The Burgess Binoviwer
Didn't quite know what to expect. I mean sure, we know that the Mainland Chinese factories have been able to turn out some decent gear for amazing prices over the last few years. But binoviewers? In the past, the combination of "cheap" and "binoviewer" has meant "eyestrain" and "waste of time" and, generally _YUCK_.
Anyway, a look at the Anacortes website revealed the specs on this thing:
Binoviewer w/Bak4 Prisms with 18 mm Clear Aperture and Broadband Coatings. Dual Individual Helical Focusers. Threaded for Filters.
Luckily, we're undergoing one of our infrequent spells of clear, cool weather down here in Possum Swamp, so I was able to get the Burgess out to my club's suburban Pine Lank Observatory site for some deep sky testing last night. While this location is far from perfect light-pollution-wise, it's good enough. The Nexstar 11, the scope I'd use for the test, was capable of revealing detail in M76 at this location, for example.
In addition to the Nexstar 11, my setup was as follows:
Peterson "EyeOpener" 2 inch visual back that allows me to insert a 2 inch diagonal directly into the back of the C11, allowing for a more stable installation of heavy equipment like binoviewers than you get with a 2 inch adapter attached to an SCT's standard/small rear port.
Denkmeier SkySweeper. I use this f/5 reducer almost exclusively now. It's easier to use and more versatile than a Meade or Celestron reducer corrector. I screwed the SS onto a 1.25" - 2" adapter that I then inserted the Burgess into. The Burgess is a 1.25" device like most current binoviewers.
2" Intes enhanced diagonal.
I used a Denkmeier Standard for comparison purposes. The model I have has the self-centering eyepiece holders, but no helical focusers.
Handson Optics' GTO plossl sets. Yeah, I know they ain't Cadillacs, but they are sharp, very sharp. They were also attractively priced when I was first getting into binoviewing, not too long ago.
What first? Can't let M13 slide away without one more look. I got the NS11 aligned and sent it that way. I started out with the Denks. MAN...I'm still impressed by this thing. It's so comfortable to use, and just works so darned well, delivering beautiful views of the deep sky in addition to the Moon and planets. With the 25 mm plossls, the field stop was sharp, and the field was well-illuminated to the edge. Many, many tiny stars twinkling out of the light pollution and thick air down toward the horizon.
OK...moment of truth. It was time to give the Burgess its chance. What to expect? I didn't know. Or, rather, I did realize that it wasn't very realistic to expect the Burgess to keep up with the Denk. The Denk Standard's price with no accessories is now an amazingly low $499.00, but that's still more than twice the price of the Burgess at $199.00.
"OK steady as she goes...25 mm plossls in place...Denk safe on the observing table--man, this dew is HEAVY--what will it be? A dim microscope bino-head disaster?"
Nope. Not at all. YEAH, BABY! The stars of M13 looked as good in the Burgess, frankly, as they did in the Denkmeier. There was no detail that I could see in the Denk that I couldn't see in the Burgess. These relatively poor skies are probably not the ultimate test, but I was impressed by the brightness of the Burgess' images. So the view in the Burgess binoviewer was just as good as it was in the Denks? Well, NO...
The smaller clear aperture of the Burgess produced significant vignetting with 25 mm plossls. The field stop was fuzzy, and the field noticeably smaller. Was this fatal for the Burgess? No, not really. I noticed it most when I switched back to the Denkmeier. When I didn't worry about it and just concentrated on enjoying the sky with the Burgess, I really didn't notice it. With a StarSweeper in place, the field is more than generous enough to make this device useable on the deep sky with an f/10 SCT.
To use a time-honored (or worn) automotive comparison cliché, using the Denkmeier was like sitting behind the wheel of a BMW. "Turning the key," on the Denk and roaring off into the darkness, it just seemed so solid and POWERFUL. In contrast, the Burgess was more like the family's Ford Taurus. It started and ran well. But without that precision feel. On the other hand, one can enjoy the passing scenery just as much from the window of a proletarian Ford as you can looking out of a classy BMW.
