Canon image stabilized 10X30 Binoculars
by John Baars
Image stabilization in a Canon 10X30 IS II .
If you put binoculars on a tripod, you immediately notice that you see more details in the calm image than detached from the hand. At 6X or 7X magnification it is not so bad from the hand, that is still fairly calm. It is for this reason that many military binoculars usually have a magnification of 6X or 7X.
*1) Vubratovich, after empirical research, has even attached a formula to it :
Handheld efficiency/ mounted efficiency = 1 / ( 1 + 0.05 x magnification)
It follows that a 7X magnification on a tripod shows as much detail as a 10.5 X from the hand. Or a 10X on a tripod as much as a 15X from the hand. On an optical testcard linear resolution of the Canon 10X30 was 16.3” unstabilised and 11.8” stabilized. This is not realistic for double stars though. Linear resolution on a test card is always measured another way than angular resolution on point sources like stars.*2) A good 4 inch refractor will show you the Cassini Division, which is quite narrower than its theoretical double star limit. So for double stars roughly multiply with two. Albireo at 35” is rather easily resolved, even if handheld.
At 10X many observers reach the upper limit of holding their binoculars calm, above which it becomes necessary, especially for prolonged observation, to support the binoculars with elbows or with a tripod. At 12 or 15 times magnification, a tripod is generally recommended. There will undoubtedly be those who can hold their binoculars reasonably still for short periods at 15X, but not generally. The above numbers are experience data from observers over the hundreds of years that people have been using telescopes and binoculars. It is actually the greatest common denominator of individuals over the centuries.
Two types of movements affect the image in binoculars.
1. The relatively slow and large movements of the body; the movements we make to stay balanced. They are generally large, swinging up to 5 degrees in the field of view. With a frequency of 1-2 Herz. It is these movements that we can partially eliminate if we sit down when observing. This is usually largely successful. These coarse movements are less responsible for not seeing details than the second category. Our eyes ( brain) are able to still follow those slow movements.
2. The relatively small and fast movements are due to the twitching of the muscles in the hands, arms and neck. Muscle tensions, which prevent us from holding a binocular beautifully still. These are involuntary and we are not able to compensate for them consciously and fully adequate. Muscle tensions that become even greater the longer we try to hold on: fatigue and acidification of the muscles. Every observer knows the rest time he / she must take to "catch his / her breath". They occur in a frequency of 6-12 Hz and have a typical size of 0.25 degree. *3)
A sometimes-heard argument for using relatively heavy binoculars is that the higher mass of such binoculars attenuates vibrations due to their inertia. This is true, but fatigue occurs earlier, which in turn causes more violent vibrations. And an inevitable rest period. However, a very low weight again reduces the attenuation. A mass of 800 grams (1.8 lb) seems to be a reasonable compromise between the two extremes. All of this, of course, is highly dependent on strength, fitness and endurance of the observer.
It seems clear that lightweight, image-stabilized binocular have obvious advantages when observing in the case of a retiree like me. The 10X30 Canon IS II that I recently purchased weighs 640 grams (1.4 lb) including batteries , but the manual vibrations resulting from its lower weight are ironed out. The Canon does so with elegance.
Two oil-separated plan-parallel glass disks in the light path, encompassed by a flexible bellows and activated by electromagnets that can adjust the angle at which they are positioned with each other, many times per second, ensure that the image is adjusted. The magnets are controlled by a sensor. The Canon does this extremely quickly. The small vibrations of the hands (up to 0.5 degree in the image field) are processed so quickly that you no longer see them. According to researchers, the Canon electronic system does this perfectly at vibrations from 5 Herz and up.
You can still see the larger movements of the body ( 1-4 Hz), but experienced binocular observers are used to minimizing those anyway. In practice, you see those larger vibrations as a very light and slow "floating" of the image when you make such a large movement. So panning is just possible. When sitting well supported in a lazy garden chair, it is easily possible to generate a nearly dead still image for minutes at a time.
Some of my observations.
In ordinary daily life, I was able to read the time on a tower clock 6 miles away, although my watch was easier. The roof tiles and bricks on a farm 4 miles away. The joints in a building 1 mile away gave no problem. The bridge on ships 16 miles away. Aircraft identify to airline at 32,000 feet. Identifying geese at 2 miles. Individual feathers of a starling at 500 feet.... The small print on a lemonade can, the fine engraving in a small vase at 14 feet.
