A Work Commenced February 11 2025
Product: Oberwerk ED Ultra 15 x 56
Country of Manufacture: China
Clear Aperture: 56mm(measured)
Exit Pupil: 3.73mm
Field of View: 88m@1000m(4.7 angular degrees)
Close Focus: 15m
Focuser Configuration: Individual Focus(IF)
Coatings: Fully Broadband Multicoated
ED glass: Yes(FK-61)
Field Flatteners: Yes
Prism Type: BaK
Waterproof: Yes
Nitrogen Purged: Yes
Weight: 1.48 kilos
Accessories: Padded soft case, mounting bracket, rain guard, objective caps, neoprene neck strap, microfibre lens cloth, test & warranty certificate.
Warranty: 5 Years
Price(UK) £549.95
When it comes to large, high-power binoculars, Oberwerk is a name that trips off the tongue. For a quarter of a century, its founder, Kevin Busarow has been servicing the astronomical community with a swathe of innovative products that deliver excellent value for money. One of the most admirable attributes of Oberwerk is their commitment to developing their optical wares as new technologies become available.
The original Oberwerk Ultra models had good achromatic optics, full sized prisms and housed in a robust, weatherproof chassis. Fast forward a decade and the same series now possesses extra-low dispersion objectives and field-flattening optics with significantly improved eye relief for eyeglass wearers.
Another point of significance is Oberwerk’s commitment to the Porro I prism design, which has several advantages over larger aperture roof prism models. For one thing, because the eyepieces of roof models are aligned with their objectives, their minimum IPD becomes progressively larger as the aperture exceeds 50mm. A 70mm roof would probably have an IPD near 70mm meaning that many users, yours truly included, could not bring the barrels close enough together to merge the images. That’s not an issue for Porro I prism designs, the objectives of which have large offsets to allow the majority of human faces to engage with them.
In addition, larger roof prism binoculars of high optical quality are more expensive than a well executed Porro I model of equal quality.
Having tested hundreds of binocular models – both roof and Porro – particularly under the stars- I have cultivated a strong preference for Porro prism models in larger apertures. Stars present as tinier pinpoints without the commonly seen diffraction spikes all too often witnessed in many roof prism models.
So when Oberwerk launched their new ED Ultra Series of Porro I system binoculars, I became particularly intrigued by one model: the 15 x 56, for reasons I shall elaborate on later. What follows is a detailed review of this instrument, based on several weeks experience during daylight hours but also after dark.
A Closer Look at the Oberwerk ED Ultra 15 x 56
The Oberwerk ED Ultra is an exceptionally handsome and beefy binocular, tipping the scales at 1.48kg. The tough magnesium alloy chassis is overlaid by an attractive grey textured rubber armouring, with black and red accents placed at the sides of the barrels.
The eyepieces are focused individually and are clearly marked with their +\- 5 dioptre compensations. They rotate smoothly and accurately, maintaining their positions well. The eyecups are fashioned from black rubber and have plenty of useable eye relief. Folded down, I was able to easily engage with the entire field using spectacles. Indeed I later found that while I do not use eyeglasses while looking through binoculars, I strongly preferred using the 15 x 56 with the eyecups folded down, as shown below:
While it is certainly true that Porro prism binoculars are more prone to being whacked out of alignment, these new Ultra ED models possess a 3-point floating plate housing for the full-size BaK 4 prisms at the heart of the instruments. That’s very reassuring, as this will almost certainly mean these models will hold precise collimation indefinitely.
Both the objective and eyepiece lenses exude attractive pink coloured anti-reflection coatings very similar in fact to their excellent SE series instruments.
Another neat feature of the 15 x 56 ED Ultra is the easy to read interpupillary distance measure on the bridge which is of great assistance in maintaining the optimal spacing of the eyepieces with one’s eyes.
The central hinge is fashioned from strong metal, rendering adjustments very smooth and precise. Once set, it’s sufficiently rigid to hold its position precisely.
Mounting Options:
The interesting thing about a 15 x 56 configuration is that it’s neither lightweight or overly heavy. That means it can be enjoyed handheld or mounted. I used a simple, Rick Young harness to transport the instrument while exploding the rural landscape near my home. A binocular harness distributes the weight of the binoculars more evenly across your body, reducing strain on your arms and hands. This allows for a more stable hold, especially during prolonged use.
In addition, there’s less chance for hand tremors or involuntary movements to affect what you’re viewing. This is particularly beneficial for observing distant or moving objects. What’s more, using a harness can encourage better posture, as it allows the user to maintain a more relaxed position while viewing. Proper posture can also help in reducing fatigue, which in turn helps maintain steady vision. All in all, these ergonomic features collectively help stabilise viewing through the Oberwerk ED Ultra 15 x 56.
Another option is to mount the binocular on a sturdy photographic tripod via the supplied bracket. While this is a good way to obtain steady views for terrestrial viewing, I found it rather inconvenient for astronomical observing, preferring instead a sturdy monopod. I elected to use Oberwerk’s excellent Series 2000 monopod with its trigger grip head for easy adjusting both in altitude and azimuth.
To be Continued…….