did a quick eval of the hype zoom this saturday, again at the local hawk watch, using my at66 'fractor, and for a "control" of sorts, a nikon 82ed. my celestron c-fed, which i had to return due to a malfunctioning power dial, has not returned from their service department, so i will not be able to try the baader on that spotter for awhile yet.
first impresssions out of the box were very positive. quite a robust build, and extremely smooth and precise rotation of the power collar. love dem click stops! i have no other experience with variable power EP's, save for the celestron one that didnt work, so really dont have a base of comparison from a mechanical standpoint. but i wouldnt doubt that this would be about as good as it could get. i do note the hype sits very far down on the rim of both the 45-degree erect-image and 90-degree star diagonal, to the point where it interferes with the tightening of the set screw. not really a problem, as i just pulled the EP a hair off the thumb screw and all was well.
i was able to verify, as i have read in the past, and as mentioned by henry, that the 45 degree erect image diagonal does degrade the image substantially, esp above about 30-power. below that, i dont think the scale was large enough to really tell too much diff. at 50X though, max power for the baader on the at66, there was a distinct murkiness and loss of detail, as well as enhanced CA comparing the two accessories. numbers on a power transformer were barely distinguishable as numbers in the erect image diagonal, but could be clearly made out in the dielectric-mirror unit (albeit backwards!). maybe oneday someone will make one of these (for a reasonable price...) capable of holding onto 75-100X? i for one would be willing to spring for say, $100 or so. the baader top-shelf unit with input and output couplings would tip the scales at nearer to $300, i think, and that's a substantial outlay. also, a 90-degree star diagonal is not as neck-friendly to me as the 45-degree bend of the prism. plus the "think right? move left!" handling of the scope is a bit offputting, although i am sure i could get used to it. back to the ocular: the AFOV is somewhat restrictive at the 24mm setting, but as others have remarked, expands out rapidly once you hit the 21 or 20mm mark. eyerelief might be a problem for some with large, bulky frames. i tend to remove my glasses when using a scope so this wasnt a huge issue for me.
fair numbers of olive-sided flycatchers are beginning their neotropical trek southwards, tend to perch still for long periods at the tops of bare branches, and make a decent target for testing resolution performance, it seems, though of course with results not as repeatable or technical as a chart. the "olive sides" contain and are in part composed of long blurry, fat steaks running the lenght of the flanks of the birds. i was interested in how well the zoom, at max power especially, would render this detail. the nikon was fitted with the 50X fixed power ocular, an MC model i think (it has a rotating rigid eyecup). i have always considered the nikon fixed power oculars some of the best i have looked thru.
the birds were perched at several hundreds of feet distant, so that at 50X they were still fairly small in the image. fortunately, the early morning air was still, and the scene was lit by direct sunlight.
what i found, on the resolution of fine detail part, was to my eye the two were very, very close. at times i felt the nikon a bit superior at delineating the extent and number of flank streaks, then again after studying them thru the hyperion i wasn't so sure. if there was an advantage in this area to the nikon, it was small. i think this speaks well of the zoom!
there were a couple of areas though, where i did feel the hype suffered by direct, real-time comparison. one is what i would call contrast. at all power settings, particularly the 12 and 8-by stops, the hype's rendition seemed flatter, with a slight, but noticable, almost milky, washed out appearance to the scene . this had the effect of desaturating the colors of sky, branch and leaf in particular, at least when switching to the nikon, whose view was quite three-dimensional, with a cleaner rendering of color and tone. i also did not find the hyperion to be able to keep up with the fixed power ocular in terms of unity of focus across the field, whereas the 50X MC is one of the most uniform of EP's in this regard i have available, even considering some highly regarded astro ones. branches and small twigs, for example, were cleanly in focus from center to edge in the nikon, whereas the hyperion displayed some defocus beginning at, i'd guess, about 60%, maybe a bit more, out from the center.
perhaps it's not entirely fair to expect any zoom to compare point for point with an exemplary fixed-power ocular. i have to say the convienence of just dialing in a closer look is pretty cool, and overall the hyperion is quite an elegant piece of gear, and a good performer optically as well, particularly as regards detail retrieval. it certainly beats toting and switching out EP's on the fly!
regards,
UTC