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The 10x42mm Zeiss SFs are among the very best bino’s money can buy and one of my absolute favourites. Are these 10x32s as good?

Zeiss 10x32 Victory SF Review

Now that Zeiss have fixed their early build quality issues, the 42mm SFs are among my very favourite binoculars. I like everything from their unique shape and handling, to their wonderfully bright, sharp and wide view. For astronomy I do just prefer Swarovski’s NL Pures, but for birding I might opt for the SFs, that’s how much I like them.

Recently, Zeiss have expanded the SF concept into 32mm binoculars, pricing them as a more compact alternative, not a cheaper one. So Zeiss finally have a competitor to Swarovski’s 32mm ELs, but at an even higher price: these are (I think!) the most expensive 32mm bino’s currently on sale.

So are these smaller-but-not-cheaper SFs as good as their larger siblings, or have Zeiss had to compromise to squeeze the SF concept into a smaller format?

And there’s another question I’d like to answer: are the very finest 10x32s any use for astronomy? Let’s find out ...

At A Glance

Magnification

10x

Objective Size

32mm

Eye Relief

19mm claimed, ~17mm measured

Actual Field of View

7.6°

Apparent field of view

69°

Close focus

1.95m stated, ~1.7m measured

Transmissivity

90%

Length

150mm claimed, 147mm measured!

Weight

590g measured.

Data from Zeiss/Me.

What’s in the Box?

Zeiss have upgraded ... the box! Now the SFs get an even fancier one with a magnetic catch and an even more striking nature photo:

Design and Build

The SFs don’t have a Zeiss heritage like say the HTs or older Victory FLs. Instead of building on previous great Zeiss bino’s, like the Dialyts, the SFs were a totally new design when they emerged five years ago.

The SFs aren’t really like anyone else’s bino’s either. Their open bridge looks a lot like Leica’s Noctivids’ or Swarovski’s ELs’, but the SFs are a much more radical re-design than just putting an open bridge on a Victory HT.

Radical in what way? The SFs have a different optical design from other premium models, as we’ll see. That optical re-think has a knock-on effect on the appearance and handling too. So the SFs have a unique style and feel and view. I’ll go into the technical details in the following sections.

Zeiss clearly see the SFs as a pure birding (as opposed to hunting) binocular, so they only make four classic sizes: 8x42, 10x42, 8x32 and these 10x32s. I’d love to see an astronomy-worthy 10x50 or 12x50, but I’m not holding my breath.

Body

The SFs are an open bridge design like Swarovski’s ELs, with long simple barrels that lack thumb-indents or other sculpting to fit the hand.

The first thing I noticed about the 42mm SFs back in 2015 was just how long they are. The 32mm models are the same. This is puzzling, even off-putting, at first: the 10x32 SFs are just plain large for their aperture. How large? Let’s compare ...

These ‘little’ SFs are 30mm longer than the 10x32 Victory FLs they replaced as Zeiss’ top model and compared with the cheaper Conquests, they’re longer too - 16mm longer. Put it another way, they are 5mm longer than a pair of 42mm Leica Ultravids. The 10x32 SFs’ most direct current competitor – Swarovski’s 10x32mm ELs – look similar but are almost a centimetre shorter. Odd, then, that Zeiss overstate their length at 150mm when I measured 147mm!

Large the 32mm SFs may be, but like the 42mm models they’re light for their size: about the same as those Swarovski 10x32 ELs and only 40g more than the much smaller 10x32 Victory FLs.

Zeiss’ philosophy with the SFs seems to be that weight and handling in a bino’ matter more than size for most people. They might be right.

The old Victory FLs pioneered a composite (yeah alright, plastic) body construction. I liked it because it was warmer to hold in freezing conditions. For the SFs, Zeiss have reverted to a magnesium alloy. Possibly plastic premium bino’s made life hard for the marketing department, but more likely it’s because the open bridge was difficult to implement in composite.

The two-finish black armour is smooth on the barrel insides, lightly textured and flattened on the outside for a more comfortable grip. The open bridge sections are left as coated bare metal, just as SW and Leica do with their similar designs.

