A Work Commenced October 30 2022
Product: GPO Passion ED 8 x 42
Country of Manufacture: China
Field of View: 143m@1000m(8.1 angular degrees)
Exit Pupil: 5.25mm
Eye Relief: 17mm
Close focus: 2m advertised, 1.95m measured
Coatings: GPO Proprietary broadband multi-coatings, dielectric coatings on Schmidt-Pechan roof prisms, Hydrophobic coatings on objective lenses
Light Transmission: 90%
ED Glass: Yes
Nitrogen Purging: Yes
Tripod Mountable: Yes
Weight: 740g advertised, 743g measured
Accessories: Custom GPO hard clamshell case with strap, wide neoprene logoed neck strap, microfibre cloth, ocular and objective covers, instruction manual, warranty card
Warranty(European): 10 Years
I’ve already covered two compact binoculars from German Precision Optics(GPO) in previous reviews, but readers may be interested to know that they also manufacture a number of full-size binoculars in the 8x and 10 x 42 format. GPO say their Passion ED binoculars are their ‘entry-level premium’ line of high-performance instruments Just like the smaller 32mm models, these full-size binoculars come in a choice of colours: sand, brown, black and green. I ordered up the 8 x 42 Passion ED – in an eye-catching sand coloured chassis – on loan from First Light Optics for testing and evaluation.
GPO really go to great lengths to make the initial unboxing experience as pleasurable as possible. And sure enough, I received the attractive black presentation box containing the instrument and its accessories. The binocular was presented on one side of the box, snugly positioned in the cut-out foam. The grey clam shell hard case was sat next to it, containing all the usual high-quality accessories including a wide neoprene neck strap with the GPO logo sewn in, ocular and objective covers, a micro-fibre lens cleaning cloth, a strong carrying strap for the case, a small instruction manual and a 10-year warranty card. As a point of interest, GPO USA offer their models with a lifetime warranty; good to know if you’re planning to purchase one in the States.
As I’ve come to expect, the instrument exudes quality from top to toe, with its sturdy magnesium alloy chassis covered by a thin covering of textured rubber. Like the 32mm models, the bridge is quite narrow, providing additional space to wrap your hands around. The instrument is very small and compact for a full-size binocular. Tipping the scales at 743g without the strap, the instrument features fully multicoated optics using GPO’s proprietary coatings, an ED glass element to reduce colour fringing and a fast focus wheel to quickly engage with your targets. The instrument feels fantastic in the hands. The GPO objectives are very deeply recessed, affording extra protection from stray light and the vagaries of the elements. I detected little or no internal reflections or significant diffraction spikes in my torch test. Just like all their product range, the GPO Passion ED eyecups are excellent and amongst the best in the industry. There’s no plastic anywhere to be seen on these cups. They are made of machined aluminium, overlaid with a soft rubber substrate affording very comfortable views, even after prolonged use in the field. Four positions in all are offered, from fully extended to fully retracted. The focus wheel takes about 1.5 revolutions anti-clockwise from closest focus to infinity and a little beyond.
Optically, the GPO Passion ED 8 x 42 offers an excellent image; wide(8.1 degrees), bright and full of rich contrast. Colours really pop in this instrument and glare is very well controlled as my field tests showed, both in bright sunny conditions and on dull, overcast afternoons. GPO claim a light transmission of 90 per cent across most of the visual spectrum, and this is quite believable from the images it serves up. But you don’t have to take my word for it! The Dutch optical physicist, Dr Gijs van Ginkel actually performed independent spectrophotometric measurements on the smaller 32mm Passion ED models, where he was able to verify light transmissions of just over 90 per cent in the middle of the spectral range of the human eye.
A Curious Aside
Before moving on from the subject of colour correction and ED glass, I would briefly like to take a moment to clarify something I’ve heard again and again from reading binocular reviews carried out by magazine authors. For example, in the November 2022 issue of a popular UK birding magazine I read the following statement:
“The ED glass ought to give great light gathering and transmission among other things….”
