Swarovski
15x56 SLC Review
In
my recent review of Zeiss’ 7x42 Victory FLs I extolled their virtues of
low power and wide field, so it seems a bit schizophrenic of me to say that 15x
is my favourite power for astronomy. No medication is required, however,
because in fact both 7x and 15x are my favourite powers
for astronomy, with each conferring very different strengths to the binoculars.
It is the powers in between these two hand-held extremes that I now find a bit
of a compromise.
Whilst 7x is
all about sweeping and exploring as you do with the naked eye, 15x gives a
binocular almost telescopic abilities to find and see faint objects and detail.
The problem is that the choice at these magnifications is very limited. Before
you start arguing, I’ll explain what I mean. Most 7x binoculars (i.e. 7x50s)
have a narrow apparent field and I am only interested in a 7x binocular if it
delivers a huge field of view, as the Zeiss do. At the other extreme,
most high-powered binoculars are large porro prism designs that are
much too bulky and heavy for me to hand-hold: the typical high quality Chinese
15x70s Fujinon-clones, such as those imported
by Oberwerk and Astro-Physics, are huge and weigh about 2.5kg.
Hand
held high-power (over 12x) binoculars with premium optics are thin on the
ground because their market is limited to hunters, plane spotters and
astronomers. Worse (for manufacturers) the high power puts a strain on the
optics that lower powers don’t, so high-power binoculars require particular
care in design and construction to avoid unsharp optics and too much
chromatic aberration (try a cheap pair of 12x50s and you’ll see what I mean).
I
have already reviewed two of the handful of quality 15x binoculars under 1.5kg:
the Minox 15x58 and the Leica 10+15x50 Duovids. The
obvious remaining premium contender in this category is the Swarovski 15x56 SLC
(Habicht).
Swarovski
are a major force in binoculars these days. My local dealer tells me that of
the three “Alpha” bino makers, Swarovski have by far the most modern
and high-tech factory and repair facilities. The word on the street is that
Swarovski have the best after-sales service of all. Finally, I recently
reviewed the new Swarovision version of the 10x42 EL and proclaimed
it the best binocular I have ever tested – almost perfect in pretty much every
way. So
I had hopes for the 15x56 SLCs that match the high purchase price (currently
around £1500).
Note: I’ve updated this review to
reflect the fact that following a recent service the 15x56s performed better in
respect of chromatic aberration.
At
A Glance
|
Magnification |
15x |
|
Objective
Size |
56mm |
|
Eye Relief |
13mm |
|
Actual
Field of View |
64° |
|
Apparent field
of view |
4.4° |
|
Transmissivity |
~85-90%
est. |
|
Dimensions
(L x W) |
205mm x
130mm |
|
Weight |
1290g |
Design and Build
Swarovski
produce two ranges of roof-prism binoculars – the premium ELs and the
second-rung SLCs (Habichts). The latter has a much bigger range of sizes, from
8x30 to their largest model, the 15x56, reviewed here, via various 8x42s, 7x50s
etc. The SLC range was updated a few years ago to appear as the “SLC neu”
(“neu” means “new” in German for those in doubt).
All
the SLCs are conventional roof-prism binoculars with modern features such as
dielectric prism mirrors for high light throughput and the best modern
coatings. However, until recently none had the all-important HD lenses
(containing high-fluoride glass) that the new ELs do. However, Swarovski
recently launched an HD version of the SLC, but only in the two mainstream 42mm
birding sizes. The rest of the SLC range still has to make do with outdated
lens technology and no surprise there – one of the problems with high power
binoculars is that they always lag behind the technology curve due to their
small market.
Body and Ergonomics
So
the 15x56 SLCs are the biggest and most expensive of a big range of roof-prism
binoculars; and in photos they look just that: big. Now for me big
is bad in binoculars. Indeed the 15x58 Minox were too big, so that
(if nothing else) they looked at the same time ridiculous, nerdy and slightly
menacing hanging around my neck on a Sunday afternoon stroll. So imagine my
surprise to find that the 15x56 SLCs are really quite small.
