Finding My Ideal Birding Binocular.

Starting well in 2022, with a leather-bound ledger and small, high-quality binocular.

A Work Commenced January 7 2022

Earlier in the winter, I tested my very first 10 x 32 compact binocular, a German Precision Optics (GPO) Passion ED 10 x 32. In that review, I began to explore its many virtues, including its great optics and ergonomics. In the weeks over Christmas and on into the new year, I’ve carried still more field tests and, as a result, have come to the conclusion that this particular instrument is to become my main birding binocular, relegating my smaller Leica Ultravid  8 x 20 BR to auxiliary roles, where extreme portability is a necessity, and also while conducting observations of my garden birdfeeders.

The GPO Passion ED 10 x 32 is the perfect form factor for my medium sized hands. I can wrap my fingers round the barrels to enjoy ultra-stable views of my avian targets. The optics on my unit are superb; bright, tack sharp and rich in colour contrast. The sweet spot is enormous, providing excellent, edge-to-edge sharpness across nearly the entire field. The 10x is preferred over the 8x because it provides greater image scale, especially at distance, but it’s excellent close focus (1.9m) is also very welcome for close up views of insects, rocks, fungi, water swirls, and for seeing leaf litter and the contours of tree trunks in glorious, high resolution detail.

I rate the optics on the GPO Passion ED 10 x 32 very highly indeed. It is easily sharper and better colour corrected than my Leica Trinovid HD 8 x 32, but costs only half its retail price. I consider it to be the optical equal to a Nikon Monarch HG 8x 30 I tested in the summer of 2021 but without those annoying blackouts and the rolling ball effect. Glare suppression on the little GPO Passion ED is also excellent. It never presents an issue in ordinary field use.

I reasoned that I would take some extra care of the eyepieces and objectives on the instrument, owing to their lack of hydrophobic coatings. In this capacity, I decided to upgrade the objective cover supplied with the instrument with better fitting Opticron-branded tethered objective caps, but still use the supplied rubber rain guard to minimise the amount of dirt and grime building up on the lenses.

I now have better fitting tethered objective covers for the GPO Passion ED 10 x 32.

The GPO Passion ED 10 x 32 has a very smooth and responsive focus wheel that is quite large in comparison to the overall size of the binocular. Because birding targets can move from just a few metres away to several tens of metres in just a few seconds, it’s important that the focus wheel can get from here to there as rapidly as possible. With just over one turn going from one end of its focus travel to the other, the GPO Passion ED 10 x 32  offers the perfect speed to execute those changes.

In my many dealings with many binoculars in the 30mm to 42mm size classes, I’ve come to the conclusion that 42mm is not at all necessary to obtain adequately bright images during the dullest of daylight conditions, even in the dead of winter. The highly efficient light transmission(90 per cent) makes up for the natural advantages of larger objectives too. Only in very low light conditions, such as occurs at dusk or dawn, or during star gazing, are the advantages of larger aperture binoculars abundantly in evidence.

My experiences with many binoculars sporting exit pupils of 4mm and higher, often left me tweaking the focus more than I was doing with high quality instruments with smaller(< 4mm) exit pupils. I became very conscious of myself constantly searching the image plane for tiny improvements in micro contrast and sharpness, my fingers working over time to achieve the absolute best focus in these instruments. I experienced none or substantially less of this ambiguity with small, high quality pocket binoculars like the Leica Trinovid BCAs or my current Ultravid 8 x 20, with exit pupils as small as 2.5mm. I reasoned that choosing a 10 x 32 over a 8 x 32  would allow me to get those same unambiguous focus positions, and I can now report that 3.2mm is a small enough exit pupil to replicate the same excellent results I’ve been getting with the Leica pocket binos. Why is a smaller exit pupil generating sharper images? I attribute it to the small exit pupil, which presents the best part of the human eye with a high quality imaging system – in the case, the GPO Passion ED binocular.

And yet a 3.2mm exit pupil is also large enough to transmit more light to the cones in my retina, producing noticeably richer colours under dull, daylight conditions. Comparing my 8 x 20 to my 10 x 32, it’s not hard to see that colours are significantly more vibrant in the latter. And this is an important parameter when trying to identify small, passerine birds in the distance.

Still one of the greatest advantages of going down from 42mm to 32mm is the substantial reduction in carrying weight. Typically, the downsizing amounts to losing up to 50 per cent of the weight of the binocular. For me, that’s a huge benefit as it’s not fun lugging a 42mm ‘brick’ round your neck over miles of difficult terrain.  Been there, done that!

No Slouch on the Stars Either

The time spent with the very nice Leica Trinovid HD 8 x 32 showed me that a smaller binocular like this can garner excellent images of the night sky, with enough light grasp to capture a large number of deep sky objects. But my experiences with the GPO 10 x 32 have been somewhat better. The 10x and almost flat 6 degree field is great for framing star clusters and familiar asterisms against a jet black sky. The smaller exit pupil on the GPO compact binocular presents the same aesthetic beauty of pinpoint stars that I have come to love in the smaller Leica Ultravid 8 x 20, only that the former’s resolution and light gathering power reels in a great deal more.

The GPO Passion ED 10 x 32 is an awesome instrument to watch the changing phases of the Moon. Even on cold January evenings, I’ve enjoyed seeing earthshine on the dark side of the Moon and beautifully sharp crater fields, mountain chains and ray craters. The 10 x 32 stubbornly refuses to throw up false colour on axis and even when the Moon is brought to the edge of the field does it manifest the merest trace of lateral secondary spectrum. Of course, the view is made even more compelling without the annoying internal reflections you get with lesser instruments. The sky immediately around the Moon is lovely and dark, allowing one to resolve quite faint stars very near its face. All these factors render the small 10 x 32 GPO  a very decent, lightweight sky-watching binocular.

The small but highly efficient light gathering capabilities of the GPO Passion ED 10 x 32 serves up surprisingly good views of the heavenly creation.

My ideal birding binocular not only has to have low mass and excellent optics, it must also have excellent build quality. The GPO Passion ED binoculars have a very robust build. And little things really matter to me. For example, the twist up eyecups must lock rigidly into position and stay there throughout glassing exercises. Indeed, I like to keep the eyecups up at all times, except when the instrument is stored away. That means that they have to be tough enough to allow me to attach the rain guard (untethered) on the cups while they’re fully extended. Many lesser binoculars fail in this regard, as they have a tendency to collapse when any pressure is applied to them; not so with the little GPO.  Those beautifully machined eye cups can withstand even the most forceful hand.

Eyecups you can just forget about.

What does that amount to?

Peace of mind!



To be continued……………………..


De Fideli.

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