Zeiss Jena Notarem 10x40B mc Review

My original review of Carl Zeiss Jena’s Notarem 10x40s was one of my first, posted over a decade ago. It frankly wasn’t up to the thorough standard I aim at these days.

Now I’ve done the decent thing and bought another pair for a more in-depth test. Right now is a perfect time to re-visit this pair of ‘classic’ binoculars too, because I seem to be having something of a season reviewing bino’s in this style, what with Zeiss’ own 7x42 Dialyts and a pair of 1980s Leitz Trinovids in the queue as well (not to mention the similar-looking Leica Trinovid Classics).

Part of the reason for this is just that I like old and quirky things. They have a mid-century look that’s come back into style, too. But there’s a practical interest, because this style of binocular gives you the size, weight and handling of a modern 10x32 with most of the light gathering ability of a 10x42. The downside being, of course, a lack of full armour and waterproofing.

Buying and using a classic like the Notarems also confers the under-appreciated advantage of minimal depreciation.

I was impressed with both the Leica Retrovids and the Zeiss Dialyts – both offer a genuine alternative to modern cookie-cutter roofs. Are these Notarems as capable? Let’s find out ...

The Notarems next to a pair of 2020 8x40 Leica Trinovids.

At A Glance

Magnification	10x
Objective Size	40mm
Eye Relief	~12mm
Actual Field of View	105m/1000m, 6.1°
Apparent field of view	~60°
Close focus	~5m
Transmissivity	80%?
Length	152mm
Weight	620g claimed, 646g measured.

Data from CZJ/Me.

Design and Build

The Notarems look funky and retro nowadays, with their long slim barrels and leather cladding. But back in the mid-1980s, when these were manufactured in East Germany, that’s mostly how roof-prism bino’s looked: for example, Leitz’s Trinovids and Zeiss Oberkochen’s (the separate West German company) Dialyts, but lots of lesser-known models, like Swift’s Trilytes, too.

Back then, Zeiss Jena made a smaller 8x30 Notarem in the same style and an armoured version that was the same binocular but with a ridged rubber sheath squished over it.

At that time, the Zeiss Jena factory was making some 200,000 binoculars per year, with a variety of models including the traditional Jenoptem porro-prism binoculars pictured below. To set the expectations for this review, it’s perhaps worth noting the difference between those Jenoptems and a pair of porros from that other Zeiss factory, at Oberkochen in W. Germany (see below), one of the finest-built binoculars I’ve ever encountered.

For reference, a pair of fairly basic Zeiss Jena porros from the same factory as the Notarems and a pair from Zeiss West at Oberkochen. The latter have a real ‘Swiss watch’ feel.

Body

Holger Merlitz has an image of a Zeiss Jena catalogue from the era of my Notarems on his website and it makes interesting reading. It seems that these little bino’s have quite a complex design, but from the outside they just look tiny and dainty for a 10x40. That is certainly a major appeal of the Notarem. They make today’s armoured roofs look bulky and heavy. Unsurprisingly, though, they are very similar to a pair of traditional Leica Trinovids (or their re-issued ‘Retrovid’ equivalent).

At 620g the Notarems are the weight of a modern 8x32. No modern 10x42 from a premium make weighs so little. Even Swarovski’s 10x40 Habichts or Leica’s 10x40 Trinovids weigh a bit more.

I really like the metal-and-leatherette finish, but as with other classic roof designs – such as Leica/Leitz Trinovids and Zeiss’ Dialyts - these are not fully sealed and purged. However, the Zeiss Jena catalogue claimed “special sealing against adverse dust and climatic conditions”, so they are not as vulnerable to the odd rainy day as they look and again this is just like most other similar binoculars.

Make no mistake that back in the day, before purged and sealed birding bino’s were universal, folks managed fine with binoculars like this, often (I’m told) just thoroughly drying them out after a wet day in the field. Problems typically only arise when they’re stored away damp.

Focuser

The Notarem’s focuser is unusual: both eyes are independently adjustable via the central knob, but just enough resistance is built-in to ensure that you can focus them together once you’ve set them relative to each other for your eyes. Two little arrows line up to show they’re at neutral.

This seems a more intuitive system than the right-eye dioptre adjustment that was all but universal in the 1980s and is still common today.

Internally, the focuser is even more unusual. Most binoculars focus by moving the eyepieces or the objectives or a focusing lens between objective and prism (the default adopted by most modern roofs). These use none of the above. Instead, the field-lens part of the eyepieces moves with respect to the rest of the eyepiece (which remains fixed). It does so by sliding in and out of the eyepiece barrel in a finely fitted and greased (!) tube. The tube is in turn moved by a simple lever mechanism actuated by a screw attached to the focusing wheel.

