Greetings!
This may be an obvious question, and maybe it has been asked before... but I couldn't find anything on this forum addressing it so here goes:
From my understanding, lens coatings are applied to the lens surface to minimize the amount of light that is reflected upon hitting the glass surface, in order to attain the maximum transmission of light through the glass. Fully coated optics are now the standard for high quality binoculars... which got me thinking.
Why is the lens surface at the exit surface of the ocular coated? Since the light will be traveling from the glass directly to your eye at this point, it doesn't seem like there could be any light reflection at this point... it is all traveling in one direction (toward the eye). Why is this surface coated? Does it really help in any way, or is it actually hindering the performance by slightly restricting certain wavelengths of light (which almost all coatings do, from my understanding) ?
Best wishes,
Bawko
Probably because light is reflected at the glass to air interface as well as the air to glass interface.
Yes.
Even if that were not the case, a very important factor under most daylight situations would be the need to minimize stray light entering between the eye and the eyepiece lens from reflecting into your eye. For this reason, I also personally prefer eyepieces which have full multicoating rather than some more durable but also more reflective "hard coating" on the outermost surface.
I'm willing to take the extra care they might need.
Kimmo