Swarovski EL 8.5x42 Swarovision review
9-3-2015, last revision 15-12-2020

Test sample´s serial number K850344020, kindly provided by Swarovski Austria. Review period started 26-1-2015 and ended about 1 year later.
Introduction
The Swarovision was the first true roof prism alpha bin I ever got and I was initially very impressed with it. But after comparing it with all other alpha 8x42s in 2015 I developped a taste for more classic, curved field designs.
A decisive moment was when I first noted the difference in the rendering of space between the Swarovision and the Leica Ultravid, a stork about 80 meters away in a meadow. With the Ultravid, I could clearly see the bird´s position in its surroundings, whereas with the Swarovision everything was pushed into one plane and ended up looking almost 2D. This is even more prominent in close observations, where a classic design will show you the exact position of each branch of the bush your bird sits on, where the Swarovision or Nikon EDG will strongly und unnaturally compress space.
Five years later, I have developped a strong aversion against flat field designs, mainly because of this. Both in binoculars and photography lenses.
The Swarovision surely impresses, but I found it stale in the end and decided not to keep it.
What are the unique qualities of the Swarovision in a nutshell?
Characteristics
The Swarovision offers extreme ease of view, which in two respects already makes it unique among 8x42s: Firstly, you can scan the whole image by eye movement instead of moving the point of interest into the middle of the frame, without any blackouts happening. Secondly, you can basically focus from infinity to close without changing your interpupillary distance and still have a comfortable view. Even beginners and lazy people can easily use this glass.
Contrary to their older models and their SLC line, Swarovski has not boosted the contrast much by introducing a slight colour cast (yellow green). The Swarovision has pretty neutral colours, but is also at a disadvantage compared with other glasses who boost contrast (everything in the Zeiss line, Swaro SLC, and, although less than those two, Ultravids).
Regarding edge performance, there is a strong dip in contrast at about 75% of the field, then a steep rise again (ironically refered to by some as the "Absam ring" after the home town of Swarovski). This looks a bit artificial.
Worse, the uneven distortion pattern of the Swarovision introduces a lot of warping when panning and tilting the glass which more sensitive users may loathe as it might cause a kind of seasickness effect.
Suppression of flare is not a strong point of the Swarovision, which might have to do with the extreme emphasis on ease of view Swarovski designs are famous for. I do not know why that is, but I feel that tight internal baffling generally reduces ease of view.

Mechanical performance
The body is very solid with perfect friction of the hinges. Definitely high quality finish everywhere. The focusing is still not as velvety smooth as I would like it to have, but the best of the Swarovskis I had in my hand, the friction is adequate, not too light. The focusing throw is very long, the finger has to snap back once to focus from 7 to 150 meters. For me that is not an issue, and I really love to pull focus on a big bird flying slowly towards me. Eyecups can be locked in three different positions.
Handling is excellent, these binos fit perfectly in my hands, with good balance, and the texture of the rubber is good and feels durable.
The tripod adapter is really special and cleverly designed. The adapter is short and very close to the bottom of the body and allows you to handle the glass handheld even with the adapter on. It should work on many other roofs, too. As my tripod has an easy leveling feature this is my favourite adapter system as it is so compact. On most tripods the leveling feature of the SLC adapter type would be more convenient though, but that adapter is bulky and needs to be detached for handheld use.
I admit I´m fond of good industrial design. This one is a real beauty. If it has not found its way into the Museum of Modern Art collection yet it probably will.
Baffles? What baffles?
Optical performance
Sharpness and contrast transfer
is awesome. First binos that comes into the league of my trusted Swarovski Habicht 8x30W in that respect. Images have an almost surreal chrystal clarity. The impression of biting sharpness comes from a very high contrast at coarse edges. But the contrast transfer must be unusually high even at the resolution limit of the eye, and that is what makes the images so rich, vibrant and clear. And it stays like this even at open pupil. Amazing shapes and wonderful textures.
From the center to about 60% of the image radius contrast transfer is extremely high, then slightly and sort of secretively decreases a bit in the outer zone to have a quite steep rise again so that the last 20% of the field towards the edge are very sharp and contrasty again. This field flattening is much better implemented than in the 8x32 Swarovision (note: this model may have had a slight optical modification since I tested it). The smaller sibling has an extremely steep drop and then increase of contrast transfer at about 80% of the radius, creating a ring of unsharpness which at the same time marks the transition from pleasant slight pincushion distortion to the lack of it (or maybe to a more complex distortion). In the 8.5x42 we have a really much more user friendly flat field, and this was a total surprise for me.
No matter if one prefers flat or classic field, there is no way to get such a truly spectacular performance in contrast transfer and sharpness without very low manufacturing tolerances and strict quality control.
Transmission and colour reproduction
The Swarovision shows the finest colour subtleties very naturally. It definitely has slightly colder images than most other binoculars. Transmission measurements by Gijs van Ginkel show the Swarovision allows for a strong, unhindered transmission of the blue spectrum but cuts away some red. That would give it just a hint of contrast boost by a tiny skew towards green.
The SLC cuts both red and blue quite a bit, and Swarovski claims an "extremely high-contrast image" whereas the Swarovision is "chrystal clear". Indeed the boosted contrast in the SLC, which also shows a very high perceived brightness, is not found like this in the Swarovision.

