Yes, when I sat down, which happens more frequently these days! I was looking at nearby flowers etc with a steady hand and rest, and it was impressive. Perhaps more importantly, my next pair of binoculars, I won't have to consider close focussing which will give me a better choice.
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Close Focus Anyone? (1 Viewer)
- Thread starter Tringa45
- Start date
Yes, when I sat down, which happens more frequently these days! I was looking at nearby flowers etc with a steady hand and rest, and it was impressive. Perhaps more importantly, my next pair of binoculars, I won't have to consider close focussing which will give me a better choice.
I keep experiencing that the close focus mentioned for binoculars is overstated for me. A 8x32 BA trinovid this afternoon, 3.3m, I got about 2m out of it. BN I had short about 1.5m vs stated 2.2m. Meostar 7x42 with 3m, I get under 2m, about 1.8m, MHG 8x42 1.6m vs 2m. So is close focus relative to visual acuity or something? How are the figures determined, a calculated average?
Alexis Powell
Natural history enthusiast
The spec of the bins might be a rough manufacturing average, but it is also true that if you have good accommodation (young eyes), you will be able to focus more closely through the combination of the binocular's close focus with your eyes' close focus ability. Even if you have old eyes, if you are myopic (near-sighted) and use bins without your corrective lenses, you will be able to focus more closely. Also, in bright light, your pupils may be small enough that the aberrations will be limited enough for appearance of better close focus than spec.
--AP
Yes, of course it depends on your individual eyesight and ability to accommodate.
Manufacturers' specifications would have to be an objective (no pun intended) measurement and I suspect it would be as follows:-
With the focusser at the extreme of its close focus travel, the minimum focus is the distance from an object to the objective lens in which its focussed image is at the focal point of the ocular.
That is rays from the focussed object woud emerge parallel from the oculars and would be at infinity (and thus most relaxing) for the normally sighted.
John
Thanks, that's about what I figured but missing the knowledge to make a sound worded theory out of it 3
So it's accommodation, not acuity. Gotta dive into the literature on optics and such. Intelligence lacking somewhat to wrap my head around it all. Glad I can also just grap some bins and enjoy the view :king:
The field microscope is good too.. only ~£30, plus you need some fairly small flat collecting pots that will fit underneath the stand. Makes micro moths on a par with macros I think is the best selling point / practical use I have for it. One or two more flowers etc may now be within my range for identifying!
