A Work Commenced March 5 2022

 

 

Preamble 

 

Product: GPO Passion ED 8 x 32

Country of Manufacture: China

Exit Pupil: 4mm

Eye Relief: 16mm

Dioptre Compensation: +/- 3

Chassis: Rubber armoured magnesium alloy

Field of View: 139m@1000m(8.0 angular degrees)

Close Focus: 2m advertised, 1.87m measured

Coatings: GPO Bright Fully Broadband Multicoated, dielectric and phase correction coatings.

ED Glass: Yes

Light Transmission: 90%

Waterproof: Yes

Nitrogen Purged: Yes

Tripod Mountable: Yes

Weight: 520g(advertised), 520g measured.

Dimensions: H/W: 11.8x 11.8cm

Accessories: instruction manual, cleaning cloth, hard case, neoprene neck strap, hard case strap, objective covers, ocular covers

Warranty: 10 years 

Price: UK £327.99

 

In previous blogs, I reviewed two excellent binoculars from the new company, German Precision Optics(GPO). The GPO Passion HD 10 x 42  proved to be a phenomenal performer, easily as good as the best models built by Zeiss, Leica or Swarovski. Indeed, someone sent me word that the guy who started Optica Exotica waxed lyrical about the larger 12.5 x 50 Passion HD, comparing it favourably to the flagship Zeiss Victory SF models, both in terms of build quality and optical quality. Unfortunately you’ll have to pay for the privilege of seeing that review.

The more economically priced GPO Passion ED 10 x 32 matched my personal requirements much more closely though, delivering both excellent optics and ergonomics in a much more portable package. Recently, I bought up its 8x sibling for an in-depth review: the Passion ED 8 x 32, which is actually available in four colour schemes. Initially I just wanted the same black colour as my 10 x 32, as I’m not especially partial to two-tone colour schemes, but after seeing the green & black model under different lighting conditions, I settled for the latter, as the photo above shows.

First Impressions & Ergonomics

Like the previous GPO binoculars I showcased, the little 8 x 32 arrived in the same beautifully designed presentation box. All of the accessories were to be found inside the high quality hard clamshell case with its attractive GPO logo. The binocular itself was immaculately presented, with its attractive dark green and black rubber armouring covering the tough magnesium alloy chassis. The long, slender barrels have ample room to wrap my fingers round, delivering an ultra-stable viewing experience.

The same top-quality anti-reflection coatings present on the 10 x 32 are also present on the 8x model. They present a lovely magenta hue in broad daylight.

One very neat feature of the objective lenses is that they are very deeply recessed inside the top of the barrels. This affords exceptional protection from rain, dust and stray light.

The magnesium alloy central hinge is short but very strong. It has nice tension, easily keeping your preferred inter pupillary distance (IPD) while being stored or in field use.

The eyecups are fashioned from machined aluminium, overlaid with soft rubber, and have three positions. The cups lock rigidly into place, with no wobble or wiggle room. These are among the finest eye cups I’ve personally experienced from any binocular manufacturer, period. Eye relief is a tad better than on the 10 x 32 model too, and I was able to image the full field of view with the eyecups fully retracted using my eye glasses.

The focuser is oversized and centrally located, taking just over one complete turn (~390 degrees) to go from one end of its focus travel to the other. Motions are very smooth and precise, with zero play when rotating it either clockwise or anti-clockwise. The level of tension is just right in my opinion, neither too fast or too slow, making it eminently suitable for birding, hunting or general nature studies.

The dioptre compensation ring is very sensibly located under the right ocular and is quite difficult to move. I noted the precise position it took for my right eye and was very impressed to see that it was adjusted to exactly the same position as on my 10 x 32. Neat!

The padded neoprene neck strap affords exceptional comfort when carrying the binocular around your neck. I choose to wear it high on my chest, to minimise the amount of swing the binocular undergoes while being carried.

The carry case and strap are of very high quality too. While there are similar cases offered by less expensive models, my experience with many of them is that the zipper breaks after a few months of use. Not so with this GPO clamshell case. I store the instrument with the eyecups fully extended, as shown below.

Optical Assessment

Having tested and enjoyed two other GPO binoculars, I was honestly expecting very good things from the 8 x 32 model. I began with my flashlight test, directing an intensely bright beam of white light into the binocular from across a room. I used the GPO Passion ED 10 x 32 as a control instrument in the same test. The result was very good. The beam showed no diffused light around the beam, indicating that the optical glass employed in the binocular was very homogenous. And just like the 10 x 32 ‘control’ binocular, there was no sign of annoying artefacts like diffraction spikes that can show up even in some high-end binoculars. I did detect a couple of very weak internal reflections in the 8 x 32 in comparison to the 10 x 32, but I deemed their presence largely non-injurious to the image. For example, when I turned the binocular on a bright sodium street lamp at night, those reflections were all but absent and neither were they apparent when I turned the binocular on a waxing crescent Moon. These results showed that the GPO Passion ED 8 x 32 can be used productively at night, for moon gazing and observing cityscapes from high-rise apartments, or monitoring harbour lights from an elevated vantage after dark.

