A Work Commenced November 9 2023

Preamble

Product: Zeiss Terra ED 8 x 42

Country of Manufacture: China

Chassis material: Polyamide, reinforced fibreglass

Exit Pupil: 5.25mm

Field of View: 125m@1000m(7.13 angular degrees)

Eye Relief: 18mm

Light Transmission: 88%

Close Focus: 1.6m advertised, 1.8m measured.

Coatings: Zeiss multicoating, LotuTec hydrophobic coatings on outer lenses

ED Glass: Yes(Schott ED)

Waterproof: Yes

Nitrogen Purged: Yes

Weight: 725g advertised, 728g measured

Dimensions:14 x 12cm

Accessories: padded logoed neck strap, clamshell case with zip lock, microfibre cloth, instruction sheet, rain guard and objective covers

Warranty: 2 years

Price(UK): £449.00

It’s been almost a decade now since Zeiss introduced their line of entry-level binoculars encompassing the Terra ED series. A few years back, I did a thorough test drive of the small pocket model and was duly impressed with its optical and ergonomic quality, I even investigated whether the quality of the original Japanese-made models of the Zeiss Terra ED Pocket were the same as their newer Chinese manufactured counterparts, finding that there was no discernible differences in performance between them. In this review, I’ll be reporting on the full-size 8 x 42 Terra ED.

During my investigation of the pocket model, I was contacted by a Zeiss Rep, who helped clarify many details about the Terra pocket binoculars but also offered some general comments on the philosophy behind Zeiss breaking into the mid-tier binocular market. She told me that their goal in marketing the new Terra ED line was to achieve ‘’best in class performance.’ She also told me that in the early days they were having some problems getting their Chinese employees to apply the coatings on the lenses to the standards established by Zeiss but that was close to being resolved. Fast forward a few years and I now feel that I have a truly mature product with all the initial manufacturing bugs having been eliminated.

First Impressions

I ordered up the instrument from Amazon. The package arrived in fine condition. The box was brand-new with no signs of tampering. I chose the plain, black-coloured model. Inside I found a nice quality storage box with a pretty alpine picture inside the top cover to whet my appetite. The instrument was found inside a well-made Cordura case – a scaled up version of that accompanying the pocket models. This is a far cry from the soft pouch that accompanied earlier incarnations of the same instrument.

The box also contained an instruction sheet with warranty information, a high-quality Zeiss microfibre cloth, and a good, wide, Zeiss-logoed neoprene strap. The instrument was located inside the case with the rubber rain guard and objectives covers attached.

I was pleasantly surprised when I took the binocular out for initial inspection. Zeiss apparently gave the larger Terra models a makeover in 2017, using a thicker rubber substrate to armour the re-enforced fibreglass chassis. It’s much more grippy than that found on the pocket models, smooth on top and nicely textured on the sides of the barrels. Unlike a number of other reports I’ve read, there was no strong smell from the rubber either. The Zeiss blue logo sits pretty on the broad single bridge.

Tipping the scales at just over 700g, the instrument possesses a median weight among 8 x 42 roof models I’ve tested. The large central focus wheel is superbly tuned. It rotates extremely smoothly with no play in either direction. Just shy of one full revolution clockwise brings you from closest focus(1.8m measured) to infinity and beyond. This is a very fast focussing mechanism – ideal for birding, as I was to discover.

The right eye dioptre is sensibly located under the right ocular lens and is fairly stiff to turn – a good thing surely. I’m glad Zeiss didn’t go for one of those gimmicky plastic locking dioptres found on similarly priced $500 binoculars, which are likely to malfunction sooner rather than later. Indeed, I personally don’t consider locking dioptres to be that desirable.

The eyecups are excellently designed. Covered in soft rubber, they are extremely comfortable to rest your eyes against.  Four locking positions are offered, quite enough for most users. Unlike the 10 x 42 model, the eye relief is plenteous enough to image the entire field easily with ordinary glasses.

The objective lenses are nicely recessed. They have immaculately applied antireflection coatings that make the lenses almost disappear when viewed head-on. The large ocular lenses make centring one’s eyes easy and intuitive too. Zeiss had the presence of mind to include their proprietary LotuTec hydrophobic coatings to the outer lenses to cause water to bead and run off the lenses during downpours. You needn’t worry about the lenses fogging up in cold weather either. The same coatings will disperse any condensation very rapidly as my own testing verified.

I like the quality of both the rain guard and objective covers. Made from high quality rubber they fit snugly onto the instrument and provide excellent protection from the elements. The neck strap is of high quality – a good step up from the cheap generic designs you get with other models in the same price class.

In the hand, the instrument feels great. It’s grippy, robust and with a silky-smooth focus wheel, it’s very easy to engage with. Overall, the Zeiss is a very handsome binocular both to look at and to hold and seems to be robust enough to withstand anything nature is likely to throw at it. This is one place where I disagree with the reviewer in Preamble 2 above. Good job Zeiss!

Optics

Inspecting the interior of the binocular when trained on a bright torch light revealed excellent results. There were no internal reflections or diffused light around the light source, but I did detect a weak diffraction spike – a common artefact in roof prism binoculars in all price classes. This was much more subdued than in the 8x 25 pocket Terras I tested though. The spike is not intrusive on larger light sources but when I trained it on small light sources in the distance, I could see that little diffraction spike. Overall though these tests proved quite excellent and so will make a great instrument for studying cityscapes or surveillance at night.

Examining the exit pupils showed very good results too(see below). They are big, round and have very good darkening around the pupils indicating good blackening of the interior and effective baffling.

