telescope attaches to its tripod with a standard ¼ 20 threaded hole, meaning it’s possible to easily install it on a photo tripod, or bolt a dovetail on to attach it to a real quality astronomical mount (not that that would likely be worthwhile). I have absolutely no idea what it is doing on this telescope, but it is utterly pointless and it would’ve been wise if the manufacturers put the money spent on it into some of the other, more lacking areas of this instrument. Unusually, the focuser also has a bubble level and compass built into it. However, the one on the StarBlast is definitely one of the worse ones, as it wiggles a lot as you rack it in and out, which is a real nuisance. ![]() Like many scopes in its price range, this focuser is unfortunately all-plastic. ![]() The StarBlast uses a 1.25” rack-and-pinion focuser. Holding on by a tiny strip of plastic, it’s only a matter of time before it breaks and leaves your cap on the ground, and quite possibly on snow or wet grass. Unusually, this scope has a lens cap that remains attached when it is taken off of the front. There also seem to be a lot of issues with stray reflections and glare, probably caused by poor interior blackening and baffling. That’s a wonder, really, since it is kind of hard to mess up a cheap refractor objective. The images are just not very sharp, even at low powers, which seems to be due to a poor job in the manufacture of the lens itself. The telescope, unfortunately, has some other optical issues that are a little less expected and a lot more troublesome. This means that the scope is in practice limited to rather low magnifications the images quickly become fuzzy at high powers, and, of course, the Moon, planets, and bright stars will have ugly purple halos around them. At f/5.6, the scope is going to, of course, have a lot of chromatic aberration, and the StarBlast does so as expected. The StarBlast 90 is a 90mm f/5.6 achromatic refractor.
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