Telescope Reviews

Page 9 By Ed Ting Updated 12/4/00

Click on a scope below:
  • Celestron CM 1400 SCT
  • Intes MN56 Mak-Newt
  • Starmaster 10" EL Dobsonian
    Celestron CM 1400 8/6/99 (14" f/11 Schmidt-Cassegrain, CI 700 mount, drives, 26 mm Plossl, 9X60 finder, about $6000 street) Is there any astronomer out there who hasn't thought about owning one of these? As the granddaddy of the king-sized Schmidt Cassegrains, these C14 scopes have a long and rich history. Early versions were white-tubed and were fork- mounted. Later came the orange tube versions, also fork-mounted. While these scopes generally had a very good reputation optically, mechanically they have had always been unwieldy. You practically had to be The Incredible Hulk to hoist the massive tube/fork arm/drive assembly onto the tilted wedge, and in the dark, no less.
    C14 An older, orange-tubed C14 Thanks to Dave Jurasevich for photo
    In the mid-1990's, Celestron brought these scopes into the modern era by pairing the tube (now painted black) with Losmandy's excellent G11 German Equatorial mount. These were called CG14s. For 1999, the C14 gets a slightly modified (cheaper) version of the G11 called the "CI 700." All the newer (black-tubed) versions are lighter (the OTA now weighs only 49 lbs), simpler, studier, and more elegant. They are also easier to balance for photography. A reader from the NYC area who was vacationing in New Hampshire called me up one evening to ask me to evaluate the scope (a man who takes a 14" Schmidt-Cassegrain with him on vacation is my kind of guy!) Unfortunately, circumstances beyond our control meant that the scope didn't get set up until well after dark, so I couldn't take a picture. ...which is a shame, because you really need a photo on a review like this. As you might suspect, the scope is massive. After assembling it, one's inclination is to step back and just admire its sheer physical size. It looks like a C8 on steroids. The scope assembles in about 15 minutes. Subjectively, it is slightly easier to put together than Meade's 178ED 7" refractor. There are 2 chrome handles on the back of the scope, which are a godsend. The mirror is heavy enough that Celestron advises you to lock the mirror in place using two locking screws on the rear of the scope before transport. The "CI700" mount is very sturdy, but I found a few items on it that deserve mention. In short, the CI700 is a cheaper version of the G11. The head appears to be the same, but the tripod uses spreader bars instead of the molded-in flanges on a G11. The CI700 legs are thinner than the ones on the G11. Also, the control box is permanently mounted on a half-pier, and the RA cable attaches to a flimsy-looking connector atop the box. One of the mount's allen bolts passes perilously close to this flimsy connector, and to me it's just a matter of time before it breaks off (the G11 uses the sturdier phone cord-type connectors for the RA and Dec cables.) The nice RA and Dec clutch/tension knobs on the G11 are replaced by locking bolts placed in non-intuitive locations. I'm sure I'd get used to them over time, but on this night they confounded me every time I needed to use them. Finally, the hand paddle was broken on this sample. Once past these niggles, however, the mount functioned just fine, and with the right tension on the axes, I found the motions of the scope "Dobsonian-smooth" and didn't even miss the absence of the hand paddle. I should also mention that, unlike the G11, the CI700 does have manual slow motion controls. In case you haven't done the math, this telescope has a 3910 mm focal length. For someone accustomed to a 4" f/8 APO, this took some getting used to. A 32 mm Plossl yields 122X, and a 7 mm Nagler makes a whopping 558X. My first target was M13 and I let out a little gasp when I found it. The light-grasp, resolution, and sharpness were superb, much better than I had expected. A quick star test revealed excellent spherical correction, although it was hard to make exact quantitative estimates due to a slight mis- collimation of the optics. We toured most of the familiar summer objects, including the Ring, the Dumbbell, M8, M20, Albireo, Epsilon Bootes, and a few of the brighter galaxies in Ursa Major. In each case, the image scale of the objects surprised and delighted me. M82 was huge and detailed with a 22 mm Panoptic (178X.) The Dumbbell showed an impessive amount of detail at the same power with an O-III filter. The Ring Nebula was more like a disc than a ring. On the moon, we kept pumping up the power until Clavius filled the field of view at 558X in the 7 mm Nagler. The image held up better than you might think. Drawbacks? Besides the obvious -size, weight, and cost- the long focal length and narrow field of view may make some observers feel a little claustrophobic. You are pretty much trapped into using medium or high power. The owner of this C14 doesn't have any other telescopes, and I joked to him that one day he is going to wake up in a cold sweat dreaming about a TeleVue Ranger. Also, you will need a small step stool to reach the finder at certain positions. If you can live with the above concerns, however, this King Kong- sized SCT comes pretty close to being an Ultimate Telescope. Its long focal length will please double star and planetary observers, and it gathers enough light for deep sky fans. About the only thing it won't do is provide wide field deep sky views. Finicky observers might want to buy the C14 OTA and a G11 separately, and mate the two together, or locate a used CG14 unit. An extra finder or two wouldn't hurt either. An excellent telescope. 2) Intes MN56 Maksutov-Newtonian 8/6/99 (5" f/6 Mak-Newt, 6X30 finder, tube ring, $795) There seems to be an endless variety of these Russian Maksutov-based scopes out there. I have trouble keeping them all straight in my head. This one is the 5" f/6 unit, one of the versions you cannot get under the "Argonaut" name from Orion. It's compact (13 lbs), and looks like an MN61 (reviewed elsewhere) that's been left in the dryer too long. The finder is mounted on a sturdy stalk and has two mounting locations on the tube. A metal plate screws off the back and exposes holes drilled into the back plate, to help hasten cooling. The sample tested was a loaner from Bill Burnett at ITE. Bill had given the scope to Todd Gross, who forwarded it to me after raving about it. Click here to get Todd's review of this same sample.