The SFs armour is well fitted, hardly smells rubbery and whilst grippy it isn’t too much of a magnet for dust and prints. It’s a big improvement over the HT’s armour and now looks and feels almost identical to Leica’s. In photos it looks like the armour on Zeiss’ cheaper Conquest HDs, but it’s not – theirs is more rubbery, fluff collecting and markable.

 Like all modern Zeiss, the SFs are nitrogen filled and immersion proof to 4m.

Focuser

The 42mm SFs have one of the best focusers and this is the same. It’s not the very fastest, but in terms of fluidity, intuitiveness and absolute precision, they just don’t get any better.

Swapping between a pair of basic Conquest HDs and these, the focuser (not the view or the handling) is the first thing you notice: the Conquests’ focuser is good, but this is much more fluid and intuitive. In a sense it’s also necessary, because the focus snap of these SFs is so extreme you need the most precise focuser to find it.

I measured close focus at ~1.7m, which is very close for a 10x binocular and slightly better than Zeiss state. Even more impressively, they do actually merge comfortably at that distance. From close focus to infinity is about 1 Ľ turns of the outsized and twirly wheel.

Dioptre adjustment on the SFs is by a separate knob at the front of the bridge, which you pull out to adjust. It’s smooth, accurate and a has positive détente for neutral. Compared with Swarovski and Leica the only thing it lacks is a scale.

 

Optics - Prisms

The SF have modern-standard Schmidt-Pechan (a.k.a. Roof) prisms, not the low-loss Abbe-König prisms of the HTs. Zeiss quote the 32mm SFs at 90% transmissivity, much the same as other Alpha roofs but 2% down on the 42mm models.

Optics - Objectives

One of the many interesting things about reviewing bino’s is finding unexpected design features. Although these 32mm SFs seem like (and are marketed as) a scaled down 42mm SF, optically and mechanically they’re different.

Like the larger SFs, these employ a long-focal-length doublet with an Ultra-FL ED glass crown, instead of the usual triplet, to reduce weight. But instead of focusing with a moving lens behind the objective, here the objectives themselves move on a carriage behind a thin optical window. Those promo’ images aren’t photoshopped, the pink circles at the barrel ends look flat because they are!

Moving-objective focus isn’t new - most Canon IS bino’s work that way. But it is unusual in a top-line Alpha bino’. Advantages might include better false colour suppression (the focusing lens can be a source of chromatic aberration). The downside is another optical element in the light path, perhaps explaining part of that 2% loss in transmissivity compared with the 42mm model.

Perhaps it also explains the exceptional T* coatings: Zeiss’ signature pink, but even darker. And it doesn’t stop there. Shining a bright light into the objectives, there isn’t a single reflection that isn’t dark pink, perhaps the first time I’ve seen such complete coatings.

Here, T* means something different from T* on a Conquest HD, whose pink coatings are noticeably more reflective (see below). As a an aside, I recently compared the 8x42 Conquest with the 8x42 SF and found a much more subtle difference in their objective coatings.

The lenses have micro-ridge-baffled rings, but internal baffling seems minimal, which is ... baffling, because stray light suppression seems good.

Objectives move on carriages, seen here, to focus.

Zeiss SF (top) and Conquest HD (bottom) both supposedly have ‘T*’ coatings ...

... as do these 16 year old Zeiss Dialyts. T* is variable!

Complex SF eyepieces have seven or possibly eight elements (Zeiss image).

Optics - Eyepieces

The SFs’ eyepieces, with their almost-flat 25mm eye lenses, are a complex design. Zeiss’ original SF cutaway showed seven-elements, but a recent animation shows even more! All those air-glass surfaces may help explain the 32mm SFs’ 2% lower overall transmission figure.

So why, then, do these small SFs need some of the most complex bino’ eyepieces in current production? Partly optical performance: a combination of high eye relief and a wide, well-corrected field in a compact design. But complex eyepieces are also part of Zeiss’ ErgoBalanceTM concept: a combination of light objectives and heavy eyepieces move the balance point backwards and takes torsion off your wrists

Real world eye relief is a few millimetres down on the claimed 19mm at ~16mm and less than the 42mm models. It still feels plenty with my glasses, but that’s thanks to the super wide field. In fact, I can’t quite see the whole field with my specs on and this is an area where these 32mm SFs lose out to the originals.

