I have always enjoyed looking at the sky on a clear night through binoculars. Seeing through individual optics for each eye creates a feeling of being in space. It’s different than looking through a telescope. Aesthetically, I find it much more pleasing.
Most binoculars, unfortunately, just don’t collect enough light for real deep-sky viewing. But what if you could find binoculars big enough to qualify as small telescopes? Wouldn’t that be like having a telescope for each eye?
If you think so, get ready for the Oberwerk BT–127XL–SD apochromatic triplet binoculars.
First impressions
These binoculars have been created with no compromise. The triplet objectives are made with the same glass (both FCD 100 and FK-61) used in expensive refractors and are fully multicoated. The prisms are huge, allowing full coverage from any 1¼” eyepiece. (Yes, you can change out the eyepieces in seconds. More on this later.) The interpupillary distance, which is the distance between human eyes, is adjustable from 57 to 80 millimeters. I’ve had no problems with the binoculars as various people adjusted the BT-127XL-SD to their eye width. The binoculars come with sliding dew shields and metal covers for the objectives. They’re also finished in iridescent Luna Pearl White paint with an anodized trim. Besides being beautiful to look through, they’re also beautiful to look at.
The prisms are set at 45°, the best compromise for viewing objects at both low and high altitudes. I found it useful to have a tripod that has an elevator column so that you can smoothly adjust the eyepiece position for those who are not the same height.
You can purchase the binoculars with a variety of support structures. The classic is a wooden tripod with an elevation bar and swivel that the binoculars bolt to. The more advanced system I used is one of Oberwerk’s heads that sits on a Manfrotto 161MK2B tripod, which has a crank-operated elevator that can raise the binoculars to nearly 9 feet (2.74 meters). It’s a solid little mount that holds the binoculars with no vibration.
Even with two 5-inch triplet objectives and massive prisms, the magnesium alloy construction keeps the weight of these binoculars at just 24 pounds (10.9 kilograms). I have no trouble setting them up by myself.
Every BT-127XL-SD is tested and collimated prior to shipping with optics certified to a magnification of 163x. The binoculars come with a sturdy case with wheels on one end, making transportation to your favorite dark site effortless. Setting up and taking down the entire system takes only a few minutes each. Oberwerk also provides a limited three-year warranty.
Eyes wide open
Let’s talk about the eyepieces and visual experience offered by these 5-inch binoculars, which come with Oberwerk 14mm (46x) 70° apparent field of view eyepieces. You can also buy 22mm (30x) and 7mm (93x) eyepieces to create a versatile set. The company sells each pair for $319.95. The eyepieces lock in place with a thin ring that sits on top of the much deeper focusing ring. You focus each eyepiece individually.
These binoculars crave dark and transparent skies. Trips through Sagittarius and Scorpius under these conditions have to be seen to be believed. Everything looks 3D. When you look with both eyes, brighter objects fool the mind into thinking that they are in front of dimmer detail. The apochromatic objectives are completely color free. I have looked for, but never found, any color fringing. And just as importantly, stars remained mere pinpricks through all of my eyepieces.
The BT-127XL-SD allows you to take a journey through star clouds and galaxies. Indeed, you can see galaxies in these — just as well and just as many as you would with any high-quality 5-inch refractor. You can see all of the Andromeda Galaxy (M31) within the field, bright and floating in the depths of space; I found the offered view unique. Changing eyepieces will certainly change the magnification, but will it provide more detail? It depends on the object really. Remember, each lens is only 5 inches of aperture, so there are limits.
The bottom line, then, is that the point of these binoculars isn’t to see the closest, most detailed view of a celestial object, but rather to see a unique view using both eyes at once. Which brings up an important fact: Using both eyes eliminates eye fatigue. I have spent many years looking through telescopes with apertures as large as 24 inches with only one eye. After a while spent staring at an object, my eye got tired; the more I looked, the less I saw. With both eyes, I can look as long as I want. And in this case, the more you look, the more you see.
Finally, the tripod, mount, and binoculars are made in such a way that they can be transported to almost anywhere on the planet. Think of your most exotic observing location. Hawaii? Chile? Africa? There’s a good chance the BT-127XL-SD can be there with you.
In short, Oberwerk has created something that dreams are made of: binoculars with 5-inch apochromatic objectives in a relatively lightweight, attractive body. Everything about these binoculars reflects fine workmanship. They are compact enough to go just about anywhere you go and allow views that will leave you happy. I recommend the Manfrotto tripod with the elevator column. Everything sets up in just minutes. For the budget-conscious, Oberwerk’s eyepieces, both the pair that come with the binoculars and the ones the company offers for purchase, are an excellent choice. Once you have the BT-127XL-SD set up at a star party, you might find yourself the center of attention. There is something irresistible about large binoculars.