At night, the large open clusters of stars are especially breathtaking. Mel 2 in Perseus frame-filling, as are the Hyades. The Pleiades float before your eyes, in calm serenity, as does the Great Orion Nebula and the three belt- stars of Orion. M35 in Gemini and the three open clusters in Auriga, at least here in town, show up with ease as a small cloud of fog. The double open cluster in Perseus, a row of stars up to Stock 2, the Muscleman . A wonderful little trip to and from pure beauty. Sirius burns on the retina, with no annoying spikes...eye placement is not difficult.
M103 in Cassiopeia, NGC 457 Owl cluster (only the two brightest stars). Clearly recognizable. Of course, the 30mm objectives are not designed for small obscure nebulae. The large Andromeda nebula, on the other hand, allows for fine study. Also the Dumbbell-nebula M27 is visible, not the easiest from the city. M56 a lot more difficult. At M57 the Ring Nebula and the difficult globular M71 the small objectives here in the city only find their superior. Much easier are the globular clusters M13 in Hercules, M15 and M2. The little light spheres are unmistakably staring at you.
On the Solar system Jupiter was an obvious sphere, no banding or belts, his moons were visible too. Saturn as a lying egg, Titan was just out of reach. Venus as a 48” crescent in her final phase, Uranus if you know where to find him; many Moon craters on the terminator, mares stand out well. Quite a beauty.
All in all, the small binoculars give even a spoiled old observer like me more than enough satisfaction. At least enough to grab it every time it's a little bit clear between clouds and I slip outside. I marvel at the pleasure this little gem gives me every time.
Pro's and Cons
- The Stabilization! It REALLY shows a lot more than a regular handheld scope at the same magnification! An almost stationary image.
- It is light and can also be used on trips in nature. Short and long observation distances are no problem.
- Very calm image, sufficiently large 6 degrees, well clear, colorfast, even without stabilization, sharp and contrasty. Little scatter around bright stars and hardly or no false spikes and flares. Not even on Sirius.
- Flat image through the fieldflattener, stars at the edge are also stars and not ghosts. Pleasant.
- Easily adjustable, thumbs rest ergonomically in a recess. Grip is adequate enough.
- Light weight. 600 grams without and 640 grams with batteries. Battery life 9 hours at 20 degrees Celsius.
- Stars in the city to magnitude 9, which is good for a 30 mm. Because of large field of view excellent for open star clusters. When turning on stabilization it shows extra faint stars, very nice. Well suited for wide double stars. The exit pupil of 3 mm provides a pleasantly darker background sky than a 10X50 in the city.
- Spectacle wearers get the whole image.
- Without stabilization, this is an ordinary mid-range scope and not a top-end one. An average unstabilized 10X50 is heavier and therefore simply shows more detail than an unstabilized Canon 10X30 IS due to inertia. If you really want to get out what's in it you have to use the image stabilization.
- It is not waterproof. Shortest focusing distance 4.2 m, too long to get very close to insects, for example butterflies.
- On the Moon, a color edge is visible, not annoying, but it is there. Level of a good middle class bino without ED - glass.
- Body is lightweight plastic with a super-thin rubber jacket. It looks robust, but will not withstand a fall. Certainly not shockproof. I have not tested this out. Electronics and stabilization system are vulnerable. You need to take a little more care of it, they are certainly not throw-and-flick binoculars that can withstand anything. The rubber body coverage has a tendency to soften after a few years (sticking) according to some reviewers on various forums. An annual maintenance with talcum powder does not seem excessive. Objectives are very close to the surface and yet there is no protective cap included!
- Make sure you have two AA-batteries with you. Especially when you go out in the cold. There is no indicator on it.
- Only bright nebulae are visible, this is obviously not a deepsky giant on the somewhat smaller and fainter objects. For example, M57 the ringnebula was not seen from the city. M42 and M31 of course are.
- For this price you can also buy very good regular 8X30 bino’s. You pay for the electronics and the Image Stabilization.
1*) Yoder / Vubratovich, Fieldguide to Binoculars and Scopes, Washington 2011 ,
2*) Rutten and Venrooij, Telescope optics, Richmond 1988
*3) Holger Merlitz, Handferngläser, Verlag Europa Lehrmittel 2019,
- Philip S. Harrington, Touring the Universe through Binoculars, Wiley Science Editions 1990,
- Excellent review of a Canon 15 X 50 on this forum by Bigzmey
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