Gear Review
SWAROVSKI BTX EYEPIECE MODULE
We test the Swarovski BTX Eyepiece Module out in the field
Ayear ago now, we took a ‘first look’ at Swarovski’s revolutionary BTX binocular spotting scope. As with any new technology, though, you really need to take a longer look to fully evaluate it, so were our first impressions correct? The first thing to point out, of course, is that it’s a binocular eyepiece module rather than a full scope – you can team it up with the 65mm, 85mm and 95mm objective lens modules familiar from Swarovski’s ATX scope range. I’ve been using it with the 95mm module. That does make for quite a hefty package, although if you’ve already been using a traditional scope of 85mm or above, the extra weight isn’t necessarily going to put you off. You do need a decent tripod to get the best from it, though, and a long lens plate (at least) or even a video-style head for the tripod are an advantage in compensating for the inevitably backheavy design. Swarovski produce both, if you do decide you need them. For me, the main advantage conferred by the binocular eyepiece module is comfort of viewing. The eyepieces themselves are the same as on the EL 8x32 binoculars, and looking through two eyepieces, just as you would with a binocular, put far less strain on my eyes than with a traditional single scope. Even marathon sessions of scanning
a gull roost at a local reservoir, or trying to pick out distant Black Terns at another, didn’t bring fatigue, which will make the BTX very popular with seawatchers, as well as reserves, I suspect. The module’s fully adjustable, with a dioptre adjustment on the right eyepiece. It isn’t lockable, however, and annoyingly got shifted once or twice when setting up. You can also change the interpupillary distance to suit your own needs. Add in an adjustable forehead rest, a very useful sighting device (both of them removable) and a tethered rainguard, and you have a very user-friendly bit of kit. In terms of optical performance, the image produced feels a little deeper,
and more three-dimensional, than with the single eyepiece module, the result of both your eyes sending information to the brain, but it is perhaps very slightly dimmer than the ATX equivalent. That impression, though, was only after switching between the two several times – in normal use, you would certainly not have any issues with the brightness. Nevertheless, the image produced is very bright, by most standards, as well as sharp and natural in its colour tone. Finding any sort of chromatic aberration was very difficult, except in the very early stages when I was getting the eyepieces set up correctly. Magnification is a fixed 35x, but as someone who rarely zooms in above that anyway, that was fine for my needs. There is a 1.7x magnification extender available, though, should you decide that you do need that extra reach. Field of view is 32m@1,000m, and given that the image is sharp right to the edges, that feels quite expansive enough. At £2,070, it’s considerably more expensive than the ATX. But you really do need to try it out and see if it suits you – you might decide it’s a must for the sort of birding you do.