Apparent field of view at 69° is among the widest of any current Alpha binocular, exceeded only by Swarovski’s new NL Pures. That translates to an impressive 7.6° true field (130m/1000m). Compare the 6.9° offered by SW’s 10x32 ELs and the meagre 6° of the 10x42 Nikon SEs which were once my 10x reference standard.

One of the few negative things about the 10x32 SFs is more blackouts and sensitivity to eye position than I’d like. Another is the eye cups ...

The 8x42 SFs I tested recently had excellent eye cups, but on these 32mm SFs the action is stiff and rough. I’m not even sure if there are meant to be two positions or three. I don’t know if this is sample variation, but such expensive bino’s deserve better.

SF (top) and Conquest HD (bottom) have completely different coatings on their eye lenses.

Accessories

These 10x32s have almost the same list price as the 10x42s and their design is several years more recent. So why have Zeiss dropped the rather stylish slim case of the 42s for a much more basic Cordura item hardly different from the Conquest HDs’?

The neoprene strap is standard Zeiss, with no equivalent to Swarovski ‘Lift’ strap or ‘Field Pro’ quick release system. The caps are standard too, though for some reason, the eyepiece cap for the SFs is less flexible and rubbery than the Conquests’.

In Use – Daytime

Ergonomics and Handling

Zeiss’ ErgoBalanceTM concept, that throws the weight backwards and off your wrists, worked for the bigger models and it does for these too. Those long barrels make for a secure and comfortable hold, even with gloves.

Eye relief for use with specs is really excellent for a 32mm binocular, but is still a little tighter in reality than the 42mm models’ and I can’t quite see the whole field with my specs on (not that noticeable, because the field is so wide). Another possible comfort issue is blackouts ...

My daughter found the SF 10x32’s blackouts so annoying she didn’t like using them. I wouldn’t go that far, but they are a genuine downside. You don’t notice them on a static view, but start to pan or swivel your eyes and you get regular kidney-bean patches flash into the view.

As I said above, the focuser is the very best: the ultra-large wheel has a light, fluid feel and is super accurate. More importantly, the focus point is identical focusing in or out (it often isn’t). That and the super precise focus snap make finding focus super-fast and easy, a real feature of these SF 10x32s.

The 10x32 SFs may be large for a 32mm binocular, but they’re still light and unobtrusive to carry. I think they look great too.

The 10x32 SFs’ long barrels give them a full-sized hold.

The View

The view is outstandingly good, especially for a 32mm bino’. Pin sharp, with extreme focus snap, it feels vivid and full of crystalline high-res detail. Brightness is excellent and colour rendition cool and natural. The most remarkable thing is that field. At 69° apparent, it’s a proper wide field, putting the field stop in your peripheral vision and giving an immersive airiness to the view. I’ve said it before, but narrow fields are hard to go back to.

Such a wide field means that there’s no need to drop back to an 8x binocular if you can hold 10x steady: the true field here is as wide as many 8x32s.

I only really started to appreciate how good the 10x32 SFs are taking them on long walks, birding and nature viewing. Detail is staggering. I can ID birds at extreme range, including on the wing. The filigree of winter woods across the bay is stunningly rendered, every twig picked out and visible. Resolution is so high that I spot things in the villages on the opposite shore that I’ve never noticed.

Nearer to home, Blue Tits, Coal Tits and Great Tits at the feeder show every blue, yellow and black feather. I notice that the Great Tit’s yellow breast feathers overlap the darker plumage on his back in delicate sprays.

So, the view is exceptionally fine for a binocular of this size. But is it quite as good as the 10x42s’? Hmmm ... In most ways it really is. However, I can’t explain why but it doesn’t feel quite as relaxed and easy somehow.

Flat field?

Like many premium bino’s these days, the SFs have field flatteners in their eyepieces. But flat seems to mean different things to different folks. To an astro’ imager flat means flat – pinpoint stars to the edge. To Swarovski, flat means a completely usable view at the field stop. For the SFs, neither of those things is quite true.