In the next test, I examined the exit pupils as seen in front of an indoor lamp. The results(see below) were very encouraging: both entrance pupils showed no departments from circularity, and the area around each pupil was good and dark.

Right from the get go, I was taken by the quality of images served up by the GPO Passion ED 8 x 32, even during the dull overcast conditions on the afternoon the instrument arrived. The binocular serves up a very powerful optical wallop. Images snap to focus with no ambiguity across the vast majority of its impressively wide field. I would estimate the sweet spot to be about 85 per cent of the field of view, but falls off very gently as the field stops are approached. The remaining 15 per cent showed progressively more field curvature that younger eyes can accommodate to some degree(I have no trouble at 53), and some mild pincushion distortion near the field edges. Contrast is most excellent, with very good control of glare. Colours are vivid and true to form. Greens and browns are particularly well enhanced, especially as the late February-early March light faded in the evening. An overall light transmission of 90 per cent is very credible in my opinion.

I couldn’t detect chromatic aberration in the centre of the image. Viewing some denuded tree branches against a uniform, grey sky did throw up a trace of lateral colour from about 65 per cent of the way out from the centre, becoming a little more pronounced right at the edge of the field.

I took the liberty of capturing an image of a roof located some 35 metres in the distance with my IPhone 7 camera through the GPO Passion ED 8 x 32. It was taken with a 3 second delay and consists of a burst of ten images. No processing of any kind was done on the image. Although it certainly does not convey all the visual details, I think it does provide a fair indicator as to the quality of the field:

 

Depth of focus on the GPO Passion ED 8 x 32 is quite remarkable, in my opinion. Looking across an open field on a bright sunny day, I was able to view objects from about 50 metres all the way to infinity in wonderful, sharp focus, as if you were there. Examining the trunk of an old, dead tree trunk some 25 metres away, generated vivid three dimensional details of the moss, fungi and wood grain, as though I could reach out my hand and touch it! I believe this very immersive depth perception was particularly vivid owing to the excellent sharpness across the majority of the image, coupled to its enormous field of view(8 angular degrees). Close focus was significantly better than advertised too. I measured it at 1.87 metres; good news if you like to observe insects, flowers, water courses and rocks at close hand.

Ad Astra

Testing binoculars under the starry heaven is arguably the best way to assess aberrations and to check alignment of the barrels. That’s because it’s easy to get overwhelmed by a daytime vista in all its rich detail, and it can be difficult to judge where off-axis aberrations begin to encroach. Stars and other celestial objects are much simpler animals in comparison, and how they distort as one moves off axis is easier to diagnose. The first thing I did was to check collimation. This was easily achieved by placing the brilliant star Sirius in the centre of the field, while the binocular is mounted on a tripod. The Dog Star is close to the meridian after dark on early March evenings, and so is very well placed for testing. The star is focused as finely as possible and then the dioptre ring is turned to the end of its travel to create a prominent anulus of light. If the binocular is properly collimated the perfectly focused left barrel will be located on or inside the defocused anulus. If not, you’ve got an alignment problem. Such testing confirmed that the GPO Passion ED 8 x 32 was very accurately collimated, with the focused star being located just off the centre of the anulus. Good job GPO!

Centring the magnificent and sprawling Hyades star cluster, now sinking fast into the western sky, showed that all of the constituent stars were morphologically well presented in the binocular. Moving the bright, ochre tinted Aldebaran from the centre of the field towards the edge revealed that it remained sharp and acceptably well focused across ~ 90 per cent of the distance to the field stop, bloating moderately in the last ten per cent of the linear distance to the field. Much of this bloating could be removed by slight refocusing, indicating that the main culprit was mild field curvature. This tests showed that the little 8 x 32 will make a  fine star gazing instrument, as I was to discover after my formal testing ended.

In another test, I observed how well the glorious crescent Moon retained its brightness as it was moved from the centre towards the field stop. I detected very little in the way of brightness drop off, indicating that near full-field illumination was retained all the way to the edges of the field. I detected no visible chromatic aberration on axis but did detect a trace of secondary spectrum as it was moved to about 60 per cent of the way to the field stop. And even at the field stops secondary spectrum was still fairly modest.