    MN56 The Intes MN56, on the GM-8
    Hybrid catadioptric scopes like these used to be curiosities, but they're relatively mainstream these days. Briefly, a Maksutov- Newtonian is similar to a normal Newtonian, but with a Maksutov corrector plate in front. The small (23.6%) central obstruction and the lack of a secondary spider do a good job of fooling you into thinking you're looking through a premium refractor. We used the scope over several nights mounted atop a Losmandy GM8. We compared it to several scopes, including a Takahashi FS102 and a few light buckets. Optically, the scope is outstanding, just like its big brother, the MN61. We looked at the usual summer Messier objects and several doubles, including Pi Aquilae, Delta and 52 Cygni, Albireo, Epsilon Lyrae, and Pi Cephei. In each and every case the MN56 at least equalled the performance of the FS102, and in a few cases, the MN56 was actually a little bit better. If you looked very closely, you might discern that the FS102 had a tiny edge on contrast at certain times, but I don't think anyone would notice unless you had the scopes set up 5 feet away, the way we did. The scope threw up wonderfully contrasty and sharp views of deep sky objects. I found all of the Messier objects in Sagittarius, Scorpius, and Ursa Major. Globulars like M10, M12, M13, and M92 looked great, even at higher powers. One hallmark of a good telescope is its ability to absorb stupid-high powers, and the MN56 is no exception. It likes the 2.5 mm Lanthanum (305X) and the scope looked as if it could handle perhaps a little more. In theory, an obstruction of any size (even the stingy 18%-23% obstructions on the MN61 and the MN56) will degrade stellar images be transferring the energy from the airy disk out to the diffraction rings. This has the effect of lowering contrast and in general "muddying" up the image. However, in practice, these Mak-Newts work so well that I think anyone shopping for an expensive APO should at least look through one of these before dropping the long green for a refractor. The MN56's star test was excellent. I have trouble discerning spherical aberration once it gets to about 1/8 wave or so, and wasn't sure I could see much wrong at all in the star test on this unit. ITE inspects each unit that it ships, so you should be in good hands (this is important on imported scopes like these.) In reading over what I've just written, I've probably just sold a bunch of these for the Intes dealers out there. However, before you whip out those credit cards, there are a couple of things you should know about. First of all, the finder is just awful. It isn't sharp, you can't see the crosshairs, the eyepiece has zero eye relief, and the focusing mechanism is so loose it goes out of focus if you so much as touch it. Had the scope been mine, I would have chucked the finder into the woods on the first night. On the second night, I installed my own 6X30 Vixen finder into the bracket, which lowered my blood pressure several points. Luckily, though, this scope is so cheap, you'll have plenty of money left over to get a good finder (ITE says that users can upgrade to a 7X50 finder or a Telrad for about $50.) The scope has a helical focuser, which although well-made, was mildly annoying. Also, the focus plane lies so far above the tube that the TeleVue eyepieces I had wouldn't come to focus even with the drawtube fully extended. I had to raise the eyepieces off the focuser and clamp them with the set screw. It's fair to point out, however, that another observer present said none of this bothered him. (ITE says that with Orthoscopic eyepieces, or the Clave Plossls, the scope will reach focus without extending the tube.) Finally, as the scope has the visual appeal of a brown paper bag, it is unlikely to instill the pride of ownership that an expensive APO will. Readers should also note that the tube ring is drilled for a GM8/ G11 or an Astro-Physics plate. It also mates with the plate that Orion sells for its Sky View Deluxe mount, so you can use the scope with any of the cheap Taiwanese-clone mounts (Sky View Deluxe, HD, Spectiva, LXD300, Starplitter GEM, Discovery, etc.) You'll need another counterweight. If you use one of the Vixen mounts (the Super Polaris, Great Polaris, or GP-DX) however, you may have to do some creative drilling or tapping and get another counterweight. I feel like a dolt complaining about these items on a $795 scope that performs this superbly, but they did come up. Once you have the issues of the finder, focuser, and mount sorted out in your head, you are all set.