This is a misleading statement. Extra low Dispersion(ED) glass does not increase light transmission. Its main job is to increase contrast and image sharpness when mated properly with additional elements. In a complex optical system such as a modern roof prism binocular, the brightness of the image is attributed to the number of optical elements employed, the homogeneity of the glass(fluorite crystal, for example, has very high homogeneity and thus has impressive light transmission) and the quality of the coatings used throughout the optical train. Here is a good example of what I’m talking about. In these examples, the non-ED binocular has a measured light transmission that is greater than another binocular with ED glass.
The large 5.25mm exit pupil makes eye placement easy, though I did encounter a few blackouts from time to time. Careful eye placement is needed to ameliorate the worst of this. The 17mm eye relief is more than adequate for most users, though some will undoubtedly find this a bit tight. The sweet spot is very large – ~70 per cent of the field -after which mainly field curvature and a small amount of astigmatism softens the image. Overall, the views are delightful, immersive and engaging; exactly what you’d expect from a high-performance binocular like this.
The exit pupils are perfectly circular and well blackened in their immediate vicinity, as the photos below reveal:
Notes from the Field
I enjoyed a spot of Jay watching in bright autumnal sunlight, where I was impressed by the sharpness of this binocular. The excellent contrast and colour correction, as well as the wide angle of view of the 8 x 42 Passion ED made it very easy to pick off their colourful plumage, as they flitted from oak tree to oak tree in search of acorns, their staple. Even when caught gliding against a bright sky, I could make out very little, if any, chromatic aberration. A splash or two does show up as targets are moved off axis though, but that’s all par for the course in most binoculars costing up to and well beyond £1000. Indeed, I’ve never looked through a binocular that doesn’t show some trace of colour fringing. Such is the nature of refractive optics!
In a previous review of the smaller 32mm ED model, I suggested that one improvement GPO could make to their Passion ED line was to add a hydrophobic coating to the outer lenses which would enhance their performance in adverse weather conditions. I was delighted to read on the First Light Optics website that they had apparently responded to this. “Trust but verify” is a maxim I have subscribed to all my life, so I tested GPO’s claim. Breathing on the objective lenses on a cool afternoon outside, I was impressed by how fast the condensation vanished in comparison to an untreated ‘control’ objective lens of the same size. This will make the GPO Passion ED binoculars even more versatile when using them in cold weather. Afterall, there is nothing more frustrating than having your view ruined by accidental fogging, especially when engaging something interesting in the field of view. Good job GPO!
I also enjoyed some stargazing adventures with this binocular. It’s very wide and well corrected field of view makes sweeping the heavens a real pleasure in this full-size binocular. Stars are presented in their true colours and many of the show piece objects of the sky are within reach of this quality 42mm aperture glass. In general, I prefer 10x for stargazing, but the excellent light grasp and lower power of 8x makes the views more steady and easier to enjoy during prolonged vigils. You needn’t worry about internal fogging either; these binoculars are waterproof to 1m depth and are dry nitrogen purged. Close focus is a very respectable 1.95m, so fine for close up work too.
If I’m being honest, I was a little anxious about whether I’d receive a unit with some play in the focus wheel. This is something I’ve heard from a number of users of GPO binoculars, at least in the early days. To my great relief, the focus wheel was really fine; buttery smooth and totally backlash free. Clearly GPO has addressed this issue in house, which is great news, as I’m not alone in absolutely detesting any play in my binocular focusers.
The 8 x 42 Passion ED is an excellent birding binocular, with its very wide and well corrected field. Colours are vivid and true to life. Seeing the extremely fine vermiculations on a Greylag goose that had happened to rest for a few hours on my local pond one bright September afternoon was a particularly delightful experience. You’ll never mix up a Magpie and Greater Spotted Woodpecker half a mile away with these binoculars!
In summary, this is an excellent general-purpose binocular, exemplifying many of the virtues of mid-sized field glasses. It really does everything very well indeed, and in many circumstances greatly exceeds one’s expectations.
I would like to thank Steve at First Light Optics for kindly providing the GPO Passion ED 8 x 42 for review.
Dr Neil English is the author of seven books in amateur and professional astronomy. His 8th title, Choosing & Using Binoculars: A Guide for Stargazers, Birders and Nature enthusiasts will be published by Springer Nature in late 2023.