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Message: <blockquote data-quote="kabsetz" data-source="post: 1329516" data-attributes="member: 10167">A couple of comments,First, on the issue of closing one's eye or using an eye-patch when using a scope. It is true that squinting is uncomfortable, and that using a dark eye-patch induces unwanted dark-adaption which makes switching back and forth with a binocular awkward and uncomfortable. A solution I have found to work very well for me is an adaptation of what many sharp-shooters use, i.e. a visual obstruction placed in the field of view of the unused eye. Shooters usually have a small piece of either dark or opaque plastic attached on a short arm on some kind of a head-mount or the rim of their glasses if they use them, but that is awkward when birding. On my previous scope, I fashioned a screen out of a binocular objective cover (ca. 60mm in diameter) which I mounted on the eyepiece with some stiff but bendable single-conductor copper wire. In my present scope, I use the s.o.c. eyepiece hood, which I have turned inside-out to have the black lining be the visible side. I simply velcro it with its regular fastener tabs so that it points straight to the side, and it conveniently intercepts the central line of vision for my idle eye. That is all that it takes so that the visual information from the idle eye is basically ignored by my brain, and since enough stray light enters the idle eye, no accommodation problems result.The other comment concerns large-magnification binoculars, IS binoculars and effects of hand-holding vis-a-vis tripod-mounting. I'll paste below an excerpt of the test I wrote for Alula in 2001 on the Canon 15x50 IS. We did some interesting (well, to me anyway) tests with a few reference binoculars. The whole test can be found at: <a href="http://www.alula.fi" target="_blank">www.alula.fi</a> if you go to the English pages, and towards the bottom of the page can manage to find the link to published reviews of optics."Image sharpness was tested with the bank note test explained in ALULA 4/2000, but this time it was conducted indoors in order to more easily control light levels and to avoid atmospheric disturbances. Leica 8x32, Nikon SE 10x42 and Zeiss 15x60 served as reference binoculars, and at the first stage all binoculars were tripod-mounted with the Canon's stabilization turned off. The following resolution distances were obtained as an average for two testers: Leica 4.56, Nikon 5.72 and Canon and Zeiss both 8.47 meters. Within likely margins of error, these results correspond to the ratios of magnifications for these binoculars. In other words, with the Canons as well as with the other binoculars, we can speculate that the limiting factor was the visual acuity of the testers (both of whom have well above average vision), as of course should be the case with top-quality optics. With the Canons hand held with stabilization engaged, the result was 8.22 meters, or 97% of the tripod mounted result. Hand held results of the Zeiss and Canon (now without stabilization engaged) averaged 7.5 meters, Nikon's about 4.6 and Leica's about 3.5 meters. What is surprising about these hand-held results is that when the ratio of magnifications is taken into account, the results were better for the larger magnifications, not worse as conventional wisdom would suggest. However, even very brief glimpses of the barring in the test target were counted as a resolved target, and it is possible that the larger mass of the bigger binoculars gave them an advantage here. Whatever the case, subjective factors are more pronounced in hand-held testing. To further test the performance of the stabilizer, an experiment was conducted outdoors (Helsinki, March 27, 7.45-8.00 p.m., sun had just set, clear skies) where the Canon was compared with the Leica 8x32 in reading a leg band of a Herring Gull (white C, #C5S26). We measured the distance at which we could with certainty read the number 5 and the letter S, which were easily confused. With the Leica, the average of the distances obtained by two testers was 20.5 meters and with the Canon 44.9 meters. To summarize, the above results indicate that with the stabilized Canon one can resolve detail at 1.8-2.3 times farther than with hand held conventional 8-10x binoculars. In addition, the stable image gives the viewer more time to analyze what is seen, meaning that in real-life bird identification situations the advantage might be even greater."Kimmo</blockquote>

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