Jeremy's almost but not quite entirely moribund blog

Friday, January 06, 2006

Review - Orion Starblast 4.5EQ Telescope

Well, I finally took the plunge and bought a telescope--an Orion Starblast 4.5EQ. This scope combines the tube from Orion's famous Starblast Astro "mini-Dob" with an EQ-1 equatorial mount, and it also upgrades the eyepieces to the "Expanse" line to take better advantage of the scope's wide field ability.

I figured the scope would be a good compromise between aperture and portability--big enough to let me see some deep space objects, but small enough to pack along on our family trips out to the country. And the tube is just about the right size, but the mount is bulky and awkward and doesn't collapse well, so it remains to be seen if I'll be able to fit it into our compact car with all the kids and stuff. I might have to partially disassemble it to do it.

Speaking of assembly, the manual is a little inadequate. Assembly instructions are a little vague, referring to several parts by name without clearly identifying them. There is a picture, but it has a dozen arrows pointing at it and it isn't clear what's what. Also, the packaging must have changed somewhat since the manual was printed, because several parts weren't where the manual said they were. For instance, the manual said to remove the bolts from the tripod legs, install the legs on the mount, and then replace the bolts--but the bolts weren't on the tripod legs to begin with. They were in a little bag.

Once I found all the parts and made sense of the instructions, though, everything went together well. The mount operates smoothly and seems reasonably sturdy. The slow-motion controls make it quite easy to center the target in the eyepiece. I just have one complaint about the mechanical operation of the mount: the counterweight shaft gets in the way of the right ascension cable fairly often. Speaking of which, the R.A. cable can be attached on either side of the mount--"whichever is most convenient", the manual says, which can be translated as "you'll find yourself moving it from one side to the other several times per night (don't drop the thumbscrew in the grass)". With the scope pointed south, I have to disconnect the cable entirely because it's blocked on one side by the counterweight and on the other by the OTA. Maybe I should have just gotten a Dob. ;)

Enough about the mechanics; it's time to talk about the optics. Fortunately, the telescope gods smiled upon me and I was blessed with clear skies the first two nights after my scope arrived. (Tonight, the third night, is cloudy, which is why I'm typing this review instead of looking at the stars.) This is my first telescope, so I don't have much of a frame of reference to compare it to other than my $30 Simmons 10x50 binoculars (which, though cheap, were great for introducing me to the sky, although difficult to hold steady).

The Starblast 4.5EQ comes with two eyepieces, a 15mm and a 6mm Expanse (mine are actually labeled Ultrawide, but I've read they're the same thing). In conjunction with the 450mm focal length of the scope, these yield 30x and 75x magnification, respectively. Eye relief is good--I can look through either eyepiece with my glasses on and see a wide field. The 6mm EP is prone to "blackouts" if I'm not looking directly into it, though.

The first target I pointed at (after my abortive attempt at polar alignment) was the waxing crescent Moon. It was stunning! The clarity and contrast blow away anything I've seen before. Mountains and craters popped out with stark relief. I might have to invest in a lunar filter, though, since even at about 1/3 full, it was uncomfortably bright.

Next on my tour was the Pleiades. They took a bit of effort to find, but once I did, I wasn't disappointed. I didn't see any nebulosity (I imagine I'd have to go to a dark sky site) but I did see an awful lot of stars--many more than I could see through binoculars.

I swung around to the Orion Nebula and the view was quite nice. The small white fuzzy blob I remember seeing in my binoculars was... well, a bigger fuzzy white blob, but a very pretty one. I could make out the shape pretty well, but I knew enough not to expect to be able to see colors like you see in long exposure astrophotos.

About this time I realized Saturn was up, so I took a look. I was a little disappointed--Saturn was miniscule. Switching to the 6mm eyepiece upgraded it to maybe just tiny. Before I bought the scope, I read a review where someone wrote that the Cassini division was easily visible. I'm guessing he used a much nicer eyepiece than the stock units and/or a Barlow. I couldn't see the Cassini division at all, although I could easily see the gap between the planet and its rings. I'm not sure how many of Saturn's moons, if any, were visible, because I was too busy staring at the rings to look for them. To be fair, the seeing wasn't very good--Saturn visibly shimmered at 75x, so maybe the Cassini division would be visible under better circumstances. I'm tempted to get a 2x Barlow to help things out a bit.

