Scopes utilize lens types alike to binoculars. Normal lens size variates from 50-80 mm. However, the main distinction among scopes is admitted to be the inner construction. Usually, two major design types are distinguished. Both kinds have pros and cons, and one should keep them in mind when choosing a device. The first one - straight - puts the lens on the same level with the focal point. This type of devices is used for tracing fast-moving targets, and is more comfortable for direct-line spotting, or viewing objects below your level. The second one - angled - is more comfortable when spotting an object in the sky (birds/stars/etc), and is more comfortable if using over a long period of time. You can buy scopes suitable for your specific needs for the lowest prices - only on MegaDepot.