I was reading some reviews of bins and was struck by the reviewer commenting that one 8x42 bin had "excellent depth of field" while another had "poor." Don't all 8x bins have similar focal planes, when focused at the same distance, as a function of magnification? They are less generous than 7x bins but more than 10x. Right?
Is there another factor besides magnification that controls for how deep the in-focus plane is and at what distance "infinity" focus is achieved?
Does the near focus distance have any functional relationship to this?
I am trying to figure out how 8x42 bins can differ on this. Perhaps one is really 7.5x and the other 8.25x or something?
Thanks,
Marc[/QUOTE]
I'm not a "serious optics person"
BUT:
Think of a camera objective. Changing the aperture affects the depth of field, doesn't it. I don't remember which way it works, but increasing/decreasing the aperture makes a difference. Photographers use this to get the desired effect in the photo.
This would imply that there is more to it than just magnification.
I know binoculars are not a camera, but maybe the same rules somehow apply?
Someone else might be able to clarify this?