10x50 is the classic format for astronomy. Meanwhile other members of Swarovski’s EL range are among my favourite binoculars. So, put the two together and you should have a fantastic instrument for exploring the night sky. In this review, I find out whether the Swarovski 10x50 ELs live up to that theory.

Swarovski 10x50 EL Review

Many regard 10x50 as the ideal astronomy binoculars. Being a rebel at heart I’ve generally preferred higher magnifications and bigger lenses, but recently I’ve realised how tiring those big bino’s are to hold (having reviewed a clutch of them). So as an antidote to all those big-eye behemoths, I decided to try out the 10x50 format in one of my favourite binocular ranges – the Swarovski EL.

At A Glance

Magnification

10

Objective Size

50mm

Eye Relief

20mm claimed, ~15mm measured

Actual Field of View

6.6 degrees

Apparent field of view

63 degrees

Close focus

2.5m

Transmissivity

~90%

Length

174mm

Weight

999g

Data from Swarovski

What’s in the Box?

Note: The style of box and case may differ in your country.

Design and Build

The ELs were for many years Swarovski’s premium range. As of now (late 2022) the 42mm and 50mm models all remain in production, though the 32mm have been discontinued. The 32mm and 42mm models have been superseded by a new top-line binocular, the NL Pure.

The ELs originally came in various sizes from 8x32 to the 12x50 I reviewed a couple of years back.

Body and Ergonomics

It happened again! When I reviewed the 12x50 ELs I had to double check they hadn’t sent me 10x42s by mistake. This time I again found myself checking to see if they were the smaller model: they really don’t seem much bigger or heavier, though in reality they weigh 150g more and are slightly longer and chunkier. Even so, you get the point – the 10x50 ELs are compact for the format. They are nothing like those big 10x56 SLCs and Zeiss Conquests I’ve been testing (which is a good thing).

Part of the reason for their (relatively) low weight is that Swarovski use magnesium alloy for the body, not aluminium like the cheaper SLCs.

I really like the slim, open bridge design of the ELs and that metal bridge looks much classier than the plastic hinge of an SLC HD. I prefer the subtle-but-classy look of the Swarovski ELs to the rather showy styling of the Zeiss HTs.

The armour is slightly different in texture from the SLCs’, but just as grippy and non-rubbery.

 

Compact body has thumb cutouts on the back.

Focuser

The focuser is fast, taking about one and a quarter turns from close focus to infinity. Precision is perfect, with no play. The action is quite smooth but suffers from the occasional ‘stiction’ that afflicts most greaseless focusers.

Dioptre adjustment is effected by pulling the focuser knob to reveal a scale. Turning the focuser now adjusts the dioptre. It’s similar to the old Zeiss Victory FLs’, but lighter yet more positive with a click-stop mechanism. The scale is numbered in half-dioptres too and appears accurate, so if you know your prescription you can just dial in the difference.

 

Pull the focuser to adjust dioptre. Those numbers accurately reflect your difference in prescription.

Optics - Prisms

The EL range all employ conventional Schmidt-Pechan roof prisms complete with SWARObright dielectric mirror coatings and of course phase coating too.

Optics - Objectives

The objectives are an air spaced triplet design that includes one or perhaps two HD elements.

All the latest coatings are applied – SWAROtop and SWAROdur. They also have the SWAROclean coating that repels dirt and water like Zeiss’ LotuTec.

From what I can see, there is a single knife edge baffle behind the objectives and ridged baffles in the focuser tube. The objectives are well recessed to help prevent flare, but don’t have the micro-baffled ring in front to cut flare like some (for example) Zeiss binoculars.

Darkened lens ring, excellent coatings and knife-edge baffles behind the lenses.

Optics - Eyepieces

The eyepieces are a six element design that includes a field-flattening lens. The eye lens is big and deeply recessed, from whence the eye relief problem comes (see below): it’s no use designing a long-ER eyepiece and then burying the lens deep in the eye cup.

I could bore for Britain about eye relief, but it winds me up that there is no consistency, even within a single maker. These 10x50 ELs are a case in point. Swarovski state 20mm, but I measure it at more like 15mm from the eye cup rim. Whatever the precise figure, it’s about 3mm less than my Zeiss 7x42s which are stated at 16mm and much less than Swarovski’s own 10x56 SLC HDs which are rated at 19.5mm. This isn’t splitting hairs – the difference between 15mm and 20mm is between annoyingly tight and … ahhhh … complete relaxation at the eyepiece.

In practice, eye relief is enough to see almost the whole field with specs on, but only if I push my glasses into my face slightly with the bino’s.