It is also worthwhile tweaking the dioptre adjustment under the stars. I often find that adjusting the dioptre on a daytime target does not offer the very best correction. Usually, I obtain rough adjustment on a distant signpost, but quite often I find that when I examine the images of bright stars in both barrels, the dioptre compensation can be a wee bit off and can be micro-tweaked on a star image.

 Differences between the 8 x 32 and the 10 x 32 Models

Apart from the obvious differences in the sizes of the field of view served up by the 8x and 10x GPO Passion 32mm binoculars, two other disparities are noteworthy. Firstly, the diameters of the field lenses on the eyepieces of the 8 x 32 are significantly larger than the 10 x 32. The 8x glass has a 21mm diameter field lens compared with just 18mm on the 10x glass.

Intriguingly, I noticed that the larger ocular field lens in the GPO 8 x 32 ED induces some occasional blackouts(spherical aberration of the exit pupil) when first looking through the binocular, that are all but eliminated by paying more careful attention to obtaining the optimal IPD for my eyes. This is true irrespective of the fact that the 8 x 32 model has a larger exit pupil(4mm as opposed to 3.2mm on the 10 x 32). Despite its smaller field lens, I rarely, if ever, encounter blackouts with the 10 x 32. This result is also consistent with my previous blogs on the little Leica Ultravid BR 8 x 20(with its 2.5mm entrance pupil), where I reported little in the way of blackouts in field use, unlike some other reports I have read online. I believe this is attributed to the smaller ocular lenses on these binoculars, which forces one to centre one’s eyes more accurately from the start.

Secondly, there is a noticeable difference in the focus tension in the 10 x 32 compared with its 8x sibling. The latter has more tension than the former. I have found that this is actually a good thing going forward, as the 10x glass has a shallower depth of focus than the 8x, and so benefits somewhat from a faster focusing mechanism, especially  during glassing adventures in wooded areas.

Notes from the Field & Conclusions

During most glassing excursions, only a quarter of a turn of the focus wheel is used.  A gentle touch is all that’s required to focus more closely or farther away. One of the great virtues of this 32mm format is its light weight, tipping the scales at only 520g. That’s light enough to be used all day long. This format is also ideal for the vast majority of birding activities, which take place under good lighting conditions. As expected, the larger exit pupil on the 8 x 32 serves up a brighter image than the 10 x 32, but only when the light fades near and after sunset.

Trivia: did you know that the rain guard accompanying these binoculars can also fit over the objectives! Cool or what?!

During the first week of March, we enjoyed some cold but clear blue sky days, followed by dark, frosty nights. I enjoyed some mesmerising views of a waxing crescent Moon, with its beautiful earthshine illumining the dark face of our natural satellite.  But after the Moon set, I was able to enjoy some wonderful views of seasonal deep sky objects, such as the Pleaides, Hyades, the Alpha Persei Association and the Double Cluster. The super-wide and nearly flat field made observing these extended objects particularly pleasant. Fainter open clusters, such as M35 in Gemini, and the trio of Messier open clusters straddling the mid-section of  Auriga, were also very easy to sweep up in this small binocular.

Later in the night presented opportunities to observe the Beehive(M44) and Coma Clusters (Melotte 111). The excellent colour correction of the GPO Passion ED binocular presents stars in their natural hues, without any colour fringing. I particularly enjoyed glassing some showpiece binocular doubles in Leo, especially Zeta, Gamma and Alpha Leonis. This will make an excellent binocular to observe the full glory of the summer and autumn Milky Way later this year.

Birders will find the GPO Passion ED 8 x 32 to be particularly delightful to use. It’s very wide, sharp, immersive and glare-free field of view, together with its responsive focus wheel, renders it especially versatile in this regard. The superb ergonomic handling of the binocular in my medium sized hands adds yet another pleasant dimension to using this instrument. I feel that its rugged mechanical design and excellent optics will provide first-rate, hassle-free views for many years to come.

How can an instrument of this calibre be offered at such an attractive retail price? I think that’s probably down to the unique cross fertilisation of brains behind the company; founded as it was by professionals from across the leading European optics houses, who bring an eclectic mix of ideas to the table. This, together with the fact that their products are quality controlled in Germany before being shipped out to retailers, gives the consumer much greater confidence of obtaining a quality instrument that will stand the test of time. And that 10 year European warranty ensures that they will take care of your binocular should you hit any snags!

Is there any room for improvement? Yes, I think so! I would have loved to see hydrophobic coatings applied to the outer lenses, which would make it more resistant to the vicissitudes of our mercurial British climate. Since these coatings are now appearing on more economically priced models, I don’t think this is an impossible task for GPO to execute.

Right, that’s your lot folks!

Very highly recommended!

 

Dr Neil English is the author of seven books in amateur and professional astronomy. He hopes to announce some big news in the near future!

 

 

De Fideli.