Swarovski 10x42 SLC HD –

Optics Editor Don MacDonald field tests a new pair of binos from the Austrian maestros...

Over the past few years I’ve been lucky enough to review and field test top of the line Swarovski gear. This includes the Z6 riflescope and the fantastic EL range of binoculars. These items are pretty much the best of the best in terms of hunting optics, so when the NZ Ammunition Co sent me a pair of new midrange SLC 10x42s I was a bit more reserved when the green box arrived. That was until I opened it... Damn it Swarovski, you’ve done it again!

Not content with redesigning the EL range, Swarovski decided to give their old SLC (Slim, Light, Compact) binoculars a work over as well. This was not in the way of new emblems or smaller neck strap mounts, but a full reworking including changes in the chassis design. This is now made of lightweight alloy again instead of magnesium, making it lighter than the old model.

Less expensive than the heavier El range, the SLCs (Slim, Light, Compact) are hunter-oriented.

The SLCs have been fitted with new wide-angle eyepieces and the diopter adjustment is now built into the focus dial, allowing simple one-finger adjustment. One of the biggest deals about the new SLCs however is that although they are fitted with the same fluoride HD glass and coatings as the old model, the new model has been fine-tuned optically. Now before I go any further, I feel it important to say something about HD (high definition) and Swarovski optics. Swarovski is trying to pull away from the term “HD”. Why? Because“HD” is currently being used and abused by every optical, camera and television manufacturer. Everything is HD now. There is nothing really special about this any more and there’s no real justification or defining factor that separates one HD product over another. The marketeers are just portraying a rudimentary level of clarity.

An example is that my good but less expensive Minox binoculars are also HD, yet they’re of course in a very different league from a pair of Swarovskis. This is why Swarovski is now using the word Swarovision instead of HD in their EL and ATX range which I’m eagerly waiting to review. This has put their clarity level back at the top away from the masses with HD branding. With Swaro in the name the optical quality is untouchable, something for other manufacturers to compare their products with and aspire to. Even though the SLCs on review are still labelled HD you probably need to think of them as “Swarovision’s little brother”, and way ahead of HD labelling.

As their designation implies the SLCs are semi-compact binos weighing in at 790 grams for the 10x42 model. They are considerably smaller than the EL range with overall measurements of 144mm x 120 mm x 63mm. This compact size allows for a single pivot between the two barrels. The pivot seems like a simple design on the outside but it incorporates the focus dial with its 1.5 turns of focusing adjustment. Also incorporated into this is the right barrel diopter dial. This is a straightforward push/pull system with a 4+/4 – adjustment range offset toward the left barrel. 

I found this a little confusing at first as the increments are more centralised in the EL range but I soon discovered the raised reference mark on the front face of the left pivot point.

On the underside of the barrels are the thumb indentations that dictate a comfortable and natural position for holding the binoculars. Having a natural position like this is important with heavier binos as they can cause cramping in the carpal tunnel area of the wrist with extended use. Along with these there are strong neck strap connection points that hold the SLCs steady against your chest unlike some binos that seem to twist around as soon as they get the chance. The last external feature is the new twist-up eyecup design. These three stage units provide comfortable positions for those with either 20/20 vision or eyeglasses, and the cup size does not restrict or decrease the visual field whatsoever.

A really comfortable neck strap is a bonus for carrying binos in rough country.

The SLCs are fitted with fluoride-containing lenses surface-coated with Swarovski’s unique range: Swarobright, Swarodur, Swarotop, and the all-repelling Swaroclean. The SLCs have a claimed light transmission percentage of 91% and measured exit pupil of 4.2mm. Along with this they have a 16mm eye relief and a field of view of 110m @1000m or 330ft @1000 yards. As with all Swarovski products they come with a robust case, lens caps and one of the most comfortable neck straps money can buy. Models available in the range are an 8x42, 10x42, 8x56, 10x56 and for really reaching out, a 15x56.