To compensate for the relative lack of eye relief, there are no kidney-bean blackouts with glasses and only occasional minor ones without.

Field of view looks quite wide on paper at 6.6 degrees true (115m at 1000m), but feels even wider because that field is so flat.

The eye cups have three extended positions and Swarovski’s usual exemplary twist-out action.

Three extended eye cup positions. The first has very little extension.

Accessories

The ELs come with Swarovski’s semi-rigid field case as standard. It’s an excellent item with a soft lining and separate compartment for accessories. It is designed for both 50mm and 56mm models, so it’s on the large size for these ELs.

Swarovski’s standard premium ‘lift’ strap and band-on objective covers are included.  Note that the new ‘FieldPro’ version (late 2015 on) has integrated caps and special strap.

Semi-rigid field case is nice but big (it fits the 56mm models too).

Swarovski 10x50 EL with (pre – FieldPro) strap and caps fitted.

In Use – Daytime

Ergonomics and Handling

Comfort is state of the art. The 10x50 ELs handle like a smaller binocular and don’t feel as heavy as they are. The double barrels are very comfortable and secure to hold. The armour is grippy but not rubbery and doesn’t attract marks and dirt like some (Zeiss).

The focuser is easy to use and precise, though I still prefer Nikon’s HG focuser to any greaseless design like this one. Dioptre is very easy to set and impossible to knock out accidentally. The eye cups work better than any other with very positive click-stops.

The only demerit on the comfort front is that shortish eye relief. According to the brochure ER is super-generous, but none of the EL models I’ve tried has more than adequate ER in practice. I can’t quite see the whole field with specs on and it feels tight – if I stop pushing them into my glasses, I lose a bit more field width. It’s enough – but only just.

Panning is surprisingly comfortable considering they are a flat-field design (see note below).

Unlike many (most) larger-objective binoculars, the EL 10x50s look elegant and unobtrusive when carried. In other words you won’t look out of place in a group of birders all wearing 8x42s.

Swarovski 10x50 ELs don’t feel like a big binocular to hold.

10x50 ELs look like a regular birding bino’ hanging around my neck.

The View

The daytime view is the very best: wide, sharp, bright, full of finely-resolved detail edge to edge and with great depth of field and virtually no nasty false colour fringing. Colours are very naturally rendered but still vivid; perhaps just a shade warmer than my Zeiss Victory FLs.

It goes without saying that optical fabrication quality is the very best. Focus snap is absolute and collimation super-comfy perfect.

The fantastic thing here is that you just aren’t making any compromises at all for the big lenses – these perform like the very best small birding binoculars during the day.

Close focus performance is outstanding for such a high-power, big objective design. I can easily focus on objects across my study, but the barrels don’t merge as well as the 42mm version very close up (less than 3m).

I experienced no ghosting and only fleeting veiling flare when viewing around a low sun.

Flat field?

The field is a bit wider on paper than the 10x56 SLC HDs’; but it’s also much flatter, so all of it is usable. That make these 10x50 ELs feel as if they have a wider field than the SLC HDs, superb though they are.

Because even the field at the stop is sharp and usable it seems the field is completely flat; it isn’t. In fact Swarovski have added just a little pin-cushion for comfortable panning so these don’t create the rolling ball effect I saw recently in Zeiss’ big 15x56 Conquests. It’s an ideal compromise for me.

Chromatic Aberration

Correction for chromatic aberration is among the very best, slightly better than my Zeiss 7x42 FLs. I watched a crow teetering on the top of a nearby conifer against a brilliant sunny sky, with perfect definition and no false-colour rim around his black feathers.

In Use – Dusk

The 10x50 ELs work very well into deep dusk as you would expect, but are not quite up to the latest big-eye models with high-transmission Abbe-König prisms. These 10x50s give slightly less ‘light-intensifier’ effect in full night than 56mm models.

In Use – The Night Sky

The view at night is characterised by the same high levels of comfort as during the day. For some reason this is a pair of binoculars I could really relax with, perhaps due to the wide flat field, perfect optics and modest weight.

Contrast is supreme and really helps tease out faint DSOs.

Stars remain stars across the whole field, with just slight blurring near the very edge. Even there, the slight remaining pincushion can be focused out (there is no significant astigmatism).

Ghosting and flare suppression are not the very best at night. A bright security light in field caused a faint ghost. Bright lights outside the field cause minor veiling flare. However, there was no ghosting with the Moon in-field and very fleeting and minor veiling flare around it.

The Moon

The 6-day Moon looked about as good as I’ve seen it at 10x, with just a trace of false colour on the limb but very sharply defined otherwise. Resting on the car in my drive, I could see significant Lunar detail on the terminator – rugged Janssen, the mountainous rim of Mare Nectaris, Proclus with it bright rays near Mare Criseum, Hercules and Atlas in the north.

