Michael Portuesi
Recently, I spotted an ad in Sky and Telescope magazine for binoculars with built-in nebula filters from Apogee, Inc. They are available in several sizes, from 7x50 through to giant 20x100 sizes. I wanted something a little bigger than the 7x50 Celestron binos I've had for years, so I lured myself into purchasing the 12x60 pair. The cost was $89.95, plus $11 shipping, an incredibly good deal compared with the $180 I spent on my 7x50's several years ago. I figured they cost so little, compared to other astronomy equipment at least, I couldn't go wrong by taking a chance.
The binoculars are what you expect of Chinese-built astronomy equipment: good but not exceptional quality, but a great bang for the buck. The mechanism works well, but overall fit and finish is not what you expect from, say, a nice piece of Japanese equipment. Black paint covers the outside, rather than rubberized covering many binos sport nowadays. They still look attractive, but the metal tube means they can be cold to the touch. A view through the objective lens shows metal parts that aren't fully blackened, as well as surfaces covered with some substance (adhesive? lubricant?) And the little cover for the tripod mounting bracket hole won't screw on tightly.
They literally stank — stank as in smell — when I pulled them from the box. It was a combination of the rubber, lubricants and adhesives they use in the manufacture of the binoculars. Most of the smell wore off a day later, but even after two weeks a smelly residue remains.
You get a fairly nice nylon carry case with a velcro closure, a cleaning cloth, and a tripod mounting bracket that fits my Vanguard photo tripod nicely. They also include a rather cheesy carry strap that I don't trust. You also get lens caps for the objective lenses, as well as the ocular lenses. But the ocular lens cap fits loosely, and falls off quite frequently.
The binoculars are quite light for their size, and not too tiring to hold, though I have been using them almost exclusively on the tripod.
The real attraction of these binoculars are the built-in nebula filters to increase contrast when viewing emission nebulae, plantary nebulae, and supernova remnants. Several notable nebulae, such as the Veil Nebula in Cygnus, the North America Nebula in Cygnus, and the Rosette Nebula in Monoceros, are larger than the typical field of view offered by a telescope. Binoculars allow you to take in the entire nebula in one go, and the lower magnification compacts the nebula into a smaller view. This can make an easier view through binos than through a telescope.
The thumbwheel for the left-side nebula filter is down and
to the left of the left ocular.
Two thumbwheels, one underneath each ocular, slide the filters into view. They work very smoothly, and are reminiscent of the optical instruments your optometrist uses during an eye exam. They even make a similar noise when you click them in and out of view.
The daylight view through the filters is a very medium-green. I compared the built-in filters with my telescopic nebula filters: an Orion Skyglow broadband, and Lumicon UHC and O-III. My nebula filters all pass more blue than the filter built-in to the binoculars. Actually, the view through the filter in the binocular looks closest to the #58 green planetary filter I have. That led me to believe it may not be a true nebula filter at all. But after looking thorugh the objective end of the binoculars, I've caught red-purple reflections off the filter, indicating the presence of dielectric coatings and a true nebula filter.
I tried the filters with the Moon, to cut down on its glare. But I found the Moon's light caused several internal reflections when the filters are in place. This should not be a problem when using the filters for deep-sky nebula observing.
My first real test of the filters came at an observing session June 5, 2004 at Montebello Open Space Preserve in the San Francisco Bay Area. This site is close to suburban Silicon Valley, with a good amount of light pollution to the north and east. We first viewed the Veil Nebula in Cygnus, through a great deal of skyglow. The light pollution made the nebula difficult to observe with or without the filter; it was subtle and very difficult at best to detect. But I and other observers agreed the nebula filter did make the Veil a smidgen more noticeable.
We had much better results with the Lagoon Nebula in Sagittarius, in a darker region of sky. Here, the filters definitely exposed more of the nebula when used. With no filter, the cluster contained within the Lagoon dominates, and nebulosity is present, but not extensive. With filters, the extent of the nebula surrounding the star cluster is extended and easier to view. Stars become fuzzier and harder to see with the nebula filters in place, but that's true of nebula filters in general.
The pair arrived in good collimation, and they have collimation screws at the front and back of the prism section. The collimation screws seem covered with a dab of wax or some other substance to keep you from getting at them.
A center focus knob adjusts both oculars, with an independent focus on the right ocular. Eye relief on the oculars is very good; you don't have to press your eyes up against the lenses in order to take in the full view.
The optics have blue-green coatings. The claimed field of view for these 12x60's is 5.7 degrees, but in reality, I think it may be a little smaller, comparing the bino field versus charts generated with SkyTools software.
The optics are good but not great; but they are great for the price. They give very nice views of daytime objects. I have been using them the past several nights for the binocular portion of the Astronomical League Lunar Club observing program. My view of the Moon shows a little false color (red/blue fringing) around the edges, with more color visible with objects placed at the edge of the field of view. This is very comparable to a ShortTube-80 or other Chinese-made achromatic telescopes. Still, the view of the Moon I have been enjoying the past few nights is very crisp. Craters show nice, delineated rim edges and are easy to pick out against the Moon's surface.
There is some amount of fuzziness in objects at the extreme edges of the field, and some flaring is noticeable when viewing bright stars. It is important that you adjust the focus properly on both eyepieces. I saw a good amount of false color on bright objects like Jupiter, before I got the right-side eyepiece focused properly. With a proper focus, the color is much reduced, and while still noticeable, not annoying. Jupiter's moons were nice dots, easy to pick out, and easy to tell relative brightness.
I have observed Comets C/2001 Q4 (NEAT) and C/2002 Q7 (LINEAR) with these binoculars, as well as some of the brighter Messier objects - open and globular clusters, nebulae, and galaxies. Views are bright and contrasty, and compare well with telescopic views through refractors. Overall, views have been very pleasing, and well worth the price. On the other hand, I was not seeking optical perfection when I ordered these binoculars, and those demanding high performance should look elsewhere.
I'm pleased with my purchase. I was looking for a good deal on a pair of cheap but useful binoculars, and I'm having a blast observing with them for not a lot of money. I would recommend these binoculars as a good second pair, or as an inexpensive starter for a beginning astronomer. Other observers and I agreed the built-in filter concept is worthwhile, and that some manufacturer should run with the idea and build a high-end pair of binos with filters.
Apogee, Inc.
P.O. Box 136
Union, IL 60180-0136
(815) 568-2880
www.apogeeinc.com