Yes, the SFs have a more viewable field edge than Leica’s Ultravids. But, typically for Zeiss, they have included a little field curvature to make panning more comfortable, at the expense of some blurring towards the field stop. Viewing a ruler (yes, geeky, I know) shows that the field degrades gradually from 50% until the fine scale isn’t quite readable in the last 10%.

The Zeiss compromise is best for birding or nature viewing where you’ll be panning about a lot. But for more static use – from a hide or for astronomy – I’d take Swarovski’s.

Chromatic Aberration

These smaller SFs are essentially free of chromatic aberration. The objectives generate no false colour, something you can see focusing through layers of silhouetted branches.

Then there are the eyepieces, which are often a source of false colour off-axis. But here, most unusually, there is almost no false colour in the distorted edge part of the field, where other Zeiss models have a lot.

The upshot is that a crow’s black feathers silhouetted against a bright cloudy sky are un-spoiled by purple or green fringes. Panning through branches there are no flashing false colours to distract and annoy. Use in the brightest conditions, over snow or bright water, induces no contrast-reducing purple wash.

An internal focusing lens is known to make false colour worse, so is that why Zeiss have ditched it in favour of moving objectives for these newest SFs? If so, it worked ...

In Use – Dusk

Despite the smaller objectives, these 10x32s function well into dusk, albeit not as well as the 42mm version. I watched my local badger ambling about in the copse at twilight, wrongly confident he was unobserved (we call him Mr Scratchy due to his horrible habits on my lawn).

Under a brilliantly clear dusk sky I got no veiling flare at all, whatever I did. Contrast the 8x42 SFs which gave a little under identical conditions and Leica’s Ultravids which gave a little more.

In Use – Observing the Night Sky

I was keen to find out how the very best 10x32s would fare for astronomy. Why? Because 32s make a great travel bino’ and travel often takes you to dark skies.

Few binoculars give such pinpoint stellar images centre field. Off-axis, stars stay perfect until ~70% field width. After that, a tiny bit of distortion creeps in, but you can focus it away – it’s just mild field curvature. Only in the last 10% of this very wide field do stars become slightly astigmatic, but it’s not intrusive for astronomy. My usual test of squeezing both the belt and sword of Orion into the field, results in only very slight distortion of Mintaka and Nair al Saif at the periphery.

Very, very few binoculars give such an absolute focus snap on stars: the tiniest breath on the wheel nudges it to perfection. But this has a downside. The focuser is so light that it’s all too easy to nudge it out of focus again, especially in the dark with gloved hands.

In other respects, comfort is good for astronomy. The light weight and rearwards balance help reduce fatigue. I like the long barrels which allow a hold around the objectives for extra steadiness. Those blackouts noted during the day didn’t trouble me for astronomy.

Viewing a very bright security light generated four long dim prism spikes, but no ghosts with the light in field and no flare when viewing around it.

The Moon

A crescent Moon was a perfect view – sharp and contrasty, full of tiny crater detail and with no false colour, minimal flare.

Mars

The Red Planet wasn’t at its brightest, but still focused down to a tiny dot different from a pinpoint star, with no spikes or flare at all.

Testing the 10x32 SFs on deep sky.

Deep Sky

Conventional wisdom would have it that 32mm bino’s can’t do deep sky, but these can ...

The hugely wide and pretty flat field means sweeping the Milky Way is addictively enjoyable, the field stop receding into peripheral vision to leave you immersed in a vast and spacious star field. It’s an effect I’ve previously experienced only with SW’s NL Pure.

Panning up through the Milky Way from Deneb, I find a distinct patch of misty nebulosity which is the North American Nebula. Further up, the star fields are wide, rich and enthralling. I stumble across open cluster M39, nicely resolved, that leads on to many more clusters which have only NGC numbers.

Surely not galaxies with a 32mm? Panning either side of orange star Mirach in Andromeda, I easily find M31; On the other side, M33 is easy too and is really picked out well, showing some shape, more than just a vague misty patch. After some averted-vision searching, I locate M51 in Ursa Major, not so much the Whirlpool galaxy as the faintest smudge, but there it is nestling in the darkness off Alkaid.