When
I say the 15x56s are small, I mean small for their format, because
of course they are much larger than say a 10x42. But they look bigger in photos
because they are quite long; in fact the barrels are slim and the whole binoculars
are not so very much wider than a pair of ELs. They are heavy, but 1290g is
modest for a 15x56, especially when you consider that these are all-aluminium,
not lighter magnesium (ELs and Leica HDs) or composite
(Zeiss FLs). Certainly 1290g remains hand-holdable for me in a way
that 1.5 Kg plus just isn’t. Below are some photos of the big Swaros next to
other binos for comparison.
Swarovski
15x56 SLCs with 10x42 ELs
Swarovski
15x56 SLCs with Nikon 12x50 SEs
Swarovski
15x56 SLCs with 12x50 ELs
Overall
external quality of the SLCs is high – similar to the ELs in fact. There is
nothing to suggest that these are a budget model (don’t imagine that these are
to the ELs what Nikon’s Monarchs are to their HG or EDG ranges, for example).
The dark green armour is also identical to the ELs and is quite attractive,
though more functional-looking than a Leica (these aren’t as pretty
as the Duovids).
The
SLCs have deep thumb depressions on the back to help with holding, which is
good, because there is a downside to the slimness Swarovski have achieved with
these – there isn’t enough space between the barrels in use (with my eye
spacing anyhow) to get my fingers between those long barrels between the
objectives and the bridge.
Other
external features of the SLC include provision for a tripod adapter (more on
that in a separate section later), single-position twist-up eyecups and a big
central focuser knob (all things you would expect).
The
SLCs are nitrogen filled and waterproof to 4m, as with any premium
roof bino’.
Optics
You
could characterise the body of the SLCs as “high quality, but conventional” and
the optics are much the same. The objectives are a triplet design, but as I said
at the start, they are not HD (i.e. they don’t contain high-fluoride glasses to
reduce chromatic aberration.) The coatings look good – much the same as the
ELs. The lenses are well recessed and the internals show some evidence of
baffling (but not the exquisite knife-edge baffles you get in a Leica).
The prisms have phase coatings, as you would expect on a modern roof-prism and
also have the latest dielectric prism coatings, so brightness should be good.
The
56mm objectives fill the barrels, which are barely 3mm thick including the
armour. If you question whether 56mm objectives are a big deal over 50mm ones,
consider that they give 25% more light gathering power. This won’t be
noticeable during the day, but certainly will for astronomy.
Swarovski 15x56 SLC objectives.
Swarovski 15x56 SLC eyepieces and focuser.
The
eyepieces look conventional, with normal sized 18mm diameter eye-lenses, rather
than the massive Nagler-like eye lenses on the new ELs. Eye relief is a
rather tight 13mm from the eye-cup, just as claimed. Field of view for the
15x56s is 64° apparent translating to about 4.4° actual field width –
both good for a high-power binocular.
The focuser on
the SLCs is swift and smooth, taking just over a turn lock-to-lock. A little
stiffer than the EL’s, the SLC mechanism doesn’t suffer from occasional
stickiness in the same way and I’m not sure I don’t prefer it. Dioptre
adjustment is different from the ELs too, by an inset knob on the front of the
main one that you have to push-in to turn and it too works well.
Tripod Adapter
This
is an optional extra, but is vastly superior to most. Instead of some
contraption of bungy straps like the adapter for Leica’s Duovids, Swarovski have
developed superb piece of kit for the SLCs; it works like this:
You
remove the penny-sized cover at the front of the binocular hinge and replace it
with a small lug that has an Allen bolt to secure it. This lug is unobtrusive
and can be left in place permanently. The adapter is a slim and elegant pillar
that slips between the barrels and mates with the lug. Tightening a clamp grips
the lug securely from all sides and the binoculars are ready to mount on a
photo tripod, either with a ¼-20 thread on the adapter base, or better by
slipping the base of the adapter directly into the dovetail shoe.
In
Use – Daytime
Ergonomics
The
SLCs are small and light enough to wear for an extended period and without
looking too odd when out walking. That’s the real benefit that you are paying
for – you simply couldn’t do that with 16x70 Fujinon’s.
The
slim design of the SLCs mean you can’t wrap your fingers around the barrels,
which makes my favourite way of holding high-power binos difficult to
achieve comfortably. I like to hold around the barrels because this reduces
shakes a bit and shakes are the big enemy of any hand-held high-power
binoculars. The deep thumb recesses are a nice effort, but they mean you have
to then rest the barrels on your palms with your elbows forwards – not a very
comfortable choice for me.
