A Work Commenced September 23 2022

Product: GPO Passion 8 x 56

Country of Manufacture: China

Chassis: Rubber armoured magnesium alloy

Exit Pupil: 7mm

Eye Relief: 20mm

Field of View: 126m@1000m(7.35 angular degrees)

Close Focus: 2.3m advertised, 2.14m measured

Prism Type: Abbe-Koenig

Coatings: Fully broadband multi-coatings, phase correction coatings on Abbe Koenig prisms

Light Transmission: 92%

ED Glass: No

Waterproof: Yes

Nitrogen Purged: Yes

Weight: 1245g advertised, 1257g measured

Dimensions: 19.2 x 15.8 cm

Accessories: Instruction manual, cleaning cloth, hard, case, neoprene neck strap, hard case strap, objective covers, ocular covers and warranty card.

Warranty(European): 10 Years

Price: UK £589.00

In previous blogs, I reviewed some excellent quality binoculars from the new German-based company, German Precision Optics(GPO). In these reviews I was very impressed with the outstanding build quality of their products, not to mention their excellent optical quality. But GPO have not just settled on securing a solid niche in the compact and mid-sized binocular market, they have also developed larger aperture models specifically designed for low light work and astronomy; enter the GPO Passion 8 x 56 and 10 x 56 series.

I acquired a 8 x 56 unit on loan from Steve at First Light Optics for testing and evaluation, and I must again say how delighted I was to see that GPO really are delivering excellent value for money in this competitive corner of the sports optics market.

The instrument arrived in a beautiful presentation box, as shown in the photo above. The binocular was set rigidly in place in the cut-out foam section and lying adjacent to it, the beautifully designed hard case to store the instrument. Inside the case you’ll find the usual accessories; padded neoprene logoed neck strap, carrying strap for the case, a comprehensive multi-language instruction manual and microfibre lens cleaning cloth. If you take the case out, you’ll also find the 10-year European warranty card for the instrument.

Ergonomics

The GPO Passion 8 x 56 is one chunky instrument and you immediately get the feeling of quality the second you prize it from the box. This larger instrument is a scaled up version of the 42mm and 32mm Passion ED binoculars, with a magnesium alloy chassis overlaid by a nicely textured black rubber armouring.

Tipping the scales at 1257g, this is not an instrument that many would happily trek with all day long; unless you’re Hulk Hogan.

It’s designed to be used for short hand-held viewing but mostly for tripod mounted activities, such as hunting in low light or watching the stars The focus wheel is covered in a textured black rubber which is easy to grip, rotating just over one full revolution anti-clockwise from nearest focus to just beyond infinity. Though I have reported a small amount of free play in a smaller 10 x 32 GPO Passion ED in a previous review, I was pleased to see that there was none apparent on the focus wheel of this 8 x 56 model.

A closer inspection of the shape of the barrels betrays the nature of the prisms used in this binocular; the large Abbe-Koenig roof prisms that deliver higher levels of light than standard Schmidt-Pechan prisms incorporated into the smaller GPO models. It’s these Abbe-Koenig prisms that contribute to the weight and the length of this binocular, but it’s all the more remarkable that this optical design is incorporated into this low light binocular at this price point. These prisms are notoriously difficult to make well and are usually only found in instruments costing at least twice as much as this 8 x 56 costs.

The beautifully machined twist-up aluminium eye cups are covered in soft rubber for very comfortable viewing. Four positions are offered to suit most anyone’s requirement for eye relief. I’ve said it before and I’ll say it again: these are amongst the best eye cups ever designed by any binocular manufacturer, period. I was easily able to access the entire field of view with eyeglasses, so absolutely no worries there. The dioptre adjustment is accessed by turning a ring under the right ocular. It moves smoothly but with considerable tension, ensuring it won’t easily be moved out of position in field use.

The proprietary broadband multi-coatings present with a fetching purple hue in broad daylight and are immaculately applied. Viewed head on, they make the lenses almost disappear. The instrument is dry nitrogen purged internally and o ring sealed to prevent fogging up of the internalized optics. It’ s also waterproof, but GPO don’t mention to what degree it will withstand water immersion.

The reader may be surprised to learn that, unlike the smaller ED models, the larger 8x and 10 x 56 models do not contain ED glass. GPO believe it wasn’t necessary to incorporate extra low dispersion glass in these models because their main use was in low light conditions, when seeing any colour in a given target becomes difficult to discern, so there would be little advantage in employing an ED element which would have significantly increased its production cost. Having enjoyed many hours testing the instrument both in low light situations and under the stars at night, I can only agree with their design philosophy, as I shall report on a little later. All in all, the build quality and ergonomics of this 8 x 56 are exemplary, and quite in keeping with the other models I’ve reviewed from both their ED and HD lines in the past.

Optical Testing

My first optical test involved shining a bright light source into the binocular and examining the images produced. I detected a few minor reflections but nothing too intrusive. Diffraction spikes were very subdued and there was very little in the way of diffused light around the light source, indicative of good, homogenous glass. Turning the binocular on a bright streetlamp after dark did show a few minor internal reflections as I anticipated, but by and large I was quite happy with the result. Placing the lamp just outside the field of view showed very little in the way of stray light intrusion; an impressive result compared with many other similar tests performed on other binoculars.

Examining the exit pupils also yielded good results, as shown below. The large 7mm exit pupils were perfectly round with little in the way of extraneous light around them. I did pick up some light leaks well away from the pupils though, a consequence of using Abbe Koenig prisms perhaps? Thankfully they appeared to make no material difference to the images garnered by the instrument, in daylight at least.

