masjah Posted January 15, 2016 Share #21 Posted January 15, 2016 Advertisement (gone after registration) Yes, the maximum aperture your eye can dilate to gets smaller with age. Through one's twenties, most people's eyes can get to 7mm, but you will lose about 1mm per decade after that. So a 50 year old man would typically have a maximum pupil diameter of around 5mm or so. Somewhere between 3 and 4 mm this effect of aging generally stops. To figure out what binocular's exit pupil is you simply take the size of the objective and divide it by the power. 7x50!binoculars have an exit pupil of 7mm. 8x32's have an exit pupil of 4mm. If the binocular's exit pupil is larger than your eye's entrance pupil, you are wasting some of the light your binocular's are gathering and could have bought something with a smaller objective and gotten the same result. That's why 8x32's for example, generally perform as well as 8x42's until it gets dark. Your pupils aren't dilated enough to use the extra light the 10x42's are collecting. Fornsomeone with a tremor, I'd recommend just trying out a few pairs to see if you can hold them steady enough. Lower power will probably be easier, e.g., 7x. Also, heavier binocular's may work better than lighter ones (within reason) since the extra mass may steady things down a bit. A spotting scope on a tripod, though, might be the ultimate solution. Thank you Jared, that is very helpful indeed. I think that my tremor on the one hand, and my 69 (rising 70) year old's pupil size has defined what size I need. I think this would be 8x32. My tremor defines the 8 as a realistic upper limit, and the 32 objective diameter then gives a 4mm exit pupil. Quote Link to post Share on other sites More sharing options...
Advertisement Posted January 15, 2016 Posted January 15, 2016 Hi masjah, Take a look here Leica ultravid HD 10x42 Binoculars. I'm sure you'll find what you were looking for!
Jared Posted January 15, 2016 Share #22 Posted January 15, 2016 You might want to try holding a set of 8x42's as well. Even though you would be wasting some light gathering, the extra mass might actually reduce the effects of the tremor. Worth double checking. - Jared 1 Quote Link to post Share on other sites More sharing options...
masjah Posted July 14, 2016 Share #23 Posted July 14, 2016 Well, my significant birthday arrived, and so did a pair of 8 x 32 Ultravid HD Plus, and very nice indeed they are too. Definitely the correct magnification and objective diameter for my needs. 1 Quote Link to post Share on other sites More sharing options...
Manoleica Posted July 14, 2016 Share #24 Posted July 14, 2016 Well, my significant birthday arrived, and so did a pair of 8 x 32 Ultravid HD Plus, and very nice indeed they are too. Definitely the correct magnification and objective diameter for my needs. Happy Birthday - Enjoy the Ultravids.. L 1 Quote Link to post Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.