
Originally Posted by
Bill Jobes
I've used both hoods 95% of the time, under the presumption that the huge chunk of glass is a 360° light magnet, and that the two-hooded isolation ensures that the sensor sees only what the lens is aimed at, and is not affected by any other light.
I also presume that Nikon engineers formulated it that way for good scientific design reasons. :)
On very rare occasions, mostly on dark cloudy days (with no precipitation), I've only used one hood, with no obviously negative impact on images.
I'd always use at least one hood, for light isolation and lens protection.