Testing the binocular out on a bright, sunny afternoon revealed very impressive images right from the get-go. The view is razor sharp inside its very large sweet spot, with only a small amount of softening of the images noted near the field stops. Contrast is excellent.  Scanning a large swathe of trees at the edge of a forest proved to be a very comfortable experience and extremely easy on the eyes, with no blackouts or the rolling ball effect, kept under control courtesy of a modest amount of pincushion distortion near the field stops. Colours are very vibrant in this big glass and I immediately noted the warm tone of the images – very much like those I reported on the smaller ED and HD models. Indeed, I had long wondered whether this warm colour tone was a manifestation of the ED glass utilised in the smaller GPO binoculars or just from the coatings used. I now think it has more to do with the latter than the former.

Glare suppression is excellent in the GPO Passion 8 x 56. It stubbornly refused to show any on bright autumnal days, and also on grey overcast days in the open air. Veiling glare was also exceptionally well suppressed in this instrument too; a testament to the excellent coatings applied to the lenses and prisms, as well as the baffling used throughout the optical train. Close focus was also very surprising. I measured it at just 2.14m, so slightly better than the advertised 2.3m. I consider that amazing for such a large glass!  Chromatic aberration was also very well controlled in this unit. There is a small amount visible on high contrast targets, such as imaging the side of a telephone pole against a bright overcast sky. Lateral (off axis) colour is a bit more pronounced in this large aperture instrument though, as I openly expected, but I felt it was perfectly acceptable given the modest price tag of this instrument. Overall, I would rate the daytime images as quite excellent.

Testing its low light capability, I compared and contrasted it with the views through my excellent Opticron Imagic TGA WP 10 x 50 Porro prism binocular. I found the views very comparable until about a half hour before sunset on September evenings, with the 8 x 56 pulling noticeably ahead on selected targets under poorly illuminated hedgerows as the last rays of sunlight dipped below the horizon. By about a 40 minutes after sunset, the 10 x 50 was really struggling in comparison with the 8 x 56.

Under the Stars

I was dying to find out how the GPO Passion 8 x 56 would perform under a dark, clear sky at night, and I wasn’t disappointed here also! In fact, the views were absolutely stunning! The very generous field of view effortlessly frames wonderful star fields. Bright stars such as Vega and Aldebaran are rendered in their natural colours. Chromatic aberration was a non-issue in the inner 50 per cent of the field, and only showing mild splashes of bluish purple as the stars were moved to the outer part of the impressively large field of view. Fainter stars were examined to see how well they maintained their pinpoint sharpness. I was very pleased to see that they remained impressively small and tight across about 75 per cent of the field, with some mild field curvature beginning to show up thereafter. Only in the last 10 per cent of the viewing portal, could I make out  a small amount of astigmatism and coma creeping in.

I was genuinely surprised how long I could hand hold the binocular while scanning the Milky Way through Cygnus, Perseus and Cassiopeia. The low power of 8x definitely helps in this regard. For more serious studies though, I resorted to mounting the instrument on a light weight monopod. Views of the Pleiades and Hyades in Taurus were simply stunning, its impressively high light throughput presenting very faint stars quite invisible to a 42mm model. In fact, this instrument threw up some of the best binocular views of the heavens I have personally experienced. I enjoyed exploring many early autumn open clusters, such as the M36, 37 and 38 spanning the mid-section of Auriga. M 34 in Perseus and the great globular cluster in Hercules (M13) in this large binocular light bucket. Mighty Jupiter, now prominent in our night skies, was dazzlingly bright, with its four giant moons being easily seen. Fiery red Mars was also stunningly presented in Taurus against a jet black sky.  The Alpha Persei Association and Double Cluster in Perseus were breath-taking in this binocular too. Rising up in the wee small hours of late September, I was treated to some extraordinary views of Orion; with the white and blue-white Belt stars shining brilliantly, and below them, the famous Sword Handle of the celestial Hunter, with the magnificent Orion Nebula blazing forth across the light years. The excellent light gathering power of the GPO 8 x 56 allowed me to follow much fainter tendrils of nebulosity than I could make out in a optically excellent 7x 50 Porro prism binocular, though I must concede to yearning at times for a look through its higher power sibling; the 10 x 56, which probably would have totally blown me away lol. All of these experiences only consolidated what I had seen during the day: this is an excellent low light/astronomy binocular that would satisfy the most discriminating of observers.

So, here we have yet another GPO binocular offering exceptional ergonomics and really good optics for a very decent price. I say this in light of a cursory examination of other 8x or 10 x 56 models, built around Abbe-Koenig prisms. The Zeiss Conquest HD 8 x 56, for example, has a build quality quite comparable to the GPO Passion, but its field of view is slightly smaller(125m@1000m), its weight slightly heavier(1265g),  its eye relief lower(18mm), its close focus distance much longer(3.5m), and possesses a light transmission of 90 per cent, lower than that of the GPO Passion, even with ED glass. But that instrument retails for more than twice the price of the big GPO light bucket! Or consider the fluorite containing Maven B5 10 x 56 costing a few hundred pounds more than even the Zeiss Conquest HD but with the same light transmission as the GPO Passion(92 per cent or so). Seen in this light, the GPO Passion 8 x 56 offers tremendous bang for buck and absolutely deserves great success in the burgeoning sports optics market.

Highly Recommended!

Dr Neil English explores many more hot bargains in his up-and-coming book, Choosing & Using Binoculars: A Guide for Stargazers, Birders and Nature Enthusiasts, due out in late 2023. 

My sincere thanks to Steve at First Light Optics for kindly lending me the instrument for field testing.

De Fideli.