Comparing Two Wide field Constellation Binoculars- Orion 2x54mm versus Kasai 2.3x40mm

Comparing Two Wide field

Constellation Binoculars

Orion 2x54mm versus Kasai 2.3x40mm

I sat on the fence a few years before I decided to step off and gamble my money on these wide-field, low power Galilean binoculars. I've never been impressed with any sort of Galilean telescopes, field glasses or opera glasses and I suspected that they were just an expensive, trendy gimmick; but based on others' comments and experiences, I considered that these specialty items, with their wider than typical fields, might actually fill a niche in my astro-equipment arsenal.

In a nutshell, after trying them I found that yes, they do. I was truly surprised and impressed with how well a modern re-vamp of the Galilean system can perform.

Are they a replacement for my 7x35 wide fields, 8x42's or 12x50's?

Absolutely not! But they have their use and here's why:

I am a little bit near-sighted and have a small issue seeing at distance in low light conditions. In daylight my eyesight isn't bad enough to need correction according to the FAA medical examiner nor the driver license folks and I am perfectly happy with my uncorrected distance vision. But at night the stars are a little swollen and dimmer stars fade to invisibility. Therefore some amount of correction would be nice when looking at the night sky. I do not have nor want to deal with regular eyeglasses because the hassle/benefit ratio isn't worth it to me and I certainly won't deal with eyeglasses when using a telescope. But with their added magnification (though slight) these little binoculars tip the ratio in their favor. They provide that slight distance correction to sharpen up the stars with the added bonus of a magnitude boost which my aging eyes need. (My pupils don't dilate as much as they did when I was younger.) These little binocs allow me to see many more stars than my naked eyes (or eyeglasses) and many more satellites too! So that is the niche that these little Galilean field glasses fill, and they do it nicely.

The question remains, which of the three popular models is best for me? I chose to try two models which I considered to be the top end and the bottom end of the performance scale based simply upon the advertising literature. Here are the specifics of each:

WIDEBINO 2.3x40mm (28-degree advertised true field)

Kasai Trading Company, Tokyo, Japan. Cost: $155

This unit came in a very nice padded, nylon, zippered case. The eyepiece dust caps are fair. The objective dust caps fall off with a simple tap. I tossed them. I hate fumbling with binocular dust caps that aren't a single unit secured by the neck strap (like my Nikons have). The included nylon neck strap keeps the unit hanging with the objectives conveniently against the chest to keep them warm and dew free. The unit itself looks and feels to be of very good construction, with a solid dual center hinge. The individual focus eyepieces are smooth and easy to turn but it is also easy to accidentally defocus them. As they hang around the neck the eyepieces stick out pretty far and are the easiest parts of the unit to grab. Trying to grab them by the objective barrels usually results in bumping the eyepieces anyway, so I just hold them by the eyepieces. In daylight this isn't near the problem as when they are used on the night sky when focus is the most critical.

Eye placement is very critical for good focus. Setting the inter-pupillary distance accurately is a very necessary first step. Thankfully, the hinge is stiff enough to keep them where you set them. There is very little eye relief if you want to see the full field so I seriously doubt that anyone wearing eyeglasses could use these as effectively as those without. With my facial geometry, I need to sort of shove the rubber-covered eyepieces into my eye sockets to get a clear focus, therefore I was concerned about eyelash grease getting on the lenses, but the small eye lenses are recessed and fairly well protected by the eyepiece mechanical geometry. With extended use the eyelashes eventually win though. Cotton swabs and cleaner deal with that.

With my eyes under a moonlit sky and incomplete dark adaptation, they easily take in the entire hourglass of Hercules. They take in Bootes from the top of the ice cream (Nekkar) to the tip of the cone at Arcturus which is about 23 degrees. They can't quite make the stretch from Denebola to Regulus, but very close. They reveal many more stars than my eyes alone.

The literature mentions that the field of view increases with the diameter of the eyes' pupils. It is very easy to demonstrate this phenomenon by counting the visible slats of a nearby picket fence as day turns to dusk then turns to night. Considering that even in very dark conditions my almost 70-year-old pupils dilate to only 4.5mm, I'm very happy with the field of view rendered. By the way, the clear aperture of the eye lenses is about 8mm which will accommodate the advantage of younger eyes.

Orion 2x54mm Ultra-Wide Angle 36 Degree. China. Cost: $180

This unit also came in a very nice padded, nylon, zippered case. In fact it is identical in every way to the Kasai case. It seems extremely unlikely that they came from different factories. Even the included cleaning cloth is identical. The neck strap has more width at the neck than the one supplied with the Kasai and all four dust caps fit securely. This unit looks and feels to be of excellent quality construction. The inter-pupillary adjustment and the focus adjustments are much stiffer than the Kasai unit, but that is not a bad thing - at least in moderate temperatures. I did not put them in the freezer for a cold-weather lubricant test. Accidentally knocking them out of focus just doesn't happen.

