Swarovski’s 15x56 SLCs have long been my favourite astronomy binoculars. The new SLC HDs are even better, but these Zeiss Conquests significantly undercut their price and throw in a tripod adapter as well. In this review, I aim to find out if they’re really better value.

Zeiss Conquest 15x56 HD Review

I have just finished reviewing Swarovski’s new SLC HD 15x56s and they are a stunning high-power binocular – a big improvement on the already excellent old (confusingly called ‘Neu’!) model.

These Zeiss Conquests sit at a lower price point than the SLC HDs - Zeiss regard them as ‘upper mid-range’ - but they are still made in Germany, unlike the old Hungarian Conquests. And they still come with a great warranty too.

So is the extra cost of the ‘near perfect’ Swarovski 15x56 SLC HDs worth it, or are these new Conquests 15x56 HDs really the Zeiss equivalent, but just priced low to elbow out the competition?

At A Glance



Objective Size


Eye Relief

18mm claimed

Actual Field of View

4.6 degrees

Apparent field of view

69 degrees

Close focus








Data from Zeiss

What’s in the Box?

Is it me, or are Zeiss making a big effort in the box presentation department? People love a good unboxing and Zeiss are really adding ‘wow’ factor to the experience.

Design and Build

Zeiss have brought the Conquest range bang up-to-date. They now have those all-important HD lenses to reduce false colour fringing, but they also get a new body and armour that has the Zeiss house look. The eyepieces are different too – a wide field design with massive eye lenses like the best premium models.

As we will see, there are a few specific areas where costs have been cut, but basic build quality – mechanical and optical – is typically Zeiss and much like the premium HT.

Body and Ergonomics

First impressions of the Zeiss Conquest 15x56 HD are that they are very similar to the much more expensive 10x54 Victory HTs I tested last year. Everything about them, from the tapering shape to the thick two-texture armour looks similar.

In fact, these are quite a bit longer (210mm vs 193mm) and heavier (1275g VS 1050g) than the HTs. They’re larger than Swarovski’s 15x56mm SLC HDs too, closer in size to the old model in fact.

These Conquests have a more conventional design than the HTs, with an armoured hinge and the focuser at the back, rather than the HT’s characteristic double-link bridge and huge central focuser.

Zeiss don’t sculpt the back for thumb cut-outs, unlike the SLCs which now get a two-stage cut-out that really makes for a snug fit in the hand.

Internal construction looks good; and rugged. But it appears slightly more agricultural, with a few more rough surfaces and obvious grease, than a pair of Zeiss Victorys.


Conquest 15x56 HDs are larger and heavier than Swarovski’s 15x56 SLC HDs.



The focuser is smooth, precise and fast, taking less than a turn from close focus of ~3m to infinity. I noticed a little play in the focuser of the 10x56 Conquests, but not in this one – blame it on sample variation.

It’s a similar story with the dioptre adjustment. It’s a conventional ring below the right eyepiece with no click-stop and no locking mechanism. The ring was too stiff on the 10x56s I tested; on these 15x56s it’s fine.

Optics - Prisms

Like the 10x54 Victory HTs (and the new Swarovski SLC HDs) the new Conquests get Abbe-König prisms. These give greater light throughput because they don’t need lossy mirror coatings – they bend the light around using total internal reflection like porro prisms. In this case, the transmission quoted is 90% (less than the HTs which are quoted at 95%). As we will see, though, these are a very bright binocular thanks to those prisms, just like the Zeiss FLs and Dialyts before them.

Note that only the 56mm Conquest HDs get Abbe-König prisms – the 42mm and 32mm models have conventional Schmidt-Pechan roof prisms.

Optics - Objectives

Zeiss claim HD (i.e. high-fluoride) glass for these, but as we will see these don’t have the very low chromatic aberration levels that some HD designs have nowadays. I suspect that both Zeiss’ 54mm HTs and Swarovski’s 56mm SLC HDs employ two ED elements to curb false colour, whereas these have only one (which is why they are long – to accommodate longer focal-length objectives that also improve false colour).

The Conquests’ objectives are well-recessed with micro-ridged lens rings and two large knife edge internal baffles for stray-light suppression.

The T* coatings on these Zeiss Conquests are absolutely top quality. They have a slightly pinkish hue that gives a cool colour balance. They have the latest dirt-shedding “LotuTec” feature as well.


Similar models from Swarovski, Zeiss and Nikon. Nikons’ coatings are worst and they have more ghosting as the result.

Optics - Eyepieces

The eyepieces have very large (25mm) eye lenses, like the 10x56 model, that suggest a sophisticated design. They also yield a very wide (for binoculars) apparent field of 69 degrees – right up into wide-angle territory, like an astro’-eyepiece. Unfortunately, eye relief isn’t up there with the finest astro’ eyepieces.