Ease of view
is exemplary thanks to a perfect alignment and probably a very advanced optical construction of the oculars with a well corrected exit pupil. At closed pupils these binos are very tolerant to where I put my eyes. I feel I can provoke blackouts easier in the SLC when missing the best position.
Distortion and rolling globe
I will check for distortion pattern with the brickwall of my trust soon. Using cupboards and drawers as test object it seems that there is very slight pincushion in the biggest part of the field which decreases towards the periphery. Surprisingly I don´t have serious issues with rolling globe, very unlike as with the 8x32 Swarovision which made me often very nervous when doing fast pans or tilts. Maybe the 8x32 Swarovision with its slightly wider field of view always had worse rolling globe due to more emphasis on small volume. Anyway, in the 8.5x42 I was not bothered by rolling globe, the uneven distortion is perfectly acceptable for me.
Field of view
is wide (7.6°, 133m/1000m) and flat.
As discussed above, the flat field implementation to my eyes is much better than in the 8x32 Swarovision, with a much smoother transitions from center to outer zone to edge. The flat field is a real wow effect for the most inexperienced user even, and it is well usable with open pupil, although details in the outer zone become a bit less well defined then.
Close focus
is stunning, with perfect optical performance. I was marvelling for a quarter of an hour or so at details 1.5m away. Putting the binos down I had a strong double image for a couple of minutes. Of course squinting is unavoidable at the close focus even in the best roof binoculars. So this is one spec that really does not need to be pushed further. But I look really forward to do more macro watching once butterflies and lizards are back.
Flare
The only issue I have with this glass is that with the sun in front, there can be some veiling glare making shadows grey and lowering contrast, and some crescent flare at the peripheries. My Habicht 8x30 and the Swarovision 8x32 are much worse though. The 8x42 SLC may have a bit less veiling glare, but suffers much more from crescent flare. With the sun at the back or on a dull day or in twilight the Swarovision´s image is surprisingly free from flare, it is very clean and "quiet", whereas the SLC´s image is nervous in comparison with frequent, if only weak crescent flares in the periphery. To sum it up, it´s mainly veiling glare in the Swarovision - sunshades would often help when watching against a high sun - but the flashing crescent flares at the periphery from for example bright skies are very well controlled. I enjoy that very much, it´s an important part of the image quality.
Chromatic aberrations
are very well controled, this is state-of-the-art in my experience, although you will find some in high contrast situations and towards the periphery. Both Habicht and SLC are much worse.
Stars and street lanterns
The night sky looks spectacular with the Swarovision, I saw very little coma. Panning across our bright LED street lantern there was a bit of white flare and a couple of green ghosts.

Compared to other binoculars
Vs the SLC 8x42 WB

What the SLC does better:
- Much deeper, more natural rendering of space, the Swarovisions Achilles heel.
- Higher perceived contrast and brightness due to boosted contrast/skewed transmission curve.
- Very comfortable panning behaviour, unlike the strong warping of the Swarovision images.

Conclusion
No doubt: a great binocular, but with serious flaws. Make sure you can live with flat and warping images.
The SLC is my favourite 8x42 and comes at a fraction of the price. Hunters especially should like the optimized contrast of the SLC. Do not mistake it for an inferior glass because it costs a lot less.