Testing optics is very subjective when it comes to visual clarity and many writers, including myself sometimes, tell you nothing by saying an optic is clear. For this reason I always back it up by running a resolution test using the industry standard USAF chart. Set at a mandatory distance of 30 yards the SLC provided a resolving score of 0.011” in the horizontal plane and 0.010” in the vertical, and that’s over 75 to 80% of the visual field. As a comparison ELs will discriminate black lines 0.011” thick and the same distance apart over the entire field, making the SLC very good performance-wise for the price.

The second thing I do is get no less than five or six people to use the optics and give me their opinion on perceived brightness and clarity. This second test is sometimes the most important as it involves real people, real conditions and real situations. The general comments from others looking through the SLCs were “these things are clearer than my eyes,” and “you could keep glassing with these non-stop for hours”. One comment that I couldn’t agree more with is that the SLCs provided a deep “three dimensional” type image that you don’t often get with optics.

They’re out there somewhere! Don was able to pick out these three tahr easily at over a kilometre distant.

With a twilight factor of 20.5 and the fact that animals obviously appear brighter in daylight I was keen to see how they stacked up in low light conditions. The 3D effect mentioned above seems to allow shadow and shape to have more depth, making objects more obvious and thus perceivably brighter; even more so than the EL range.

For the tech-minded reader, the twilight factor is the square root of the product of the diameter of the objective lens and the magnifying power. For example, an 8x32 binocular has a twilight factor of 16, and a 10x42 has a twilight factor of 20.5.

This is always the easiest part of the review when evaluating Swarovski products due to the high quality of the company’s manufacturing processes. All the moving parts were smooth and precise. The pivot did have a heaviness or tightness to the mechanism but once set the distance between your eye and the lens stays put and you are not adjusting it constantly as with some binoculars.

The centre pivot is only slightly bigger than one of the twin pivots on the ELs but it is incredibly strong and it would take something pretty extreme to bend the barrels out of alignment. The outer coating of the SLCs is durable and washable. During a tahr hunting trip they inadvertently got covered in blood and hair. Thankfully this rinsed off with water very easily!

When I’m field-testing Swarovski products I plan as many hunts as possible as an excuse for keeping them as long as possible. The first day out was a short hunt in the Mackenzie for a stag that I had seen the week before. Glassing for this beast was a pleasure with the SLCs; they provided a beautifully clear picture with that three-dimensional feel I was talking about. The group of deer and the big stag I had seen previously were nowhere to be found, but this did force me to glass for long periods up and down the valley from dull light of dawn into the morning glare as the sun crept over the main ridge. At all times I could see things in great detail with the SLCs.

Dropped with the .300 Weatherby Magnum, the good-sized Mackenzie country spiker filled Don’s freezer.

With good depth of field and good resolution it didn’t take me too long to spot a couple of red spikers at well over 1km away. Stalking in to around 150 yards I watched them for a while and enjoyed the experience of studying animals in their own environment through great optics. The need to fill the freezer eventually took over however, and ended with a shot from my .300 Weatherby Mag. On the next hunt I went in behind Lake Tekapo for tahr. This was another good test for the SLCs as the tahr had started to don their winter coats and the greyish colouring is often difficult to identify, making the animals hard to spot among the rocks, bluffs and screes. Once again the extra resolution really made a difference to how fast I could pick up distant animals in a camouflaged situation.

The SLC range has always been targeted toward hunters and it’s one of the reasons some of the bird-watching features have been omitted, like the snapshot adapter and the ability to focus on really close objects – you might use your binos to study a bush robin from five metres away but not an approaching stag! These absent features have the advantage of making the Swarovskis a little more affordable for the hunting consumer.

Overall the 10x42 SLCs are another excellent product from Swarovski – I really enjoyed testing them in the field and yet again was reluctant to send them back. Their compactness and usability meant they never were left at home during the time I had them and I was able to spot distant animals easily. For marks out of 10 for quality of manufacture, optical quality and style/usability I would give a 9, 8.5 and 9.


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