How about shorter focal length eyepieces? The vignetting disappears at about 20 mm, and 9 mm plossls in concert with the StarSweeper provided a good view and helped suppress the bright sky background at my light-polluted site. M15 was particularly nice, with its blazing core and hordes of tiny stars. As for the operation of the Burgess, it was--in MOST ways a snap. There's plenty of interpupillary adjustment available, and I had no trouble merging images MOST of the time. The helical focuser on each eyepiece barrel worked well and smoothly.
That "MOST" in the above paragraph relates to the Achilles' heel mentioned earlier. When you're using short-barreled, short focal length eyepieces, tightening the eyepieces down using the Burgess' setscrews tends to cock the oculars in the eyepiece holders, moving the image in the field, and UNMERGING the images in the binoviewer. Like the vignetting issue, however, I found this not to be a fatal problem for the Burgess. I did NOT like it, but was able to work around it easily enough. The setscrews on the Burgess are equipped with small plastic washers, and these help you to gently fine tune the pressure on each eyepiece. However, since I had the NS11 setup in alt-AZ mode, meaning the binoviewer would not assume any odd positions with respect to the ground no matter where I pointed the scope, the expedient I used most often was just to leave the setscrews loose, maybe applying just a small amount of pressure. In this--or any alt-AZ scope--there won't be any danger of the eyepieces falling out, no matter how the scope is moved.
Again, I don't think this--the setscrews--is a good solution for any binoviewer, and if it might be possible to come up with something else without increasing the price of this unit, I'd URGE Burgess to do it. But, again, it was not a show-stopper. This image-merging problem brought on by the setscrews is most evident with higher power shorter barreled eyepieces. With the 25s, I could crank down the setscrews and not notice much of a problem.
Once I had a feel for the setscrew situation, I just sat down at the scope and ENJOYED the Burgess! M2? Scrumptious. M30? Weird and beautiful. NGC 1023? That's a galaxy that looks good in a binoviewer! And all this goodness available at less than 200 bucks? Man, oh, man! No, this unit is NOT perfect. I had to downcheck it due to the setscrews, and--a more minor issue--the somewhat constricted field, but I never thought I'd see this kind of quality in a binoviewer for this price. NEVER. I'll be honest, when Bill B. announced he'd be offering a bino in the 200 buck range, I was very skeptical. Not any more.
Next step? The Burgess, like any binoviewer, cries to be taken for a spin on the Moon and planets. Well, the Moon will be coming back into the sky, and Saturn's rising early enough to be doable for me now...
And then many cloudy nights intervened…
Herb and Ray kindly offered to let me hold onto the Burgess Binoviewer (“BB”) until the end of the month so I could give it a try on the Moon and Saturn, at least. Yes, I know Jupiter and Venus are in the morning sky now, in November 2004, but my current commute means that during the week I have to hit the ground running at oh-dark-thirty (4:30 am for the non-military folk amongst you), and I really don’t feel much like setting up a scope early enough to catch Jupe before I have to hit the road. Weekends? You’re kidding, right? On weekends I SLEEP! So Saturn and Luna were it, and I finally got some relief from clouds on Thanksgiving night.
Certainly this was not an optimum evening to be playin’ with the Burgess; a front had just passed through, clearing out those bad ol’ clouds, but leaving decidedly poor seeing in its wake. I endeavored to persevere anyway—clouds were predicted to roll right in again behind the clear weather, so it’d be Turkey Day Night or nothing. While waiting for Saturn to appear, I turned the Nexstar 11 to the Moon. A 14 day old Moon isn’t normally a very interesting subject, but it was all I had at the moment Solar-System wise, and in the past I’ve been amazed at how much a binoviewer can bring out in a Full or nearly so Moon.
