Whether it’s scanning through flocks of shorebirds along the Yellow Sea looking for a Spoon-billed Sandpiper or searching the barren rocky slopes of the Tibetan Plateau in the hope of glimpsing the elusive Snow Leopard, anyone who has used a telescope for hours on end will testify to the fact that squinting with one eye for any length of time can cause considerable discomfort. Regular breaks to ‘recalibrate’ the eyes and relax the muscles are required, interrupting the concentration and potentially causing the observer to miss what he/she is looking for.
This longstanding problem for regular telescope users now has a solution – the Swarovski BTX. The BTX is a new module for the ATX/STX modular set-up and essentially offers a binocular eyepiece whilst maintaining the single objective lens. Not only do the two (adjustable) eyepieces make for much more comfortable, and balanced, scanning, the addition of the adjustable forehead rest means that the biggest risk of use is falling asleep!
Alongside many prominent birders from around the world, I was privileged to be invited to Swarovski Optik’s headquarters in Tyrol, Austria, in February to be introduced to, and to road-test, the BTX. As Swarovski Optik CEO, Carina Schiestl-Swarovski, and Dale Forbes, Head of Strategic Business Development, unveiled the BTX there were audible gasps around the room, then a spontaneous round of applause. And that was before any of us had even looked through one. It simply looked the business. Minutes later, several BTXs were set up outside and we were soon trying out this masterpiece of engineering in the stunning mountains of Austria.

So, how was it?
My first reaction was that the BTX will revolutionise scanning. Anyone who uses a telescope for prolonged periods, whether its a waterbird surveyor, a tour guide in Ladakh or a sea-watcher at the coast, the BTX will be a God-send. The comfort is striking when compared with a traditional telescope and, additionally, seeing with two eyes certainly adds a good deal to the quality of the viewing. It seemed to me that I was seeing more, and more quickly, when using the BTX compared with the traditional ATX. It’s simply a more pleasurable, and more natural, viewing experience.
Over the following two days we took the new kit to Lake Constance where we scanned the flocks of waterfowl. After only a couple of minutes, adjusting the (removable) forehead rest and getting used to using two eyes, I found the BTX a delight. We enjoyed superb views of a range of waterfowl including Whooper Swan, Greater Scaup, Long-tailed Duck, Common Pochard, Goldeneye, Common Merganser and even a few Red-throated and Black-throated Divers before there were whoops of joy from the Americans when a much-coveted ‘redhead’ Smew flew in and landed in front of us.
Visiting more locations around Lake Constance, we put the BTX through its paces in varying light conditions, paired with different objective lenses and using the new ME 1.7x extender (compatible with the ATX/STX and BTX), all of which displayed the optical quality one would expect from Swarovski. With two representatives from Cornell Lab, Jessie Barry and Chris Wood, we were of course religiously recording our sightings using the eBird APP and were racking up an impressive list including White Stork, Short-toed Treecreeper and Red Kite.
As with many brilliant innovations, it begs the question – why hasn’t the BTX been developed before? Well, the answer is, of course, that similar designs that incorporate a binocular eyepiece with a telescope (usually involving two objective lenses) have been produced before but most are bulky and impractical for use in the field. As the engineers explained to us during our ‘behind the scenes’ tour, technically it’s been a challenging project and this is the first time such a design, with the optical quality and practicality we have come to expect from Swarovski, has been produced for birders.

Are there any downsides? Well, the fixed magnification of 30x (or 35x on the ATX/STX 95) is a limiting factor. Producing a zoom would have, according to the engineers, made the BTX bulkier, heavier and a lot more expensive. And there is a little extra weight. For me, the lack of zoom is a minor limitation – when I use my telescope for scanning I generally prefer a relatively low magnification to maximise field of view and the brightness of the image. And, of course, the modular system means that it’s straightforward to swap the BTX for an ATX zoom eyepiece once the target has been found or, if you prefer to stay with the BTX eyepiece, add the ME 1.7x magnification extender, small enough to easily fit into a pocket. In the context of the whole set-up (telescope and tripod), the extra weight is marginal. In summary, the benefits of the binocular view far outweigh the downsides.
The price tag of Euro 2,490 including 20% VAT is not cheap, reflecting the expertise that has gone into the design and the quality of the manufacturing. For existing ATX/STX users, the BTX will be an attractive addition to expand the performance of, and comfort of using, the modular set-up. I expect it to be popular..
Personally, I know the BTX will make a big difference when I go to Qinghai looking for Snow Leopards or scanning the local reservoir counting the ducks and geese whilst looking for Baer’s Pochards and I can’t wait to get my hands on one!

Swarovski is to be congratulated on an innovative and stylish product that cements their place as the pioneer at the forefront of the optics manufacturing. The BTX will be available from May and interested potential customers should know that, from 30 April until 12 May, this revolutionary scope can be tried out in some of Europe’s best birding areas in the UK, the Netherlands, Germany and Denmark. See here for more details.
Huge thanks to the Swarovski ‘family’ for providing us with wonderful hospitality in Tyrol and for allowing a rare insight ‘behind the scenes’. As well as being at the forefront of their industry, it was heartening to see how much Swarovski Optik invests in corporate and social responsibility, in particular sustainability. Their energy and waste management programmes are hugely impressive meaning that their environmental ‘footprint’ is minimal. Combined with the facilities made available to staff, including a kindergarten for employees’ children, a superb cafeteria and impressive working conditions, it’s clearly a great company that is a model for how a company can not only be at the forefront of their industry but also make a positive contribution to the community. Another reason to choose Swarovski!
A nice review of an exciting addition to the Swarovski line. Binoviewers have been a fairly common method of using both eyes with a telescope for years. Swarovski has taken that approach and integrated it into their scopes. Based on experience using a binoviewer on a small apochromat for birding, I think this should be a big hit.
I think so, too..