Oh how I wish manufacturers would be consistent about eye relief. Zeiss quote 18mm, just like the 10x56 model and more than Swarovski’s competing 15x56 SLC. But actually they have less than either – around 14mm by my measurements, which makes it impossible to see the whole field with my specs on. Part of the problem, as usual, is the deep ridge running around the rim of the eye cups.

Blackouts (spherical aberration of the exit pupil) aren’t an issue unless you get the eye cup position wrong. The exit pupils look properly round and un-vignetted; internal reflections are well suppressed too.

The adjustable eye-cups have only two positions (many premium examples have three). This is a problem for me because (without specs) I found I needed an intermediate position.

Compared to the best, the eye cups are soft-feeling and the action is a bit stiff, but there’s no sloppiness the way there was with the 10x56s I tested.

Deeply recessed eye lenses reduce the eye relief with the eye cups screwed in as far as they’ll go.


The Conquest HDs come with the usual Zeiss cordura case and typical straps and stay-on caps.

A very good quality, Zeiss logoed tripod adapter is included for free (Swarovski take note). This may sound a minor point, but if you want one it adds an extra ~£100 to the price of the SLC HDs for a similarly classy device from Swarovski.

The included tripod adapter is a quality item.

In Use – Daytime

Ergonomics and Handling

The Zeiss Conquests handle well, but there is no getting away from their size and especially their weight. For me these pass a threshold where I find them tiring for long periods of use.

The lack of thumb cut-outs doesn’t really matter, because you are always going to end up holding these around the objectives to reduce shakes.

I don’t like recent Zeiss armour, which is smooth and tacky and attracts dust and marks. It’s too much like the armour found on cheaper brands.

Other comfort aspects are good. The focuser is a delight to use – fast, smooth and precise. I don’t like this type of dioptre adjustment as well as the click-stop type found on the old Victory FLs, but it’s very easy to use with just the right weight (the 10x56s’ was much stiffer).

These are a huge pair of binoculars hanging around my neck. No sneaking down the promenade for a peek at moonrise, pretending I’m birding, with these. I’d probably be arrested for spying on the Heysham nuclear plant across the bay.

Zeiss Conquest 15x56 HDs are a big binocular.

The View

The view is very bright and sharp, contrasty and detailed. Subjectively, resolution appears excellent. Colours are on the cool side of neutral. Focus snap is perfect in both barrels and dioptre adjustment is very easy – all a sure sign of high optical quality.

Depth of field is good for a high-power binocular and 3-D effect better than many too.

The ultra-wide field of almost 70 degrees is noticeable in use and gives a nice sense of ‘room to breathe’ in the view. It also means that the off-axis aberrations noted aren’t the big problem they would be in, say, a 55° field of view.

The high power allows you to do things you couldn’t with lesser binoculars. I watched a pair of squirrels collecting Beach nuts in a tree 150m away.

The daytime view is very good for high-power binoculars.

Flat field?

The field is not as flat as the Swarovski 15x56 SL HDs’, but flatter than the 10x56 Conquests’. Despite the wide field, these don’t have the marked off-axis field curvature and astigmatism that beset many Zeiss binoculars, such as the 7x42 FLs (or indeed the 10x56 version of these Conquest HDs). The view is still usable at the field stop.

Chromatic Aberration

It’s back! After reviewing several pairs of binoculars with very low levels of chromatic aberration, these do show some false colour. Centre field it’s well controlled – not as well as the 10x56 model and certainly not as well as Swarovski’s 15x56 SLC HDs - but not intrusive.

However, start panning around silhouetted branches and you get those flashing colours I so dislike. A pair of Jackdaws on a high branch in the copse opposite, silhouetted against the sky, show a thin rim of purple and yellow I can’t focus away.

But the problem here is off-axis, where things get worse. By the last 15-20% of the field width, false colour is more severe, with purple fringes on high-contrast parts of the view.

Don’t think the false colour ruins the daytime view, it doesn’t. But for viewing birds in flight, like raptors, you might choose the Swarovski SLC HDs instead.

In Use – Dusk

Dusk penetration is astoundingly good with these. I generally prefer 10x56s at dusk but these had a strong light-intensifier effect in dawn twilight too, revealing detail in shadows quite black to the naked eye. These would make a great hunting binocular.

In Use – The Night Sky

The very wide field gives these Conquests a view like a small refractor with a wide-field eyepiece - a Tele Vue Delos, perhaps. It’s just a shame you can’t see all of it with specs.

That field is very flat too and stars remain star-like to the edge, unlike the Conquest 10x56s, which turned stars into lines near the field stop. Stars are particularly small and tight through these, another sign of top optical fabrication quality.

I found a little veiling flare around streetlights and a few very faint spikes (less than through the 10x56s). A very bright security light revealed a few very faint ghosts. Stray light performance is thus a notch below the Swarovski SLC HDs.

