Hi,
I'm wondering if there are folks who would like to discuss the perceptual aspects of binoculars and their use for birding. I'm finding that there are several misconceptions fueling debate that relate to apparent brightness, low-light effects, virtual images, apparent FOV, retinal projections, and so forth. Even in this day an age, several of the major companies are posting misleading information that should be better explained or eliminated.
Let me know if this appeals to anyone. Some information is on the Internet for very low-light astronomical observations, but oddly nothing I can find that pertains to problems of normal birding.
Thanks,
elkcub
[QUOTE=elkcub]Hi,
I'm wondering if there are folks who would like to discuss the perceptual aspects of binoculars and their use for birding.
...
Let me know if this appeals to anyone. Some information is on the Internet for very low-light astronomical observations, but oddly nothing I can find that pertains to problems of normal birding.
Thanks,
elkcub[/QUOTE]
Hi elkcub,
Yes, very interesting. I would like to start by asking, what actually is the "twilight factor" (=sqr(mag x objective diameter))? It is an easily calculated value, but in the light of what you previously told about the distribution and different sensitivities of the receptor cells in the retina, what exactly is 40% better in 16x50 binos than in 8x50s? And how the heck can this be proportional to the calculated value in human eye?
Thanks!
Ilkka
Hi Elkcub,
Near dusk or dawn the lighting changes quite fast so the advantage of "normal" birding binocular over another quickly goes away.
On a cloudy day, under a shady tree you may well have time to see the advantage of one binocular over another. What will be the size of your pupil when looking through the binocular? Aperture rules but can you use all the light being collected. Is the size of the target large enough to see well? Which binocular will give you the best combination of brightness, image scale and contrast?
What? You wanted answers? :-)
Rich