Keith, Before you commit to a pair of binocs, here are some considerations: 1. Clarity of image -- compare a hundred dollar pair of 8 or 9 power Nikons with a forty dollar pair of hardware store binocs. Sometimes money does not equate to better image quality. My current 8x23 Canon's (cost about $150 new) have poorer image quality than my old $100 8x23 Nikons. 2. Adjustment to fit differing corrections in your eyes -- I have a several-diopter-difference between my left eye and right eye, and many binocs can not bring both eyes into focus. [I am very near-sighted in the left eye and only slightly near-sighted in the right eye.] 3. Do you require eyeglasses? If you intend to wear them while using binocs, then you need binocs with fold-down eyecups. BTW, I find that the image quality is much better if I view directly, and the eyecups greatly reduce sideglare. Hence my need for a lot of correction -- per 2. above. 4. Waterproofness: mandatory if you use them out of your kayak. 5. Diameter of objective lens: those 6 x 30's will have __half__ the light-gathering power of a pair of 6 x 42's, at a relatively small increase in bulk and weight, although the 6 x 42's will cost substantially more.. 6. Power: anything over 7 power becomes problematic, most of the time if used from the bobbing confines of a cockpit. I used 8 power binocs for five years, and am backing off to 7 power ones this time around. This means an ideal unit for land-based birding (8 to 10 power is good) is not a good one for on-the-water viewing. 7. Age of your eyes. The older our eyes get, the less able they are to open the iris for good light gathering in dim conditions. This means the exit pupil diameter coming from a pair of binocs need not be as large for old eyes as it can be for younger eyes. [What's the exit pupil diameter? It is the diameter of the light cone exiting the rear of a pair of binocs. To get this number, divide the power into the diameter of the front (objective) lens.] Unfortunately, I don't know what the change is in iris opening with age -- maybe someone else on Paddlewise will. You can play around with different power binocs and figure out which ones work better for you. You want a unit with a large enough exit pupil to match your largest iris opening in dim light ... but anything larger is wasted. In bright light, your iris opening contracts quite a bit, so it will be fully covered by the exit pupil of almost any pair of binocs. HTH. -- Dave Kruger Astoria, OR *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************Received on Thu Mar 24 2005 - 07:57:52 PST
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