Planets

Jupiter looked as good as it ever does in binos – a sharply defined disk with no significant flare or spiking surrounded by the Galilean moons as perfect points.

Venus was a tiny dazzling disk with no flare or spiking either.

Saturn, though very low and small in the dawn, showed its Galilean ‘handles’ (all you can make out of the rings at this magnification) and a distinctly pinkish-yellow hue.

Deep Sky

Despite being ‘only’ a 10x50 (I’ve recently reviewed a number of 10x56 and 15x56 models), the ELs are absolutely first rate on deep sky. I’m going to go into some detail here for prospective astronomy users. Feel free to skip down to the comparison section if you’re not interested.

The view of the Great Nebula in Orion on a clear night was the best I’ve had through binoculars, period. I could make out the dark lane and sharply defined ‘arms’ as if through a telescope. With averted vision I could see variations in the nebulosity – something I’ve never seen with hand-held binoculars before.  

I also found it very easy to find relatively small, faint DSOs, something I wasn’t expecting of a 10x50. I quickly picked out the Crab Nebula in Taurus. I found various galaxies without difficulty – M51 and M101 in Ursa Major; M96 and M105 in Leo. Bode’s Nebula was very bright and easy to find, the two galaxies looking quite different from one another, not just faint smudges.

The tight stars and high contrast make for a beautiful view of clusters. M35-38 in Auriga, including the Starfish (M38) and Pinwheel (M36) clusters, were a silvery mist of separate stars. Their characteristic shapes were easily visible. I could just fit M36, 37 and 38 into the same field of view and enjoy them together – only possible thanks to the flat field.

The Double Cluster looked fantastic – masses of pinpoint stars, including the two red ones (AD and FZ Per) in the middle and the Heart Nebula region nearby in the same field of view.

The Andromeda galaxy – M31 - looked very bright and well defined. On the opposite side of Mirach, M33 was very bright and distinct too.

On a later night, I was able to pull various dim DSOs out of the Moonlight, including the Crab, Bode’s and even M15 near Enif in Pegasus and the Dumbbell Nebula, despite both being very low in the sky.

I could go on. Perhaps you can tell, I had a fantastic few nights of deep sky observing with the Swarovski 10x50 ELs. Despite their modest aperture and power, they are among my very favourite astronomy binoculars. I became addicted to using them and wasted hours enjoying their view.

Enjoying the Dumbbell Nebula with the 10x50 ELs

Swarovski 10x50 EL vs Swarovski 10x56 SLC HD

This is an obvious comparison, so let’s summarise the main contrasting features of these two state-of-the-art 10x binoculars.

·       The ELs are 200g lighter and 2cm shorter, but the difference feels even greater than the numbers suggest

·       The ELs are much more elegant, but basic build quality is the same

·       The ELs have a flatter and wider (115m vs 110m at 1000m) field

·       The SLC HDs have much more real-world eye relief

·       The SLC HDs are a touch brighter during the day and significantly brighter at dusk or at night thanks to their bigger objectives and Abbe-König prisms

·       Both binoculars are among the very best for suppressing false colour

·       The SLC HDs suppress ghosts and flare a little better

·       The focuser is essentially the same

·       The view is just superb through both

·       Their compact size (but not the view) make the ELs a more general purpose binocular

·       List price is about 20% more for the ELs

Summary

I absolutely love the 10x50 ELs. Larger binoculars have a bit more reach, smaller ones slightly better portability, but taken in the round these are among my favourite binoculars ever, simple as that.

On the one hand the daytime view is simply the best: bright, wide, flat, sharp, with really outstanding resolution and contrast and almost no false colour. The view for astronomy is as good as it gets too – wide and steady for lovely views of star fields and clusters, but deep and contrasty enough to find smaller DSOs and show nebular detail in larger ones.

On the other hand, these are a small and reasonably light binocular, a real relief after reviewing some big 15x56s. They handle like a large 10x42 and so are much more comfortable and manageable than big-eye binoculars.

There are a couple of downsides: a trace of ghosting and veiling flare on a bright artificial light is pretty much just academic. But that tighter-than-advertised eye relief is a minor annoyance.

All in all, though, these come the closest yet to being the perfect all-round binocular – outstanding for everything and still very manageable to carry. Overall, I slightly prefer them to the 12x50 EL for their steadier, wider view. If I had to own only a single pair these would be a contender.

The Swarovski 10x50 ELs get my highest recommendation. I’m tempted to buy a pair.