"The Orion Halley's Comet Special: OmniVista 60 on vintage alt-az mount"
Now I trawl Astromart, the local Craigslist and even e Bay, and do occasionally come across gems for cheap. Most scope sellers are pretty savvy these days and vintage scope (especially complete outfits such as the 60's and 70's produced Unitron's, Sear's, JC Penney's (most of these either Towa's (Circle T), Vixen's (Circle V) and Park's can cost anywhere from $100 to $400 bucks a pop. Yup these "heirloom" quality 60mm long focal length (most come in at between 700 and 910mm focal lengths) are more expensive when they come complete in their wooden box holders, equatorial mounts (some even with clock drives) and a full complement of accessories (mostly 0.965" eyepieces, 2x barlow lenses and moon and sun (sic...these should never be used and should be smashed and thrown away ASAP). One dead giveaway to their 60's and 70's heritage is their metal focus knobs, something rarely seen these days in small 60, 70 and 80mm scopes.
Anyway to cut the story short, while browsing e Bay one lazy Saturday morning, I stumbled across a very familliar looking scope. Now where have I seen this cute lil short tube...oh yes in an ad in my 1985 Orion Telescopes catalog! This scope was released during the Halley's Comet fever era, and was sold on a flimsy looking tabletop tripod, but came with a spring loaded 6x30mm finder, 1.25" rack and pinion focuser and screw on prism diagonal. The scope also came with two 1.25" eyepieces, a 28mm and 15mm. Price back in the day was $229. The one I found did not come complete, the OTA that is. This set is partially complete as the previous owner mounted it on a vintage yoke mount that has slow motion controls in both altitude and azimuth (nice mount by the way). I will have to do a little research on when slow motion controls in azimuth was removed from these small scope mounts. My guess is sometime in the late 80's. The current crop of chinese and taiwanese made small yoke mounts do not have this option. All they have is slow motion controls in the altitude department.
"As the late Steve Irwin would say "Isn't she a beauty"
When released in the mid 80's, the scope did not have a name. I did a little more snooping around on the internet and found out that Orion had indeed given this sweet lil scope a name....Orion OmniVista. I can't find any ad's for this so I am not sure if it was sold as just an OTA or with the tabletop mount as back in 1985. Anyone out there with vintage Orion Catalog's e mail me if you have a copy of this ad!
The OTA itself is very solidly built, and I dare say more solidly built than most of its longer tube brethren. This 20" OTA weights in at a hefty 3.2lb, and this is the OTA alone. The metal retainer ring for the main objective, which only looks to be fully coated (blue reflections only) has the aperture and focal length inscribed onto it (aperture 60mm and focal length 420mm-f/7). The scope, in its native form, comes with a spring loaded, dovetail (non standard and does not accept the current dovetails from the chinese finderscopes....the dovetail is smaller and slips in from the front, with a lock knob down the front too) 6x30mm finder (which is absent in my sample, which comes with a holder that looks like it came from one of them Meade ETX's, but no finder). The focuser knobs are huge for a 60mm scope and are a very sturdy plastic. The rack and pinion focuser is very precise with no play when you rack it in and out of the focuser. It also comes with a focus lock, which will come in handy when you use it for wide field imaging.
"Looking down the barrel of the scope...the business end"
Looking down the business end, I do not see anything that would suggest that the main objective is stoppered down. There is nothing immediately behind the objective. Also looking through the focuser end of the OTA, I can see the objective in its entirety when racking the focuser in and out all the way, suggesting that there is no light cut off from the tube being too short, or the focuser being too long. One quirk of the OTA though is its diagonal. This OTA does not accept the standard 1.25" diagonals (even though it has a focuser in the 1.25" format). What is does have is a thread (not 1.25", appears a little smaller) for the prism star diagonal to screw on that comes with the OTA. I was bummed by this, but upon testing, the prism diagonal seems to work very well with the OTA.
"Aperture=60mm; Focal length=420mm, fully coated optics only"
In the Field
Preliminary inspections out of the way, now it was time to test the scope to see if it performs as well as a 60mm scope should. One problem I often encounter with refractors is miss collimation resulting in imperfect airy discs. A good refractor should have very tight airy disc and the expanding disc should look identical on both sides of the focus. Testing the scope on the stars, the OTA exhibited perfect airy discs and pinpoint stars at the focus point!
"I could get used to this...slo mo on azimuth....something only found on older mounts"
Since I did not have a working finder on the OTA as of yet, I eyeballed bright test objects. In two suburban testing sessions, I observed the 90% illuminated moon (about 1 days out from full moon) and a 4 days past opposition Mars in the evening sky; as well as Saturn and Venus in the predawn sky. I had trouble bagging deep sky objects from my light drenched skies, and the lack of a finder made things even more difficult. Will have to update this blog when I do get the scope under darker skies!
"Slo-mo altitude adjustment, the standard found on todays chinese alt-az mounts"
I used my 24.5mm Meade SWA eyepiece, working at 17x magnification as the finder eyepiece, my 20mm Orion Expanse, working at 21x and my TeleVue 6mm Radian, working at 70x, as my high powered planetary eyepiece. This lil beauty is definately a keeper. Planets were nice and sharp, as was the moon. I had superb, if warm yellow'ish views (typical of fast achromats) of Saturn and its rings, and though I could make out Cassini's division when the seeing steadied. Venus looked very good at 70x too (Seemed to be the best magnification for sharp color free views). I also pushed the magnification above the 60mm maximum limit of 50x per inch with my Orion Shorty Plus barlow to 140x, but CA became a problem and the views dimmed too much. I also used the scope for the total lunar eclipse (14th of April 2014) and even caught some quick looks at a rather featureless Mars at the same magnifications as above. The planetary disc was very sharp though.
"The focuser end showing the screw on metal thread for the prism diagonal"
The mount is of an older vintage as well. This is not a standard issue with this scope, but was a joy to use. There is still that annoying offshoot that one needs to figure in with the altitude adjustment, but I really liked the slow motion control in azimuth. First time using this function on such a small alt-az mount! The flimsy wooden legs are best fully collapsed or extended to about midway since it shakes too much when fully extended. It also comes with one of those triangular plate trays that attach to the mount with wing nuts. I find it easiest to leave one attached to the mount so I can collapse and carry the mount.
All in all I think I got a great bargain for $50 bucks. This scope seems to be a keeper, but only time will tell if I decide otherwise.....
