Celestron manufactures the Ultima line of Prismatic Spotting Scopes in 65mm, 80mm & 100mm varietals to suit your needs. The larger two can also be had with ED (extra-low dispersion) glass elements, an expensive product which produces a marked improvement in the color fidelity, resolution and edge delineation of the scope's imagery. All the Ultima line are mated to an eyepiece and render views which are both rightside up and laterally correct to the world, making them good for both terrestrial and celestial observing. All Ultimas are waterproof, making them more robust than ever before. Celestron surely is delivering exceptional value.
The Ultimas now offer the choice between 45° angled viewing or straight viewing as you prefer. Most users will prefer angled scopes because they are both simple to use for birds perched high above the viewer as well as easily simultaneously shared amongst users of differing heights. But some will prefer the straight viewing models, for these are much easier to use when hunting down the object of interest in the first place. Straight viewing models are also usually a bit lighter, brighter and less expensive. The choice is yours.
The Ultima 100 is amongst a handful of spotting scopes with an enormous objective lens diameter of 4", 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 viewfinder.
Certain Celestron products include their wonderful "No Fault" warranty coverage, which assures that your binoculars 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 Candadian citizens purchasing from an authorized Celestron dealer.