I was very pleasantly surprised when I looked through this binocular. The view is excellent; bright, very sharp, wonderful contrast but what impressed me above all was its exceptional glare control. Testing the instrument in all sorts of conditions from bright autumn sunshine, dull overcast, and wet drizzly conditions yielded uniformly excellent results. Many other binoculars in this $500 price class have ED glass, but this binocular taught me that not all ED glass is created equal. This Zeiss contains Schott ED glass and it really shows! Other instruments I’ve tested in this price class tend to show glare in low light conditions or when pointed toward a strongly backlit target, but this nifty little Terra stubbornly refused to show anything significant. This is one of the optical virtues that sends it right to the top of the pack in this price class in my opinion. This also explains the excellent contrast of the images garnered by this instrument. While I could detect a very slight yellow tinge against a whitewashed wall, it made the images warm, enhancing the beautiful colour of autumn leaves. Many lesser binoculars are ruined by glare and even though they serve up perfectly sharp images, their lesser contrast brings them down a notch or two in perceived sharpness.

Colour correction is excellent in this unit also. I could see none on axis and only a trace near the field stops even after testing it in very severe lighting conditions. The sweet spot is generously large. To my eye about 80 per cent of the field is very sharp with the last 20 per cent or so showing some softness. Pincushion distortion is very low and only manifests itself in the outer 20 per cent of the field. These low distortion images will be useful for studying architectural features.

Collimation was judged to be spot on as evidenced by how the binocular behaved under the stars. I also confirmed that the sweet spot extends to about 80 per cent of the distance to the field stops, with some field curvature and astigmatism morphing the stars significantly in the outer 20 per cent of the field. I also witnessed moderate illumination drop off when the Moon was moved from the centre of the field to the edges.

In summary, I was frequently reminded why Zeiss put their prestigious name behind this binocular. It has very high image quality and way above average resistance to glare of all types. I’m certain that it will delight the vast majority of people who look through it and therefore I’m in full agreement with the opinions garnered in Preamble 1 above. A thoroughly delightful visual experience!

Notes from the Field

The Zeiss Terra ED binocular is designed to operate flawlessly over a temperature range of -15 to +60C. In one test I left the instrument exposed to sub zero night temperatures for two hours(-3C), together with my Nikon EII 10 x 35. I can report that the focus wheel moved very easily and smoothly after this two hour exposure. In contrast, the Nikon focus wheel was much more sluggish and hard to turn until the grease had softened after warming up for a few minutes of it being brought back indoors.

Some of the more animated reviews I’ve seen, seem to be confusing a thin focal plane with depth of focus. Indeed, they seem to think that different binoculars offering the same magnification can show significant variations in focus depth but this is simply not the case. The main factor that determines focus depth is magnification – the lower the better. The super fast focus means that the focal plane is much thinner than found in a slower focuser taking say two or more revolutions to get from one end of its focus travel to the other. He also mentions the flat field of the Terra but I’m sure that’s just par for the course for a roof prism binocular. In another video, he compared a 10 x 42 Terra to a 10 x 42 Conquest HD and noted the Terra’s better colour correction.

The all but absent glare in the Zeiss Terra ED 8 x 42 makes it a particularly excellent instrument to use in dull overcast or low light conditions where colours become especially vivid. Browns and reds really pop in this glass! It was head and shoulders above and beyond my control 8 x 42s in this capacity. Views of the Moon are great: tack sharp, no glare or internal reflections and very little secondary spectrum within its sweet spot. Only at the edges of the field, did the Terra show some lateral colour but all within very acceptable levels. Is there anything I didn’t like about it? Well, yes; a small matter really. When I turned the instrument on a bright star field after dark, I noted how the brighter stars showed tiny diffraction spikes compared with my Porro prism binoculars, which produced perfectly round stellar seeing disks in comparison.  However, since I generally don’t star gaze with 8 x 42 roofs, this wasn’t an issue for me. The field of view of 7.1 degrees is also a little restricting, especially if you’re accustomed to enjoying expansive 7.5 or 8 degree fields. That said, I never felt ‘ tunnelled in’ while using it.

If you’re used to a slower focuser, the super fact focus wheel on the Terra 8 x 42 might take a bit of getting used to. But once you spend a few days in the field with the instrument, it becomes very easy and intuitive to use. Just a quarter turn brings targets from just a few metres away to several tens of metres away into perfect focus. This makes it particularly suited to high-intensity birding, and in this capacity, I enjoyed many moments following migrating Fieldfares and Redwings flit from the ground to the safety of trees in large groups. Sharpness at distance is also very noteworthy in the Zeiss Terra 8 x 42. I was able to pick off a tiny Goldfinch flying at a distance of 80 yards or so against a grey, overcast sky.

Conclusions & Recommendations

The Zeiss Terra ED 8 x 42 was a very pleasant surprise. It has an extremely well thought-through design and seems very robust and reliable. Optically, I rate it quite highly. The images it serves up are tack sharp with well above average colour correction, contrast and glare suppression. Has Zeiss succeeded in achieving ‘best in class’ status with the Terra line? From the tests I’ve carried out the answer appears to be a clear ‘yes.’ You’re not just getting a mid-tier binocular here, it’s a Zeiss binocular and you can tell that from the moment you bring it to your eyes.

Highly recommended!

My new book, Choosing & Using Binoculars: A Guide for Stargazers, Birders and Outdoor Enthusiasts hits the bookshelves in December and is also available for pre-order.

De Fideli.