One thing I noticed immediately was that running the C11 at f/10 reduced the vignetting that had been apparent in my 25mm plossls at f/5. Oh, it was still there in the form of a fuzzy field stop, and an obvious darkening a little farther in toward the center of the field than that, but it was certainly not overly objectionable on the Moon. This was a rather pleasant surprise, as I’d expected the Moon, bright as it is, to provide a very messy, distracting field edge with the 25s. The brightness of Diana also gave me a chance to evaluate the light-throughput of each eyepiece. In general, this seemed quite good. I did, however, seem to detect that that left eyepiece’s image was just slightly dimmer than that of the right. I’m not ready to say this is characteristic of this binoviewer, though, since my (middle-aged) eyes ain’t what they used to be. Certainly, the image of the Moon in the Burgess was very good, with Tycho, for example, offering a wealth of detail, both within its walls and in its ray system.
When it comes to optical quality, nothing is a more challenging target than a planet, and it’s hard to imagine a more demanding planet than Saturn. It offers plenty of detail in its ring system and on its disk, but this detail is of very low contrast. Unlike Jupiter, it’s also a hard-edged little bugger, and any problems with image merging are painfully apparent. When Saturn had achieved 30 degrees of altitude I sent the Nexstar that way and took a peek. Whoops! I was definitely seeing two—or at least one-and-a-half--Saturns.
After the experience of my initial observing run with the BB, I knew what the problem was. Those blasted eyepiece holder setscrews. I backed ‘em off, and the two Saturns snapped into one nicely merged planet. Since not everyone will want to (or be able to) leave the eyepiece setscrews loose, I did a little further experimentation. I found that I could turn one of the diopter focusers (didn’t matter which one) and at some point the images would merge even with the setscrews cranked down hard. Usually the images would merge when said setscrews were pointed at about the same angle. Luckily, I found that I never had to turn a diopter focuser so much that the image in that eyepiece was obviously out of focus compared to the other one. This is at least a slightly more elegant solution to the “set screw problem” than just leaving them loose.
How did Saturn look when everything was merged and focused up? Very nice, given the fairly poor seeing. In the 25 and 12 plossls, the ringed wonder was as sharp as I could expect given the unsteady condition of the upper atmosphere. The most telling thing? As with any good binoviewer, I could definitely see more with two eyes than I could with one, even when I went to decidedly upscale Panoptic and Nagler eyepieces in “Cyclops mode.” As is always the case when I use a binoviewer on Solar System objects, I was struck by the pseudo 3D effect. The distance between your eyes does not give you nearly enough of a “baseline” to see any celestial object in three dimensions. But your brain doesn’t know that. As far as it’s concerned, if you’re using two eyes, you must be seeing in 3D, and it arranges things to suit this “reality.” Saturn and its brace of Moons showed striking (if false) depth in the Burgess, with bright Titan in the foreground, the planet in the mid-ground and, and three dimmer members of Saturn’s retinue lurking in the background.
Final thoughts? I feel the same way as I did when I finished my deep sky runs with the Burgess: it’s a very good value for the money, but the prospective purchaser should be aware that it’s certainly not perfect. I found the setscrews and the concomitant image-merging problem quite annoying. And there are those smallish prisms and the resulting rather small clear aperture, which places a limit on this unit’s ability to produce wide field vistas, something that reduces the Burgess’ impact when used for deep space observing.
On the other hand, for $199.00 you’re getting a binoviewer that can provide clear, sharp and, with a little fiddling, well-merged images. The main drawback of the BB, the vignetting, will not be much of a problem for planetary observers, and the Solar System is the place where binoviewers really strut their stuff anyway. But the real value of the Burgess? It’s a godsend for those folks considering binoviewing but unsure whether they’ll like it enough or use a binoviewer enough to warrant paying for a top-of-the-line unit. If nothing else, the Burgess provides these folks with a painless entry to the art of two eyed observing. The Burgess is also good enough that there will be a demand for it on the used market if the original owner decides, like many of us have, that bino- observing is such a wonderful experience that it’s time to go the BMW-Cadillac-Rolls route.
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