Enough of the techy details, so how well does it work? The focuser knob is small and fiddly compared to modern designs, but is reasonably smooth and not too sloppy or vague.

It does suffer some play, so dioptre tends to wander a bit as you focus. This can always be fixed by a bit of re-focusing which seems to settle things. Alternatively, savvy repair shops can usually improve the mechanism (something I had done to good effect with my original pair).

Close focus isn’t up to modern standards, though – at about 5m it’s too far for me to get an accurate measurement. You do get a feature most don’t have – a red dot and infinity marking, like a camera lens. From close focus to that infinity mark is about ¾ turn – fast, even today.

Optics - Prisms

The Notarems apparently employ a mixture of roof and penta prisms to keep the weight down. Like ordinary roofs, these do need mirror coatings, which were reputedly silver, giving them their warm image tone according to some sources.

Phase coatings appeared in the late Eighties - a few years after these were made - so these miss out, meaning that contrast and resolution will be a bit down on modern designs. Lack of phase coatings seems more obvious at higher magnifications (Leitz’s 7x35s don’t seem to suffer as much from it).

The prism mountings aren’t the most robust and a knock can send the Notarems out of collimation. Once again, that’s a fault that can be fixed with some upgrades to the prism straps, something offered by some repair shops as part of a service.

Optics - Objectives

The Notarems have achromatic doublet tele-objectives with a large air gap and the crown at the front. The big gap between the elements improves false colour correction (Zeiss’ high-end 20x60 image stabilised bino’s have the same design), but it’s also a good choice for ruggedness: no cement to deteriorate (so-called ‘balsam failure’) or narrow gap for water to become trapped.

For stray-light protection, the space between the elements is ridge-baffled and there is a large knife-edge baffle just in front of the prisms.

The brochure advertised ‘T3M’ multi-coatings, indicated by the ‘mc’ engraved below the left eyepiece. The coatings have a dark purple / gold appearance: much more transparent than the usual lilac single layer of magnesium fluoride. Transmissivity is not up to the best modern standards, but is actually quite good on this pair.

Optics - Eyepieces

The eyepieces are 6-element, wide-field Erfles. Considering that most binoculars of the era had basic Kellner eyepieces, that’s quite sophisticated, but as I’ve said it also allows them to use an unconventional focusing mechanism. Those complex eyepieces give a true field of 6.1° (about 60° apparent): quite wide for a 10x bino’.

Eye relief is supposedly sufficient to warrant rubber folding eye cups and is the meaning of the ‘B’ in the bino’s designation. This doesn’t mean properly modern eye relief, though – I measured about 12mm from the rim of the folded eye cup. That’s enough eye relief to be usable with glasses, but not enough to see anything like the whole field.

Accessories

Like most quality binoculars of the era, the Notarems came with a lovely tan leather hard case lined with plum velvet and a (maybe not so lovely for all-day carry) thin leather strap. The neoprene Zeiss strap shown above is modern, fits fine and is far more practical.

Originally, both individual objective caps and an eyepiece cap were supplied.

In Use – Daytime

My first pair were faulty and I sent them off for a service at one of the UK’s most respected optical repair companies. Three weeks and ninety quid later, back they came much improved. The invoice said they had been cleaned, collimated, had the prism mounts strengthened and the focusing repaired. Thereafter they worked well.

This more recent pair didn’t require any intervention, but collimation and focusing, whilst serviceable, were not as good as the repaired pair. Clearly, those prism and focuser upgrades are worthwhile if you intend to use the Notarems regularly.

Ergonomics and Handling

If you’re used to modern roofs with thick armour, these Notarems feel remarkably small and slim. With big bear paws that might be a problem, but it’s a comfortable hold for me – fingers curled around the barrels.

So the long-barrelled design makes them generally easy to hold and the focuser comes nicely to hand. But they do suffer an odd ergonomic fault. The strap attaches to lugs built into the body on the underside behind the eyepieces and so interfere with my nose when viewing. To avoid this, I have to curl my thumbs around the strap ends to fold them out of the way. A modern neoprene strap works better.

These Notarems are the “B” model, which implies more eye relief and fold-down eyecups to accommodate it. They do indeed have more eye relief than traditional 10x bino’s (like the Jenoptems) and are quite usable with glasses, but that way I lose a substantial part of the fairly wide field. In fact, the most comfortable option for me turns out to be with the cups folded down but without my specs on.

Focusing has a nice snap to it and is smooth and quite fast, but there is only just enough travel beyond infinity to accommodate my eyes uncorrected; Mr Magoo would need his glasses to use these. As I mentioned, dioptre can wander a bit as you focus in and out, but this typically improves with use and a bit of re-focusing usually snaps it back in.

