On the evening of Saturday, 18 October, 1997, I went to Fremont Peak State Park, near San Juan Bautista, California, with my new Meade 127 ED refractor. I have reviewed the 127 ED at great length in another posting, but I did get to do some observing of more general interest while I was there.
Two observers had new Zeiss bino-viewers, one mounted on a Meade LX200 12-inch Schmidt-Cassegrain, one on an Intes 6-inch f/12 Maksutov. These pricey items have stimulated much discussion among my observing friends of late, and I was anxious to try them out. Between the two telescopes, I looked at the Moon, Jupiter, and Saturn.
I have not had much luck with bino-viewers before, and I am afraid that my experience that evening was similar. The result is personal: I have two problems: First, I often have considerable difficulty fusing the images, even with great care adjusting the interpupillary distance. That's a bit of a surprise, since I use regular binoculars frequently, and have never encountered that difficulty there. Second, I tend to observe without my glasses, and there is a considerable difference in the correction for near-sighteness between my left and right eye, more than in the eyes of any of the bino-viewer owners that I know. In consequence, when I step up to a bino-viewer, I typically find that I can focus the telescope for one eye at most, and the only fix is the long, jiggly, fussy operation of loosening one of the eyepieces in its tube and sliding it back and forth manually, by trial and error, till I hit the right position.
That last problem really reflects a glaring deficiency in contemporary bino-viewer design. Although only Zeiss units were present on October 18, I think that all the current commercial units have the same fault: None of them allow any fine adjustment for different degrees of near-sightedness in the user's eyes. That lack not only makes set-up time-consuming and jiggly, but also means that it is very difficult to share views with friends whose glasses prescriptions are different from yours. I am left with the sense that none of these products -- binoviewers -- are really ready for the market. After all, when was the last time you saw a Zeiss binocular -- or a Tasco binocular, for that matter -- that did not allow some means of varying the focus from one eye to the other. For what these gadgets cost, surely it could not be too much trouble to put a coarse thread on one of the eyepiece holders.
One of the interesting things about being around a state park on a lonely night is the number of thumps and crackles that come out of the underbrush. When that happens, I generally lift my red flashlight to head level and sweep it horizontally, looking for reflections of eyes in the night. Usually there aren't any, but some times there are, and the deep red LED reflections look rather spooky. I was wondering what might be hiding behind a nearby fence post, as I shined my light at it, when the fencepost suddenly opened its low-set eyes and stared at me. Then it lifted its head to rather more than the fencepost's height, and stared some more. "Oh, look at the deer," I said. "Or maybe they're Velociraptors."
With an occultation coming up, and a nearly full Moon high in the sky, we spent a lot of time looking at Lunar features. My new Meade 127 ED shows signs of being a good telescope for that. At 228x, I saw three or four white spots on the floor of Plato, at least three of which were in the positions of craterlets shown in Rukl's atlas, -- no mean feat considering that Plato was so far from the terminator that no shadows were showing there. The pair of large craters, Atlas and Hercules, lay close to the terminator, and the shadows within Atlas clearly revealed its internal rille system, showing in essence all the detail in Rukl.
Users of larger telescopes were experimenting with high magnification. The seeing was not perfectly steady, but it was good enough to warrant going to very high magnification on all telescopes present. The Meade 12-inch LX200 was running at about 800x for a while, and though there was a good deal of chromatic aberration -- perhaps due to the Barlow -- the view showed more detail than at lower magnifications.
The star of the night, however, was the 18-inch Odyssey at nearly 1200x -- with a 4.8 mm Nagler and a 3x Barlow. There were problems using this configuration, as you may imagine. The residual coma of the f/4.5 paraboloid was readily apparent at the edges of the field, something -- again, perhaps the Barlow -- was causing colored fringes that looked like chromatic difference of magnification, and since we could make the Dobson track smoothly at so high a magnification, we were reduced to slewing the telescope slightly, then sitting and watching the Moon glide by, then slewing again. Notwithstanding, the view was magnificent, with enormous amounts of detail; this was far and away the best view of the Moon I have ever had in any telescope. Aperture wins. Wow, does it ever.
When the occultation came, I was watching through the 127 ED at 228x. In an occultation last Spring, Aldebaran had seemed to take a substantial fraction of a second to disappear, but this time the vanish was as near to instantaneous as I could tell. The Moon slowly glided up over the star, and then alpha Tauri winked out.
I did not stay around for the reappearance, I packed and left right away. It had been a short night, but a rather enjoyable one.