The shortish eye
relief means that without glasses the single position on the eyecups is too far
away from the eye lens and I would prefer an intermediate position
(Leica’s 12x50 HD with the same 13mm ER has an intermediate position which
works well).
The View
I
looked through the SLCs for the first time straight after using the 10x42 ELs:
big mistake. After the ELs, the most noticeable things about the SLCs were the
short eye relief and the higher levels of chromatic aberration. Having got used
to those things, the view started to look a lot better.
The
main thing to say is that the 15x56 SLCs have none of the optical softness that
spoiled the Minox 15x58s. Swarovski have clearly taken care to make
all the lenses smooth and accurately figured, with fine assembly tolerances, as
high-power binoculars require. For the view is in fact very sharp indeed, with
excellent resolution across most of the wide field. These pull distant things
really close and show a lot of fine detail. Often, you only remember you are
using 15x when you pull them away from your eyes and the thing you were viewing
disappears back into the far distance.
Best
focus is a very precise point in both barrels and requires the smooth and
accurate focus action to obtain it. No hunting for best focus is ever required
and when found it applies across virtually the whole view. Another benefit of
this optical precision is the ease with which you can exactly adjust the
click-stop dioptre setting to perfectly match your eyes.
Brightness
is good considering the high power, much better than the Minox 15x58s
and on a par with the Leica Duovids, but not quite up to the best
levels (i.e. Zeiss FLs). I should point out again here that daytime
brightness with these is not helped by the 56mm lenses, because the eye’s
contracted pupil effectively stops them down to be something like 15x40s.
Rather, daytime brightness is controlled by the transmissivity of the lenses
and prisms.
The
field of view with glasses on is narrow and not very comfortable. Swarovski
state 3° when used with glasses and that’s probably about right. It’s amazing
the difference between 13mm and 16mm of eye relief and I am again left
wondering why customers with glasses should suffer this way for the sake of an
extra 3mm, especially at the premium price. For those who view without glasses
the news is good because the 15x56 SLCs have a generous apparent field with
good flatness that delivers a very pleasant daytime view for such a high power.
When
reviewing other premium binoculars with HD lenses, such
as Zeiss FLs, Leica HDs etc, I have spoken
about “residual chromatic aberration”. I use this phrase because those
binoculars control CA well (much better than most), but look at the same view
at the same power through a small apochromatic astro’ scope and you
realise that CA is certainly still present in those binoculars if you go looking
for it. Older, pre-HD designs like these SLCs, have significant chromatic
aberration.
Update: When I first reviewed these
binoculars their CA levels were excessive and I said so. However … a few years
later I had to send them back because the seals had gone in one of the barrels.
Swarovski re-built them and lo and behold, CA levels were now not nearly as bad
as they had been.
Chromatic
aberration is now at a similar level to other premium, non-HD binoculars, not
much worse than Nikon’s excellent 12x50 SEs for example. Yes, when looking at
birds in tree branches on a bright overcast day you do get a thin purple or
green edge around feather and branch that you don’t see with the latest HD
designs. But in general, even during daytime, chromatic aberration is no
spoiler with these binoculars.
Overall, daytime performance for a
high-power binocular is really excellent – sharp, wide and quite bright. These
emphatically don’t have the dim fuzzy views you often get with higher-power
binos.
This
snapshot taken through the 15x56s gives an impression of the excellent
sharpness, but also some chromatic aberration in these very bright conditions.
In
Use – The Night Sky
The
paradox of these binoculars is that they were undoubtedly designed for daytime
use – primarily for hunting – yet they are at their very best when used for
astronomy.
The
combination of high power, high optical fabrication quality, good
transmissivity and big objectives are a killer combination for astronomical
use. The effect is very different from smaller, lower-power binoculars, even
superb ones like the 10x42 ELs. That old saw “size matters” was never more
appropriate. These show you a lot more.
However,
a note of caution: these are still big heavy binoculars and combined with
high-power accentuated shakes, they are more tiring to use than smaller,
lower-powered models. The 15x56 SLCs are
not a general purpose binocular in a way that 10x50 or 12x50s can be. Try
before you buy!
The Moon
We
will start with the Moon. I like looking at the Moon with binoculars because
you get more of a sense of the whole Moon and can enjoy the romance of watching
it drifting through rainbow-coloured ice clouds or rising over a snowy winter
forest. What’s more, I can’t see the Moon from my observatory before about Day
6 of a lunation. So I need binoculars that work well on the Moon and the
big Swaro’s do just that.