The View

For users without glasses, the view is pleasingly wide. Brightness seems quite good. Sharpness is good too and you don’t immediately notice the lack of phase coatings. So, the view generally seems quite bright, sharp and detailed.

However, careful comparisons with more modern designs reveals that indeed these do lack a bit of resolution thanks to the absence of phase coatings. They’re a bit dimmer too, even than a pair of 1990s Zeiss Dialyts - significantly dimmer than a pair of modern 10x42 Zeiss Conquest HDs.

Perhaps the most obvious issue to modern eyes is one typical of older Zeiss binoculars – a definite yellowish tint that is really obvious if you swap between these and a modern binocular. I don’t know if this was simply the glass of the time, the coatings, or a deliberate distortion to allow better performance in misty conditions (some binoculars of the era were supplied with yellow filters). You do get used to it, though.

Flat field?

The fairly wide field isn’t flat, but distortions only creep in at about 80% of the width. But thereafter, those distortions are quite severe by modern standards (see below).

Chromatic Aberration

Chromatic aberration is well controlled for a pre-HD roof, thank those tele-objectives with their huge air-gap and the lack of a dedicated focusing lens (often a source of false colour in modern roofs).

Stray Light and Ghosting

Viewing a bright but distant security light produced one small bright ghost and four long dim prism spikes – not too bad and better than I expected.

Aberrations in the last ~10% are quite severe by modern standards, but otherwise it’s a well-corrected field.

In Use – Dusk

Brightness during daytime seems quite good, but these are dimmer in deep dusk than a 10x40 with modern coatings. This is noticeable as a loss of detail and contrast compared to the modern optic under the same conditions. Still, I could make out lots of detail in the copse opposite in strong Moonlight.

Viewing under a brilliant dusk sky caused some mild veiling flare from the bottom of the objectives only.

In Use – Observing the Night Sky

On the night sky the Notarem 10x40s work surprisingly well, one of the better older designs I have tested.

The field is nice and wide and flat until the last 10%; stars are pinpoint and bright with good colour. They don’t go as deep as a modern premium 10x42 would, but they are basically fine for casual astronomy.

The Moon

The Notarems give an excellent view of a bright gibbous Moon – sharp and detailed, albeit not to the level of a pair of modern super-premium 10x42 SFs I’m testing at the same time. Compared to the modern bino’, the Notarems’ Moon is a little warmer toned too.

Mars

The only bright planet around was just a bright star, with no flare ghosts or prism spikes on view.

Deep Sky

10x40 bino’s with modern coatings (like Swarovski’s Habichts or Leica’s Trinovid Classics) can work well for deep sky and these old Notarems aren’t as dim and useless as you might expect.

The brighter DSOs of late winter looked good. The Orion nebula looked much as it does through any 10x birding binoculars. I easily found the clusters in Auriga and resolved the arcs of stars that comprise the Pinwheel and Starfish (M36 and M38). The Pleiades looked less brilliantly sparkly than a pair of premium 10x42s, but the whole cluster easily fitted without distorted stars.

Fainter DSOs are not ideal targets for older binoculars with lower transmission. I found globular cluster M3 easily enough, but it was a bit dim and indistinct for this aperture. I might have glimpsed M1 (the Crab Nebula) in Taurus, but wouldn’t swear to it with my hand on the Good Book.

Summary

In 1985, when I was just finishing my student days, when a superbike boasted 100 horsepower and a home computer had 16K of memory, the Notarems must have had state-of-the-art performance. The world has changed a lot since then.

The Notarems are still a nice binocular, especially my original pair (following the attentions of the repairer to fix the wandering dioptre and slightly suspect collimation that most suffer as standard).

They are very small and light, even today. By comparison, a modern Zeiss 10x42 of whatever type will be much bigger and heavier.

The view is decently wide and bright by modern standards and the focuser, once repaired and strengthened, works fine. Sharpness is well down on the best phase-coated roofs, but probably not much worse than cheap ones; ditto twilight performance. Optical quality appears pretty good, better than cheap binoculars today.

So should you buy a pair? Well, the Notarems’ design weaknesses can be readily fixed for the price of a thorough service. Given their typical price used, you might thus pay £200-300 for a fully fixed pair in near-mint condition. That’s similar to a pair of new Nikon 10x42 Monarchs, for example. Those Nikons will outperform the Notarems, but be worth much less when it comes time to sell.

So, if you just like the Notarems’ classic style, with its nostalgic roots in the 1960s, they make a cheap alternative to Habichts, Trinovids or Dialyts – tuck a pair in the breast pocket of your moleskin jacket and let’s go watch a steam train.

The Zeiss Notarems are cautiously recommended as a classic, but factor in ~£100 for repairs to make them fully usable.