The obvious stuff looked good too. The Pleaides were sparkly, with the sharpest pinpoint stars. The Double Cluster and nearby Stock 2 resolved lots of stars in a rich and super-wide field. Only at the edges was a narrow band of minor blurring. Panning over into Cassiopeia, I happened upon the Owl cluster off Ruchbah.

The clusters in Auriga – M35, M36 and M38 were all starting to resolve with direct vision, once my eyes had fully adapted. Only M37 remained star-mist. The Beehive open cluster was dimmer than I’m used to, but showed all the major stars in their distinctive pattern.

Brighter nebulae look good too. Orion’s sword region revealed a surprising amount of glowing nebulosity. Meanwhile, the belt region was densely populated with stars – more so than I expected. I was really astonished to find that with averted vision I could pick out M1 (the Crab Nebula) across in Taurus, something that troubles some 8x42s.

One thing smaller apertures don’t do so well is star colours. The Garnet Star, a rich amber even in 7x50s, looked pale gold; ditto La Superba.

The Zeiss 10x32 Victory SFs were certainly not built for astronomy, but their wide field, supreme optical quality and premium coatings mean they work amazingly well.

Zeiss 10x32 Victory SF vs Zeiss 10x32 Conquest HD

Zeiss’ ‘budget’ range, the Conquest HDs, are a really excellent binocular, especially in the smaller sizes. The SFs are almost three times the street price, so what extra do you get for your money?

·        The SFs are larger but lighter

·        The SFs’ long barrels and rearward balance makes for a comfier hold

·        The SFs have nicer armour – less rubbery and fluff attracting

·        Centre field view is very similar

·        The SFs may have slightly higher resolution centre field, but not by much

·        The SFs have a wider, better corrected field

·        SFs’ brightness seems only a touch better, if at all

·        The SFs appear to have much better coatings, especially on the internal elements

·        The SFs have a little more eye relief, but worse blackouts

·        The SFs focuser is much more fluid and intuitive, even though the Conquests is good by general standards

·        Zeiss quote identical 90% transmission and indeed brightness seems about the same

·        The Conquests’ optical quality is excellent, these SFs have some of the best I’ve ever seen in a binocular, evident on star images

All those little refinements do sum up to make the SFs a significantly nicer binocular ... but three times nicer? Go ahead and treat yourself to the SFs, knowing the Conquests were probably all you needed.

Summary

There’s no question that the 10x32 SFs are the best 32mm binoculars I’ve ever tested. Smaller bino’s once had a narrower field, less eye relief and a dimmer view in return for a lower price. No longer.

The view is super-wide, well-corrected and full of brilliant high-contrast detail. The focuser is among the very best. Handling is great: I like the long barrels for secure and steady grip, appreciate the rearwards balance point. Optical quality is peerlessly high, giving some of the best stellar images I’ve seen. So forget the 10x42 SFs and buy these then? Hold on ...

These may be the best 10x32s and the view is the equal of the 10x42 model in most ways, even exceeding it in sheer width. But there are a few areas where these 10x32s fall short. The eyepieces have a bit less eye relief and rather worse blackouts – they feel tighter and less easy somehow, requiring more careful positioning. The same goes for the view: it’s just as bright, vivid and crystalline; but less easy, less relaxed (a feature I really value in the 42mm SFs).

Then there is simple physics: 42mm objectives grab 70% more light than 32mm ones. So although these smaller SFs do work remarkably well at dusk and for astronomy, the 42s will inevitably work better at lower light levels, in winter or at dusk, go deeper on the night sky.

Meanwhile, the price difference between 32mm and 42mm models is small. So the question is really whether losing 200g of weight and 25mm in length is worth a slightly less relaxed and capable binocular? If you’re traveling, hiking or trekking, then yes. For regular birding, maybe buy the 10x42s and a harness.

If you really need the smaller size and weight of a 32mm binocular, these are the best I’ve ever tested. But they cost almost as much as the 10x42 SFs and don’t quite have their easy grace in use.

 

Buy Zeiss 10x32 Victory SF from Wex here:

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