The Celestron Regal 100 F-ED Spotting Scope is a fully waterproof, armored device accepting any conventional 1.25" astronomy eyepiece, delivered with a zoom ocular. Celestron's been making premium scopes for awhile now, and the Regal F shows much in the way of evolution: the sunshade hood now telescopes and has a rotating sighting aid, the tripod collar now rotates as well, and they made the eyepieces interchangeable. The supplied eyepiece also features a T-threading just under the eyeguard; add a T-mount for your SLR camera and you can digiscope directly through the eyepiece.
But the Regal 100 F-ED's best improvement is that one of the objective elements now contains fluorite, a costly crystal material which goes a long way towards achieving true apochromatic color correction. Whenever light's harsh and contrasty, or when a colorful bird is cast against an overwhelming drab gray background, the fluorite will help define those edges of subject and background like no other element can.
For their flagship Regals, Celestron chose to only produce angled scopes. Angled scopes are much easier to share amongst a group of observers and are generally regarded as giving a more relaxed, comfortable observing position unless you're elevated more than 45° above a subject. It takes some experience to quickly locate subjects.
The Regal 100 F-ED is amongst a tiny handful of spotting scopes with an enormous objective lens diameter of 4.0", and as such is a large and weighty scope at that. But from dawn to dusk, and everything in between, you'll constantly be reminded of that objective lens size as everything you'll see will be that much brighter in the eyepiece. Digiscoping, as well, will be much easier thanks to all the added light reaching the inside of the camera.
Celestron's Regal spotting scopes include their wonderful "No Fault" warranty coverage, which assures that your scope will be repaired or replaced at Celestron's option for as long as you own them-no questions asked! The only requirements on the user's end are to ship the binoculars (at the user's cost) to Celestron with a proof of purchase and a check or money order for $25 to cover the costs of inspection, shipping and handling. This warranty service is valid only for USA and Canadian citizens.