by Jay Reynolds Freeman
About ten days ago I went by the Orion Telescope Center in Cupertino, California, and noticed a 25x100 binocular in their display of returned merchandise and seconds for sale. This model normally lists at $1149, but the returned unit was marked down to $749, which was very odd -- that's a big discount -- since I couldn't find a thing wrong with it. The sales person said he didn't know what the matter was, either, and the Orion folks have often pointed out problems in stuff on their returned-merchandise shelf, so I believe him. I had been wanting a larger binocular for a while, so when the unit passed all my usual tests and seemed entirely normal, I bought it.
A while later, I noticed a part rattling inside the binocular, that had evidently been wedged or stuck in place when I examined it before purchase. It proved to be the machine screw that holds the center-focus mechanism in place, so that the dual eyepiece assembly does not separate from the rest of the instrument when you turn the focus knob too far. I hadn't turned it far enough to spot the problem in the store. The loose screw was visible inside the hinge of the binocular, sliding back and forth, accessible from the front end of the hinge, through the tapped hole for the L-mount adapter. It took me five minutes to find my long, thin screwdriver, and thirty seconds to retighten the screw. No more rattling, and the eyepieces stay attached. I think I have a bargain.
A 25x100 is enormous. It weight 7.5 pounds ( about 3.4 Kg). I won't tell you I can't hand-hold it at all, but I will tell you that I cannot support it with only my bare hands well enough to do much. Yet I have always viewed binoculars as special-purpose instruments, whose virtues include ease of use and simplicity of setup, so I am reluctant to bother with a big, fancy mount for it. I will be experimenting with braces and supports in the near future, and will report.
I took my new toy up into the Peninsula hills one evening, and had first light while parked on the shoulder of the road. I was able to brace the instrument satisfactorily either on the top of my car door or on the rails of the roof luggage rack -- that's the kind of simple support I had in mind. I went through forty or fifty objects in as many minutes, mostly Messier catalog items. The performance offered a notable improvement over my 14x70; even at only 25x, many of the looser Messier globular clusters were beginning to look granular, and nebulous objects like M8, M16, M17, or M20 were beginning to show detail. For example, I could see both lobes of the Trifid Nebula, though I could not see the dark lanes that divide the larger lobe. Also, there was a wealth of dark nebulae visible in the summer Milky Way, though I had not brought any fancy charts with me, so I could not give names or catalog numbers to the ones I saw.
The binocular was unobtrusive optically. I didn't think to do a careful evaluation of its optical performance, because I didn't notice anything wrong with it in use. For a low-magnification unit such as this one, that is actually quite good testimony: The lenses don't get in the way of the view.
I expect to use this binocular a fair amount during the next few months; expect more reports.