    MN56 Close-Up View of the cooling holes. Normally, a plate covers this up.
    I think anyone looking for an APO in the 4"-7" range should seriously look at these 5" and 6" Mak-Newts. The MN56 is so cheap, you can buy one, get a luxury finder like the Tak- ahashi 6X30 unit, pick up a used GM-8, and have a killer rig for about $2000 (about the price of a 4" APO OTA.) This MN56 is, in short, a telescope with super optics, quirky mechanics, plain-jane looks, and is a major bargain. In other words, it's a typical Russian scope. Okay. Now whip out those credit cards. Intes MN56 Hots
  • World-class optics
  • Bargain-basement price
  • Sturdy, overbuilt construction Intes MN56 Nots
  • Ugly
  • You'll need to get a new finder
  • ...and possibly a new focuser as well The Verdict
  • Performs like Meryl Streep, looks like Jack Klugman 3) Starmaster 10" EL Dobsonian 10/4/99, 12/4/00 (10" f/6 Truss Dob, light shroud, JMI focuser, was $1995, now NLA) (11" f/5.4 version also available at $1995) From woodworker Rick Singmaster and master mirror-maker Carl Zambuto comes this innovative Dobsonian. The upper truss assembly, light shroud, and the truss tubes are one solid piece. While this makes the scope somewhat bulkier than your average truss-type reflector, there are a couple of advantages. First, the scope retains its collimation after many assembly/disassembly cycles. Also, the setup time is very quick -- you screw down four bolts and start observing. Starmaster claims a setup time of one minute, which sounds about right.
    Starmaster EL Let's Go Embarrass Some Refractor Owners! The 10" Starmaster EL
    I had some very encouraging views through this telescope at Astrofest 1999, and was going to request a review sample, when a fellow club member saved me the trouble and bought it. Looking at the scope, it's clear that Rick Singmaster didn't graduate from the "less is more" school of thought when he made these ELs. The scope is big, bulky, and heavy. It weighs 67 lbs assembled, and is almost as large as my 12.5" Orion DSE (many of Starmaster's telescopes are somewhat larger and heavier than their premium-Dob competitors.) However, this increased mass translates into better stability at high powers. I won't mince words here: This is an awesome telescope. At Astrofest, I could not find anything in the field that was significantly better, at any price level. I do not know what Carl does to these mirrors, but I can say that every Zambuto-equipped telescope I have ever seen has been a real stunner. I have trouble tearing myself away from the eyepiece. After viewing this sample, many club members have gone and placed orders for themselves. In fact, the owner of this 10" model was so impressed, he went ahead and ordered one of the 11" versions as well. Excellent reflectors like this one are going to serve as a wake-up call to those who thought they needed an expensive refractor to get images this sharp. I felt as if I could look at the Double Cluster with the 35 mm Panoptic all night if I wanted to. Ditto for Jupiter and Saturn with the 13 mm Nagler later in the evening.
    Disassembled Starmaster The EL, disassembled
    Drawbacks? Aside from the size and weight issues, the JMI focuser seems placed for TeleVue eyepieces, which take an unusually large amount of out-focus travel. This is fine if you use TeleVue eyepieces, but if you use orthos, like the ones from University Optics or Pentax, there is not enough in-focus travel to accomodate the units with focal lengths shorter than about 12 mm. Other than that, I am hard-pressed to find any faults with this handsome, super-sharp telescope. Unfortunately, as with any premium telescope these days, there is an availability issue. If you have read this far and think you want one, it may already be too late. Carl Zambuto made an initial run of ten 10" mirrors, and the scopes they went into are already sold out. A run of ten 11" mirrors (same focal length, same size and mechanics as the 10" units) is due out near the end of 1999. I understand Carl has committed to do another run of ten 10" mirrors. After that, there may not be any more. It's a shame -- Thirty telescopes of this level of quality does not seem like nearly enough for the astronomical community. If you want one, act quickly, and accordingly. Starmaster Responds, 10/4/99: According to Rick Singmaster, these scopes will continue to be made as long as the public wants them, in lots of ten. Based on my past experience, however, you may have to wait a while for your Zambuto mirror. I would still advise you to move quickly if you want one. Also, Starmaster states that there is about 3/4" of collimation travel in the main mirror. Users can move the mirror back or forward to accomodate differing eyepieces. This is said to be a two-minute operation. Rick admits that the scopes shipped are optimized for TeleVue eyepieces. End Telescope Reviews, Page 9
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