A Work Commenced November 29 2024
A few months back I bought in two of Canon’s Image stabilised binoculars: the 10 x 30 IS II and the 12 x 36 IS III for testing and evaluation. Having been suitably impressed with the smaller 8 x 20 model, I was keen to see how these larger units would perform. Of the two instruments tested, one emerged as a firm favourite- the 12 x36 IS III.
Both instruments have nice ergonomics. Focusing is precise and backlash free. These instruments focus by moving the objective lenses back and forth. The rubberised armouring affords excellent grip too. By storing these instruments in water-tight Tupperware containers with about 150g of silica gel desiccant, I was able to quickly render them fog proof. The interiors become bone dry after a few days of storage, allowing me to use them for extended periods in cold weather.
The 10 x 30 delivers crisp images from edge to edge. It is small and lightweight, and provides a good magnification boost at 10x in a 6 degree field. In a series of handheld tests against my 10 x 50 SRBC, the 10 x 30 IS II was easily shown to deliver finer details of critical targets at distance while the stabilisation button was engaged. Contrast is good as is resistance to glare. Examining the entrance pupils of both instruments shows well executed control of stray light as the photos below attest.
Both the 10 x 30 and 12x 36 exhibit modest chromatic aberration on high-contrast targets, with the 12 x 36 IS III exhibiting substantially more than the 10 x 30 unit. In contrast, the world-class optics on the 10 x 50 SRBC APO delivers virtually no colour fringing all the way across its enormous 7.5 degree ultra-flat field.
I noted no significant differences in the degree of stabilisation on both instruments, even though the 10 x 30 has a more generous range of stability at +/-1.0 degrees( as opposed to +/-0.9 degrees for the larger 12 x 36. I did note a slight defocusing of the image on both instruments as the stabilisation button began to be engaged, but a few moments later, they would settle down to give a nice, sharp image of various field targets. As well as seeing finer details than any handheld 10x binocular, I found I could tweak the focus post stabilisation ever so slightly to get the finest images these instruments can deliver.
I would recommend the 10 x 30 as a fine ultraportable platform for casual bird watching or nature studies. It’s also quite decent on the night sky but ultimately it proved to be inferior to the views garnered by the 12 x 36 ISIII.
I’ve been experimenting with various types of battery with these instruments. I found alkaline batteries to be troublesome to use on extended walks in cold weather when they would quickly discharge. I then switched to rechargeable lithium ion batteries. Despite warnings that they may overheat, I found them perfectly suitable for my purposes, delivering better cold weather performance in sub zero conditions, as well as longer lasting power delivery. I can also leave them inside the instruments while not in use without the worry of leakage and corrosion of the electrodes.
The 12 x 36IS III is an excellent, all-purpose instrument, delivering good daytime views. Weighing only a little more than the 10 x 30, it can be carried easily over miles of countryside. The extra magnification comes in real handy for identifying smaller birds at distance, though it struggles a little under dull winter light with its small(3mm) exit pupils.
What I absolutely love about the 12×36 ISIII is its astronomical performance. With the shorter days of autumn and winter, I’ve started night walks around Culcreuch Castle Estate, when I take along the 12 x 36 IS III to combine my love of stargazing with my enthusiasm for walking. In this capacity, the instrument gets regular use after dark. I have thoroughly enjoyed views of the showpiece glories of the night sky: with my eyes fully dark-adapted and away from village lights, I have soaked up magnificent views of the Pleiades, Hyades, the Double Cluster, the Alpha Persei Cluster, the Coathanger asterism and Kemble’s Cascade to name but a few. The 36mm objectives provide far more compelling views of fainter star clusters such as M36, M37 and M38 in Auriga than the smaller 10 x 30. M35 in Gemini and M34 in Perseus are well resolved. Collinder 70 is very impressively rendered, as is the Sword Handle of Orion. And while my 10 x 50 SRBC produces brighter images with more stellar sparkle, the smaller exit pupils of the 12 x 36IS III, serves up a darker hinterland, often producing more aesthetically pleasing views. Indeed the stabilised 12 x 36 shows me just as much as the larger 10 x 50 handheld.
Views of the Moon are excellent in the 12 x 36, with its 12 x delivering stunning views of maria and crater fields. Though some chromatic aberration is present, I don’t find it distracting. Jupiter shows a nice, clean, yellow-white disk. The Galilean satellites are well resolved once adequately placed away from the glare of the planet.
I’ve visited many binocular doubles with the 12 x 36 IS III. For example, Albireo is very nicely resolved handheld, the green and golden components showing up nicely. And just southeast of Vega, I was able to cleanly resolve Zeta Lyrae, the components of which are separated by 44 arc seconds with one component over a full magnitude brighter than the other. This is a challenge for a non-stabilised binocular but rendered easy using the stabilisation button on the 12 x 36 ISIII.
One final thing to mention: The Porro II optical design of these Canon IS binoculars render stars as very tightly focused and pinpointed, in contrast to what many roof prism binoculars serve up.
All in all, I’m thrilled to bits with the 12 x36 ISIII binocular. Any quibbles? Maybe just one: it’s less than stellar close focusing compared with many roof prism instruments I’ve enjoyed. It’s a small drawback for birding but not a deal breaker.
Read many more reviews of binoculars of all sizes in my book, Choosing and Using Binoculars: a Guide for Stargazers, Birders and Outdoor Enthusiasts.