While best known for their line of giant binoculars, Ohio-based Oberwerk (who used to be called BigBinoculars.com) also offers more modest aperture binoculars that are affordable choices for casual stargazing.
I purchased and tested their 10×50 Deluxe, a traditional Porro prism binocular that sells for $190, putting it in the under-$200 price class popular with amateur astronomers shopping for binoculars.
OPTICAL QUALITY
The Oberwerk Deluxe’s eyepieces provide an apparent field of view of 64° which, in a 10-power binocular, translates into an actual field of 6.4° (or so it is marked on the binocular). However, the product’s web page lists the actual field as being 6.5°. I found the lesser figure to be more accurate, though the difference is minor.
At night, the Oberwerk’s field appeared slightly darkened at the edge. This vignetting made the field stop less distinct, contributing to the impression that the field was a little narrower than it actually was, especially in A-B tests with the Nikon Action Extreme 10×50 (described below).
In the Oberwerk, stars were sharp and pinpoint on-axis, a sharpness maintained across the central 50 percent of the field. Star images started to bloat with aberrations at that halfway point and became noticeably distorted at the edge.
Eye relief was very good. It is given as 18mm, which is from the outer surface of the eye lens. Measured from the top of the retracted eyecup, however, the practical eye relief is closer to 15mm, which is still long enough for comfortable use with eyeglasses and seeing the entire field.
To achieve sharpest focus with both eyepieces without eyeglasses on, I had to turn the right eyepiece diopter as far to the + side as it would go, as I show above. Most binoculars I’ve tested have had plenty of diopter adjustment to accommodate my eyes, with room to spare. The Oberwerk had just enough, and my eyes are not that dissimilar. If your eyes are very different in focus, you might have to use these binoculars with your glasses on.
Views were as bright as in other 50mm binoculars I compared the Oberwerk to, and limiting magnitude just as good. The aperture was not stopped down as it is in some binoculars. I did not see any issues with flaring or ghost images when looking at the Moon or other bright light sources.
MECHANICAL DESIGN
The main trait of note with the Deluxe 10x50s is their bulk and weight. This is a large, wide binocular weighing 1,173 grams (2.6 lbs), on the big and heavy end of the scale for 10x50s. That can make them hard to hand hold for any length of time.
With my smaller hands, I found the central focus wheel difficult to reach while holding them, even without gloves on, as the focus wheel lies about 9 cm (3.5 inches) from the side of the barrel.
However, people with large hands and good arm strength often prefer a large, hefty binocular for the better grip and more solid feel it provides. The Deluxe will certainly satisfy such a user. Oberwerk’s $290 10×50 Ultra, a marine-style individual-focus model weighing a massive 1,580 grams (3.5 lbs), would be even more of a challenge to hand hold.
The knurled focus wheel on the Deluxe was wide, and its textured rubber surface offered a good grip. It was a little stiff to turn, though that can be an advantage for astronomy where focus can be set to infinity and then left untouched. At sub-freezing temperatures (tested by placing the binoculars in a freezer) the focuser’s grease stiffened so much it made the focuser immovable, but that’s true of most low-cost binoculars.
The twist-up eyecups are a welcome and preferable feature over eyecups that fold up and down, as those can eventually crack and disintegrate. Nor are folding eyecups as convenient to adjust when switching between using or not using eyeglasses.
The two eyepieces are threaded for filters, a unique feature that’s good for astronomy. Keep in mind that while twin nebula filters can reveal faint nebulosity, the filters must be shielded from any stray light that could bounce off their mirror-like surfaces.
Both front and rear lens caps are pliable rubber, good for durability. With the Oberwerk’s method of tethering the front caps, I found they did tend to flop down into my face when the binocular was aimed up.
The Porro prisms are held in place internally with dabs of glue, but that’s also true of most low-cost Porro prism binoculars.
The Oberwerk Deluxe comes with a complete kit, notably including a business card from Oberwerk’s owner Kevin Busarow, an individual inspection card filled out the day my credit card was charged and my binoculars shipped, and a card listing support contacts.
In all, the package provides the positive impression of a small, family-run business working to supply good service and unique, high-value binoculars to the astronomy community.
COMPARED TO …
That said, in testing the Oberwerk Deluxe against my “reference standard” for 10×50 Porro prism binoculars, the Nikon Action Extreme, I preferred the Nikon. They are smaller, making them easier for me to grip and focus and noticeably lighter at 1,016 grams (2.2 lbs.). The Nikon presents a slightly wider apparent field of 65° (giving an actual field of 6.5°). Unlike the Oberwerk, it has a bright, fully-illuminated field right up to its sharply defined field stop. Stars are sharper over a larger 60 percent of the central field and are not quite as aberrated at the very edges.
The Nikon proved to be, in my opinion, the top ranked model of several 7×50 and 10x50mm Porro prism binoculars I tested for my book, The Backyard Astronomer’s Guide, before acquiring the Oberwerks. The Nikon has a retail price of $180.
If you would like better optical quality in an even lighter (868 grams) and more compact 10×50 than either of these two Porros, I recommend roof prism binoculars, though they cost considerably more. The Athlon Midas G2 UHD roof prism binocular that I reviewed here at AstroGearToday is a top recommendation.
However, for users who prefer a large Porro prism binocular, the Oberwerk 10×50 Deluxe will provide very good optical and mechanical quality at an attractive price, from a small U.S.-based company dedicated to serving the astronomy market.
Plus: Wide field of view; good eye relief; click-stop eyecups; eyepieces accept filters
Minus: Large and heavy; slight edge-of-field vignetting; limited diopter adjustment
Price: $189.95
Website: www.oberwerk.com