Focus on stars is particularly snappy which makes for super easy dioptre adjustment, even at night.

Just about the only “problem” for me is the sheer weight – my arms quickly get tired keeping these steady.

These are such a strong astronomy binocular I will spend a bit more time on their detailed, object-by-object, performance for anyone interested:

The Moon

Views of a 26 day old crescent in steady dawn seeing were among the best I have ever had with binoculars. These are so sharp and contrasty that I could make out telescopic levels of detail: dark-floored Bailey; Schickard and Phocylides near the terminator; Aristarchus full of shadow and mysterious Reiner Gamma on Oceanus Procellarum.

There was a trace more chromatic aberration on the very limb of the Moon than you get with the SLC HDs, but it didn’t spoil the view in the least.


Venus was too small to show its gibbous phase, but the view of it was very crisp and tight with no spikes, flare or significant false colour.


Jupiter showed a perfectly clean disk free of flare or spikes and I could make out the Galilean Moons well into bright dawn twilight.


I got a surprise view of Saturn very low (7 degrees altitude) in a dawn sky. Even though the planet was small (just 13 arcsecs or so) I immediately spotted the ‘handles’ which are the way its rings show up at this power. I think I also caught a moon or two.

Planets through hand-held binos just don’t get better than this.

Deep Sky

The view of the chain of clusters running up into Auriga from M35 was more involving than through smaller binoculars. Each cluster resolved into its component stars and showed its characteristic shape - faint fuzzies no longer.

The Double Cluster in Perseus was very bright and full of stars. For a moment I struggled to pick it out from all the other little clusters nearby that these reveal.

The globular cluster M15, lying just off Enif in Pegasus, was very easy to find and looked bright and its nature obvious.

The Andromeda Galaxy (M31) showed its bright central core and extended arms much more clearly than through the 42mm binos I was using alongside. M33 was much brighter and more obvious too. Those big lenses and bright optics really work for deep sky.

Supported on a tripod, these big Conquests showed the Orion Nebula large and bright with much more sense of its shape than you usually get with binoculars – bright curving arms, sharp cut-off to the nebulosity and ‘spike’ in the middle. The Trapezium was an easy split. The whole of Orion’s sword region fitted in the field of view without the distorted stars at the edge which spoiled the same view through the 10x56 version.

Albireo looked especially lovely through these, with its colours – orange and blue – very strong.

Astronomy performance is the very best available in hand-held binoculars, a tie with Swarovski’s SLC HDs.


Night testing the Conquest 15x56s

Zeiss Conquest 15x56 HD vs Swarovski 15x56 SLC HD

So how do these very similar binoculars from two top European brands compare?


·        The Swarovskis are shorter and 90g lighter.

·        The Swarovskis have a narrower (63 vs 69 degrees) but even flatter field.

·        The Swarovskis have a couple more millimetres of eye relief –not in the brochure, but in the real world.

·        The Swarovskis show significantly less chromatic aberration centre field and much less towards the edge.

·        The view through the Zeiss is otherwise as bright, sharp and detailed as the Swarovskis. Optical fabrication quality is every bit as good.

·        The Zeiss focuser is lighter and faster but less oily smooth. Overall it’s just as good, though.

·        Some aspects of the Swarovskis – the eye cups and the armour – show higher build quality.

·        Zeiss throw in a top-quality tripod adapter.

The Swarovskis are the more perfect binocular, but they are also about 30-40% more expensive.


Zeiss’ 15x56 Conquest HDs are an excellent pair of binoculars. The view at this power is as good as it gets, apart from the false colour – bright, sharp, full of detail and the very widest. Build quality is good and the focuser excellent. Optical fabrication quality is amongst the very best I’ve seen. In many ways they are better than the 10x56 version because they have a flatter, wider field with a lot less off-axis curvature.

The only real downsides are chromatic aberration during the day, which is at a higher level than the SLC HDs (and even the Nikon Monarch 5s), especially near the edge. These are also a bit bigger and heavier and have a millimetre or two less eye relief if that matters to you. Ghosting is just a touch worse than the essentially-perfect SLC HDs.

I’ve just finished testing three binoculars in this class – Swarovski’s SLC HD 15x56s, Nikon’s Monarch 5 16x56s and these Zeiss Conquest HD 15x56s. Each is separated by about the same amount (~£500) in cost. Which hits the price/performance sweet spot for astronomy? Easy  - these Conquests! Why? Performance is very similar to the SLC HDs at night, but these are much cheaper and come with a free tripod adapter. Meanwhile, the Nikons are a much more compromised binocular and you don’t get the German-made promise of long term support.

If you can manage the weight, the Zeiss Conquest 15x56 HDs are highly recommended and an astronomy binocular best buy – almost as good as the SLC HDs, but much cheaper. For raptors, you would choose the Swarovskis for their lower daytime false colour and easier handling.