Early the next morning, I took my scope out and looked at rising Jupiter. The four Galilean moons were easily visible. No surprise there, since I could see those just fine with my binoculars (assuming I could hold them steady enough). Jupiter itself was a featureless white disc for the most part, but I think I caught a fleeting glimpse of the cloud bands once or twice.

Next I decided to point at the Mizar/Alcor double in Ursa Major. I remembered reading that Mizar itself is a double, and I wondered if I'd be able to see it. The answer is: yes, easily. Comparing what I could see with the Starry Night software, I found that 10th magnitude stars were visible.

I have yet to catch Venus--it's pretty low in the sky now, so I might not be able to see it for a few months. I almost saw it yesterday evening, but it ducked behind clouds just as I found a line of sight between the trees, houses, and power lines.

Perhaps tomorrow I'll look at snowcapped Mt. Timpanogos and see how my scope performs on terrestrial objects. Upside down, obviously, but my real intent is to get the finder scope aligned properly by pointing it at something that doesn't move. It's been a little touch-and-go thus far, as I've had to hunt a bit before I could bring what the red dot pointed at into the eyepiece.

All in all, I'm happy with my new scope. The mount is a little awkward, but works smoothly (when the counterweight shaft doesn't interfere with the R.A. cable, anyway). It's not quite as portable as I'd hoped, but it's not too unweildy either. I'm no expert, but the optics look great to me. The moon is spectacular. Stars are crisp and bright. The focus is a little touchy, though--it can be difficult to get the image just right. The wide field view takes in a lot of sky, which is nice for deep sky objects (can't wait to see Andromeda from a dark sky through this scope) but not ideal for planets.

UPDATE - Feb. 8 2005

I've had the scope for over a month now. I still take it out just about every clear night (and many clear mornings). I got an Orion Shorty 2x Barlow, and that helps with lunar/planetary viewing. Some new observations:

  • Jupiter - I could see four cloud bands pretty well. The Galilean moons are, of course, easily visible, though they appear starlike (I can't resolve them into discs).
  • Mars - I got my scope too late for the opposition. Mars is just a little orange ball, but I think I might have glimpsed Syrtis Major.
  • Saturn - On a night of good seeing, I could easily resolve the Cassini division. I even dragged my wife out and she saw it too. It was visible even without my Barlow (at 75x).
  • Venus - Seen as a beautiful crescent in the early morning sky.
  • Andromeda Galaxy - I could only see a faint smudge of light, but I haven't had the chance to see it from a dark sky site yet. My best view of the galaxy still belongs to my 10x50 binoculars.
  • Orion Nebula - Recognizeably the same thing as you see in astrophotos, though faint, colorless, and not as expansive. The four stars in Trapezium resolved nicely.
  • The Moon - This telescope has unfolded a whole world up there! With good atmospheric conditions, the scope provides crisp, bright views at 150x that make it look almost like you're peering through the window of the Apollo CSM. Mountains, "seas", and countless craters just pop out at you.

    Here's a photo I took through the eyepiece:


  • Thanks so much for the review. I just got the StarBlast as a starter scope for Christmas and will be looking for what you found. I was already happy just to have it, but your blog gave me some specific goals and now I'm really excited!

    By Anonymous Anonymous, at 7:44 PM  

  • It's a good little scope. Now that I've used bigger scopes, I can say that, by telescope standards, the Starblast is not bulky by any means. After all, you can carry it under one arm. It's a breeze. This comes at a price, though--the heavier mounts are much, much sturdier and give a more solid view. But that's the price you pay for grab-and-go simplicity.

    By the way, you're not likely to be able to see the Cassini division in a Starblast any time soon. In the three years since I wrote this review, Saturn's orbit has aligned the plane of its rings closer to edge-on with Earth.

    By Blogger Jeremy, at 9:40 AM  

  • although a bit old posts guys, I still find it useful as I just bought the telescope. Should you have any update on the times you spent with it, I would appreciate that.

    By Anonymous Anonymous, at 3:06 AM  

  • I was thinking of getting a telescope and stumbled upon this post. 5 years later, would you still recommend it to a beginning astronomer? Is Saturn still minuscule, or do better eyepieces solve this issue?

    By Anonymous Anonymous, at 2:02 PM  

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