A
magnification of 15x crosses some kind of threshold when viewing the
Moon: you can see all the major craters and mountain chains in a way you can’t
with lower powers. You really need to rest against a wall or on a car roof at
this power, but if you do the super-sharp optics deliver a sensational view. Buy
a Moon atlas and you could use these to explore many of the features it
contains. When tripod-mounted, the big SLCs really show off their optical
quality with a view that is very similar to a good small refractor: perfectly
sharp, detailed and contrasty with very good resolution. Some
chromatic aberration is present, but it remains confined to the bright limb and
doesn’t spoil things.
The
Full Moon is a good test of ghosting in-field and flare when just outside it.
These are areas where “Alpha” binos often excel and the 15x56 SLCs
are no exception. Both aberrations are almost perfectly controlled – a major
bonus when working around streetlights too.
Deep Sky
Deep
sky objects are where these big-eye binoculars really excel, though. The
Dumbbell Nebula is easy to pick out, even in strong Moonlight and is clearly
hour-glass shaped. The fainter clusters, like those in Auriga, resolve into
masses of stars, patches of smoke no longer. Other more challenging binocular
objects are an easy find: the Ring Nebula, the Crab, M56 and more.
Autumn
globular clusters – M15 and M2 off the end of Pegasus, M13 and M92 in Hercules
– look especially interesting and are clearly not just the ‘faint fuzzy stars’
most binoculars show.
But
perhaps it is M42, the Orion Nebula, which really shows the 15x56s off best:
big, bright and detailed with lots of nebulosity and the Trapesium resolved,
but still with whole sword region and some of the belt for context. On a dark
night, Orion has a real ‘wow’ factor through these.
There
is still enough field width to enjoy star fields and The Pleiades look
beautiful with pin-point stars across a flat field. The outstanding optical
quality gives stars that are small, sparkling and natively colourful – Albireo
shows off its colours through the 15x56 SLCs.
Planets
As
with any prismatic optics, these are not planetary instruments! However,
Jupiter’s disk is perfectly round with no spiking whatever and when
tripod-mounted I believe I can see a hint of the equatorial belts. The Galilean
Moons are perfect pin-points and can be resolved even when very close to each
other or just emerging from occultation. Venus is very bright and some
unfocussed light spoils the view as it does with any and every binocular.
Saturn shows a clear “handled” shape as Galileo drew it; move your eye around
and you can just make out the rings.
All-in-all
astronomical performance is simply outstanding for hand-held binoculars.
Summary
The
15x56 SLCs are a rarity amongst high-power binoculars. During the day they give
very sharp and high-resolution views across a wide field. Even brightness,
often a bugbear with high power binos during the day, is good. Yes they could
do with more eye relief if you wear spec’s; yes, they have more chromatic
aberration than the latest HD designs. But overall daytime performance is
excellent.
At
night, however, the chromatic aberration isn’t a problem. Instead the high
optical quality and big-eye objectives give views that bridge the gap between
binoculars and small refractors, but with none of the softness that beset
the Minox 15x58s and with more reach (and a bigger field) than
the Leica Duovid 15x50s. The optical quality is so good that these
even do well on the planets (given the limitation of 15x, obviously).
On
deep sky these just show you more ... even than Nikon’s 12x50 SEs or
Swarovski’s own 12x50 ELs. Given their performance, (relatively) small size and
light weight, and the fact that they are fully fog-proof, these make a great
astronomy binocular, particularly if you like hunting down fainter members of
Messier’s list.
Add in the premium Swarovski build and reputation
for service, and you have a strong argument that these are the best
hand-held astro’ binos I’ve reviewed. But I’m not going to make them a reference standard for three reasons:
1)
They are a bit specialist: some will find their
weight and power-induced shakes tiring or irksome in a way 12x50s aren’t.
2) They really should
have HD lenses (latest versions do).
3)
They need a bit more eye relief for spec’s wearers.
The
Swarovski 15x56 SLCs get my highest recommendation for hand-held astronomy
binoculars and should be great for their intended hunting and spotting market
too. However, check you can live with their weight and shakes (and the tightish
eye relief) before you buy.
