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Message: <blockquote data-quote="kabsetz" data-source="post: 3307248" data-attributes="member: 10167">Ed,Thanks for linking the full Vukobratovich article. It really is excellent and contains a wealth of interesting information.The section on tremor in hand-held binoculars mentions Schober's measurements of hand tremble with the surprising (to me) finding that people belong to two distinct groups regarding the type of tremble they have. One group has three characteristic tremble frequencies centered between 1-2 Hz, 6-9 Hz, and 10-12 Hz with a sharp maximum between 7-9 Hz. The other group had either no distinct tremble frequencies or a flat maximum between 6-10 Hz. In the studied sample, the two groups of people were nearly equal size.If this is true, then we all belong into one of two types of tremblers, and may accordingly have different experiences of hand-held viewing. The type of trembler you are may also influence your experience with stabilized binoculars. I have tried to subjectively evaluate which type I may be, but cannot say that it would have been successful yet.In an article by Nolting and Kiesel, Verwackelt? Bestimmung der Sichtlinienstabilität stabilisierten Ferngläser (Fachhohschule Aalen), there are measurements that show the effect of IS on image shake with different stabilized binoculars. The Canon in this test, an 18x50 IS, damps less than half of the shake amplitude at under 3 Hz, but above about 4 Hz the damping is very good and consistent, keeping the shake amplitude consistently below 0.05 degrees. Fujinon is better between 2-3 Hz, but worse at all other frequencies. Zeiss 20x60 has significant damping of shake between 3-6 Hz, but not very much at other shake frequencies.It is quite possible that the widely varying experiences people report with image-stabilized binoculars are at least party attributable to viewers' different characteristic tremble frequencies and amplitudes. Testing this would be quite a task, and trying out for yourself is the easiest way to go. The other comment I'd like to make about Vukobratovich's article concerns the efficiency estimates. Based on my testing, I firmly believe that top-level modern binoculars when supported come significantly closer to their theoretical maximum efficiency than what was suggested in the article. Instead of an 8.8 efficiency rating for a 10x binocular, I'm quite sure the best ones get over 9.5 or 95% when well supported.Also, at least in my tests, with a hand-held but image-stablized Canon 10x42, I get well over 90% (about 95%) of the efficiency I get with the same binocular tripod-mounted. I don't know if I'm a particularly lucky trembler, but that is my mileage and the primary reason I'm such a strong advocate for image stabilization as an essential feature of hand-held binoculars.Kimmo</blockquote>

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