Some Orion-Brand Eyepieces...and Others
The market is crowded with an array of eyepiece brands and designs, so we think pretty hard about purchases of oculars. The Orion Telescope Center catalog includes a number of products that are marketed under their own brand. And each supplier has a plethora of "tradenames". Things used to be so much simpler when we just had to think about Kellners and Orthoscopics! As you read on, I can only implore that you try to keep the names straight.
I had an opportunity to compare side-by-side two of Orion's products of about equal focal length. I own an Orion MegaVista eyepiece of 10.5mm focal length and had access to an Orion Ultrascopic of 10mm focal length. Another of Orion's products is the UltraScan eyepiece; while I've never used this one, I did talk to an Orion representative about it. A big selling point for any eyepiece is the apparent field of view. Here's how these three eyepieces stack up:
I had purchased the MegaVista to get just the right boost in magnification, while retaining a relatively large field of view. It has a long eye relief (the distance from the eye lens to where you position your eye when observing) and includes a rubber eyeguard as a help in positioning your eye. The eyeguard folds down for those who wear glasses while observing. I compared the MegaVista with the Ultrascopic on my 98mm refractor using the Double Cluster in Perseus. Both provide comparably sharp star images across the full width of the field; in fact, I detected virtually no difference in the quality of the images. The big difference is the field of view and the diameter of the eye lens, which I find makes observing with the MegaVista more pleasurable. The question is whether the added field of view on the MegaVista is worth an extra $49 to you. I had also tried another Ultrascopic of longer focal length a couple of years ago - the images were brilliant and sharp to the very edge of the field. If you're in the market for a relatively inexpensive eyepiece, the Ultrascopic is a very good choice. If you want a larger field of view usually found only in somewhat costlier eyepieces, then the MegaVista has a lot to offer.
With their larger 77o field of view, the UltraScan eyepieces might be dubbed the "poor man's Nagler". Since they have only five elements, versus seven in the Nagler and Meade Ultra Wide Angle, they're considerably less bulky. The field of view in the Orion UltraScan comes pretty close to the higher-priced super wide field oculars, but with fewer elements and at half the cost, I figured it just couldn't be comparable in other respects. In fact, this was confirmed by the Orion representative who admitted that the images in the UltraScan somewhat deteriorate away from the center of the field, especially in a rich-field scope.
Now let's muddy the waters even more. At Astrofest a couple of years ago, I was told by a representative from University Optics that their Wide Scan eyepieces exhibit some falloff in edge-of-field definition. When I later tried one on my f/5.6 scope, the edge defect wasn't that bad, and University's Wide Scan eyepieces provide a very bright, crisp image otherwise. With their larger field of view and price near that of the Orion MegaVista, the University Wide Scan eyepieces are an excellent alternative. This is especially true if you happen to pick one up at Astrofest, where University sells their products at a nice discount.
Orion must be getting lots of favorable word-of-mouth advertising, because their MegaVista eyepieces have consistently been sellouts. (The first time I called, they were sold out. Then I waited awhile longer, only to find that the next shipment was already sold out. This time I placed an order and had to wait three months for mine.) The Orion products appear to be competitively-priced alternatives to other widely-touted designs, with some limitations as noted.
All that said, I conducted an unscientific survey of some of the more active observers in LCAS to find out what are their single favorite eyepieces, "favorite " being defined as the one used most often. Their adjectives included "good eye relief ", "sharp to the edges ", "good color correction ", and "wide field ". Some also noted that if they could afford any eyepiece they wanted, that would probably change their response. The point is, most of us can't always afford what we prefer, so it's worthwhile finding the less expensive eyepieces that people really like. After all, life is a compromise. Notice that the choices tend to be lower magnification eyepieces, and this is the case regardless of the type of telescope used. So here they are, in no particular order:
- Rich Burns - a tie between a 19mm Tele Vue Wide Field for locating objects
- Lesa Andre - 40mmTele Vue Plossl
- Greg Lutes - 40mm University Koenig
- Michael Purcell - 26mm Meade Super Plossl
- Grant Barlow - 32mm Meade Super Wide Angle
- Jeff Inman - 20mm University Wide Scan
- Mike Castleberry - 24mm Tele Vue Wide Field
- Mike Cain - 40mm University Koenig
- Roberto Garza - 25mm Idai Orthoscopic
- And my favorite is a 19mmTele Vue Wide Field.
and a 9mm Nagler for prolonged observation