Four years ago, Orion® introduced the StarBlast?, a 4.5-inch f/4 Newtonian on a mini-Dobsonian mount. Although 4.5-inch Newtonians are popular beginner?s scopes, this one was different: instead of the typical long focal ratio (f/8) spherical mirror, it had a short focal ratio (f/4) parabolic mirror. This gave it better image quality in a package half the size. The single arm Dobsonian mount was simple to operate and very solid, as compared to the equatorial mounts sold with most 4.5-inch Newtonians.
The reviews of this little telescope were very positive. The telescope had been marketed as a kids? telescope, but after the reviews came out, many adults bought these scopes because of their optical quality and portability. In fact, I was one of the early purchasers of the classic StarBlast?. I remember taking it to a public star party sponsored by my astronomy club, and ending up with a long line of viewers who were taken by the small size (and price) of this scope and by the fine image of Jupiter and its moons that it was delivering.
The main drawback of this scope, shared by all so-called ?table top? telescopes, is that it is hard to find a table top suitable for supporting it. Most tables have four legs, which makes them unstable on all but the most level surface, and few are solid enough to support a telescope magnifying a hundred times or more. Also, the table needs to be pretty small, so that you can approach the telescope from different directions, depending on where it is pointing in the sky. This problem was discussed by StarBlast? owners on online forums, and various solutions proposed and tried out. The ideal support would probably be a three legged stool, but such things are hard to come by.
Recently, the folks at Orion® came up with a different idea, what they call the ?adult? version of the StarBlast?. This replaces the original Dobsonian style mount with their smallest equatorial mount (on a tripod), the EQ-1. This raises the scope to a suitable height for adult observers. Another change is replacing the 17mm and 6mm Explorer II eyepieces provided with the original with 15mm and 6mm Expanse? eyepieces. These offer a wider field of view (66° vs. 50°) and longer eye relief, making them easier for eyeglass wearers to use (see below). I was recently loaned one of these scopes to review.
The StarBlast? EQ comes well packed in a single cardboard carton. Assembly was similar to other small telescopes, and took about half an hour, following the detailed and well illustrated instructions which Orion® provides. Orion® includes a neat little collimation cap, which showed that the telescope was slightly out of collimation, but was quickly corrected following the instruction manual. This collimation cap is a neat little device which works much the same as a more expensive Cheshire eyepiece. Keep an eye out for it while unpacking, as I?ve heard of at least one buyer throwing it out by mistake!
The optics on this equatorial version proved to be as good as in my ?classic? version. A star test using Vega showed clean concentric diffraction patterns consistent with 1/4 wave correction with only a slight hint of surface roughness. The new Expanse? eyepieces gave pleasing wide vistas. The tripod on the equatorial mount raises the telescope to a comfortable height for ?sit-down? observing, though the controls are harder to operate in the dark than the original StarBlast? mount. The EZ Finder II red dot finder made it easy to locate objects.
I particularly enjoyed my views of large objects like the Pleiades (Messier 45) and the Andromeda Galaxy (Messier 31), along with its companion galaxies Messier 32 and Messier 110. The glittering jewels of the Double Cluster in Perseus were absolutely spectacular in this scope. The 2.2 degree field of view of the 15mm Expanse? eyepiece gives wide vistas simply unobtainable on most other telescopes. It?s these wide-field low-power views offered by the StarBlast? that have made it so popular with many experienced amateur astronomers. Unfortunately, neither the Moon nor any bright planets were available when I was testing, but I know from previous experience that these optics are capable of delivering pleasing views at 125 power or more on these objects.
Though I think my first choice would still be the Dobsonian mounted version of this scope because of its simplicity of use, the EQ version is also an excellent choice either for a beginner or for an experienced amateur astronomer with a larger more powerful scope who wants a compact lightweight grab-and-go scope which will afford wide vistas of sky, yet is also capable of pleasing views of the Moon and planets.