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Gear Review: Swarovski SLC 10×42 W B HD

Swarovski SLC 42 HD

When it comes to binoculars the name Swarovski Optik needs no introduction. Along with Leica and Zeiss the Austrian company is pushing the boundaries of optical perfection, and many agree that it currently has a slight edge on its high-end rivals.

In mid 2010 Swarovski introduced a new model to the upper echelons of it’s high-end binocular line up when it gave it’s long-established SLC (Slim, Light Compact) line a comprehensive makeover. They introduced optical enhancements including fluoride HD glass and all new coatings, wide angle eyepieces, a brand new focusing and diopter adjustment mechanism and a magnesium alloy housing.

The result is the Swarovski SLC 42 HD: an outstanding binocular that’s right up there with the very best birding and wildlife optics available on the market today.

Is the Swarovski SLC HD really a classic perfected?

Swarovski’s marketing department hails the new SLC HD as “a classic perfected”, and holding a pair in your hands it’s very hard to argue with that statement. This is a classic single-hinge roof-prism design that looks traditional, yet at the same time manages to be bang-up to date. Everything about it screams cutting edge quality.

I’ve never really got on with the open-hinged design of the flagship ELs (now copied by a host of other manufacturers). Optically they’re superb, but the form factor made them feel odd. I guess I’d get used to it after using them for a while… but with the SLCs there’s no need to get used to anything… they just feel right. They are an incredibly well balanced, compact piece of kit, and a joy to use. They’re not the lightest pair of bins you’ll ever pick up – even with the new lightweight magnesium alloy housing they feel pretty hefty – but because they’re so well balanced they’re not uncomfortable either to carry or to hold to your eyes for extended periods. They just work… flawlessly.

Optically sublime binoculars

Optically the new SLC HD (available in 8×42 and 10×42 versions) are about as good as modern optics can get. They are practically identical to the company’s flagship birding binocular – the EL Swarovision – the only element missing in the SLC HD is the Swarovision field-flattener coating. With Swarovision the entire field of view is in sharp focus right to the edge of the frame, whereas with the SLC, as with almost all binoculars there is some variation in focus as you move from the centre to the edge of the field of view.

In the SLC the new wide angle eyepieces give an impressive field of view, the focus “sweet spot” is huge, and there’s massive depth of field, so while this focus variation is perceptible if you really look for it right at the edge of the frame, under realistic field conditions you never notice it. I’ve never compared the SLC HD and the equivalent Swarovision models side-by-side, but other reviewers have reported that the lack of field-flattener coating makes the SLCs a smidgen brighter (one less layer for light to travel through, I guess).

HD glass plus Swarovski coatings = a super bright optics

When you pair the HD glass with Swarovski’s outstanding lens and prism coatings (Swarobright, Swarotop and Swarodur) the result is an incredibly bright image even under the most challenging of conditions. In low light the image through my SLC HD 10x42s looks brighter than a view of the same scene with the naked eye… I’m not even sure how that’s possible, and it’s a little bit eerie. I’ve never looked through a pair of 8x – but their low light performance must be unbelievable!

The image, as you’d expect, is pin sharp, high contrast and the colour fidelity is spot on. I’ve been using these binoculars practically every day since mid November 2010 and I haven’t been able to glimpse even a hint of chromatic aberration in all that time. I’m still consistently amazed by their optical performance: just looking through them makes me smile.

Keeping the view crystal clear is a doddle too, thanks to the innovative Swaroclean coating on the outer lens surfaces. It makes water bead and drop off the glass, and repels dust, grease, pollen and other nasties, which makes keeping the optics spotless very easy.

Great performance in the field

In field conditions the SLC HD are comfortable, easy to use and deliver amazing clarity and sharpness across every range of conditions the Irish climate has managed to conjure up between November and mid August. If you’re not familiar with the Irish weather that’s a lot of variety. They’ve coped effortlessly with everything from seawatching in driving wind and rain, to picking out warblers in the varied dappled light of a broadleaf canopy, to coping with the glare of the sun bouncing off the Atlantic on off-shore whale watching trips.

Close focus of under 2 metres comes in handy for dragonflies and butterflies too. The twist up eye cups and long eye relief mean that (so I’m told by a spectacle-wearing birder friend) you get the full wide-angle field of view even when you’re wearing glasses.

The other thing to note is that they’re incredibly robust: tank-like build quality means that your comfortable and confident that your binoculars won’t get damaged in adverse conditions, and that they could take the occasional knock in their stride. That means that instead of being overly cautious you can really make the most of them, whatever the conditions. In all honesty I think I’d break down long before my SLCs did.

Added extras

The SLC HDs come with a really nice padded strap that’s easily adjustable using quick-release clamps – very neat! It has objective covers that attach conveniently to the end of each barrel, and a very functional rain guard that attaches to the strap and protects the eyepiece end.

There’s also a nifty little Snapshot adapter that allows you to couple your binoculars to your compact digital camera for a bit of “digibining”. It takes a bit of practice, but is certainly useful for record shots and because of the optical quality of the binoculars results can be surprisingly good.

Last but not least there’s the redesigned case or “field bag” as Swarovski calls it. It’s very nice, and pretty functional… but I use my binoculars far too often for them to live in a case… so it sits unused in a cupboard

But when all’s said and done you don’t spend this much on optics for the accessories. It’s all about the performance… and the SLC HD 42s have that in spades!

Technical Specification Swarovski Optik SLC 10×42 W B HD

From the Swarovski Optik Website

Objective lens Ø (mm)42
Exit pupil Ø (mm)4.2 / 0.17
Exit pupil distance (mm)16 / 0.65
Field of view at m/1000 m / ft/1000 yds110 / 330
Field of view (degrees)6.3
Field of view with eye glasses (degrees)6.3
Subjective field of view, apparent (degrees)61
Shortest focusing distance (m/ft)1.9 / 6
Dioptric compensation (dpt)±4
Interpupillary distance (mm/in)56-74 / 2.2-2.9
Twilight factor acc. to DIN 5838820.5
Length approx. (mm/in) [with eyecups twisted in]144 / 5.65
Width approx. (mm/in)120 / 4.7
Height approx. (mm/in)63 / 2.5
Weight approx. (g/oz)790 / 28.0
Snap Shot Adapter modelS4


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