These 54mm glasses are bulkier and heavier than the little 40mm Kasais, giving the hands a bit more to grasp. It is natural to grab the unit by the objective barrels. The eye lens aperture is a generous 18mm and I found that precise eye placement and inter-pupillary adjustment with this Orion unit isn't nearly as critical as with the Kasai unit. I don't have to scrunch the eyepieces into my eye sockets to see the majority of the field and I suspect that these may be much easier for the eyeglass wearer to take advantage of than the Kasai.

Interestingly, I can see the difference in magnification between the 2.3X Kasai and the 2X Orion. I didn't think 15% would be that noticeable. It is not significant but it is there and frankly, I prefer the slight extra power of the Kasai. The big difference between the units is the field of view which is very significant. The Orion trounces the Kasai in that regard. At dusk, the Orions are noticeably brighter too.

Even at dusk before complete dark adaptation, the Orion takes in Procyon and Castor (about 27 degrees) without breaking a sweat. The Kasai struggles to make it from Procyon to Pollux even after dark. In the dark, the Orions will not only reach from Denebola to Regulus but all the way to Subra. You get the whole Lion.

Another item I might mention: The Orions, with their wider view, at dusk can give an almost "fisheye lens" effect when panning up and down near the horizon. This may be an issue for those who tend to airsickness. However on the night sky with the absence of nearby terrestrial reference points there is no issue.

The Orion unit appears to have a little more attention paid to baffling, and the edge correction is vastly superior to the Kasai. Galilean telescopes certainly do not "snap" to focus, but the Orion unit comes closer to a snap than the Kasai unit, which is visually a bit mushier. In the dark, the Orions show stars to be pinpoints across most of the field. With the Kasais I find myself constantly fiddling with the Focus, trying to get any pinpoints at all - even at center.

I feel like if the Kasai unit were a telescope eyepiece, it would be a .965" from an old Asian import, whereas the Orion unit is more like a modern 1-1/4" or even a 2" eyepiece. Or perhaps the difference can be compared to the jump from a 60mm refractor to a 6" Newtonian.

Aesthetically, the Kasai has more of the "opera glass" feel to it, while the Orion has more of the "binocular" feel to it. The Kasai is the nicely upholstered, compact and maneuverable Volkswagen; the Orion has the raw power and positive response of the Highway Patrolman's Crown Victoria.

The Kasai is smaller, lighter, more ergonomic in some regards and frankly, more elegant than the Orion. The edges of the eyepieces are rubberized and the barrels have a tapered section that prevent them from pinching your nose even if set to a smaller inter-pupillary distance than mine which is fairly narrow - about 63mm. The Kasai's, I think, would work better for children whereas the Orions might not.

The Orions are claimed to accommodate an inter-pupillary distance of as little as 58mm, but that doesn't tell the whole story. Their eyepieces are shorter and the objective barrels are squared off and blocky at the point which, unfortunately, is right where the nose goes between them. When set to my 63mm distance they actually cause discomfort in use and prevent me from getting the eyepieces completely up to my eyes. In cold weather that cold metal is going to hurt! However, to spare the nose a bit of bruising and get the eyes a little closer it is possible to set the inter-pupillary distance just a bit wider than my 63mm because the generous 18mm eye lenses of the Orion product are very forgiving of this. In fact, they do pretty well for me when set to as much as 68 or 70mm. My nose certainly appreciates it!

It is very disappointing that the Orions are not tapered at that nose contact point like the Kasais are. It would certainly make them more enjoyable to use for those with narrow-set eyes and/or big nose bones. If you have both of those anatomical attributes, I recommend that you try them before you buy them!

So, which of these units do I like best?

Both! The Kasai unit is cute. Even though the Orion unit surpasses it in the clarity and field of view departments, the Kasai unit is lighter and smaller and fits comfortably about anywhere you want to put it, and it does a decent enough job on the night sky without pinching my nose. The 15% greater magnification is a plus. It was the first one I played with for a couple of weeks before the Orions showed up and it was my first love, convincing me that this kind of product is worth having around. But when compared to the Orion unit I think it will better serve as a sports glass, or perhaps a backup unit tucked into a corner of an eyepiece case. It works pretty well as a sort of terrestrial "night vision enhancer" around the yard too.

Which would I keep if I could only have one?

Sorry, Kasai. Performance trumps comfort under the night sky and the night sky is the whole point. Orion wins. I'll take the big block V8 over the whiney VW any day of the week, especially for only $25 more in cost. But your mileage may vary.

- NinePlanets