Spotting scope - Business

please help improve this article by adding reliable references. unsourced material may be challenged and removed. (november 2007) an ornithologist using a . a is a small portable telescope with added optics to present an erect image, optimized for the observation of terrestrial objects. they are used for birdwatching and other naturalist activities, for hunting and marksmen, for surveillance, and for any other application that requires more magnification than a pair of binoculars, typically on the order of 20x to 60x. description the optical assembly of a typical s consists of a small refracting objective lens, an image erecting system that uses either image erecting relay lenses or prisms, and an eyepiece that is usually removable/interchangeable to give different magnifications. other telescope designs are also used such as schmidt and maksutov optical assemblies. they may also feature a ruggedised design, a convenient mounting for attaching to a tripod, and an ergonomic ally designed and located knob for focus control. marksmen assisted by a spotter using a . s are used on target ranges to avoid walking to the target to verify the placement of hits. eyepieces are usually interchangeable to give different magnifications, or may consist of a single variable "zoom" eyepiece to give a range of magnifications. magnifications of less than 20x are unusual, as are magnifications of more than 60x since it can lead to poorer image brightness, a narrow field of view, and show to much image shake, even on a tripod. the eyepiece mount layout can be "straight-through" (the eyepiece is on the same axis as the body of the scope), or "angled" (the eyepiece is at an angle of about 45 degrees to the body of the scope). the light-gathering power and resolution of a is determined by the diameter of the objective lens, typically between 55 and 80 mm. the larger the objective, the more massive (and expensive) the telescope, so size is usually fitted to the task b eing performed. a 100mm with a coaxial 30mm finderscope. manufacturers include: swarovski optik, leica, zeiss, kowa, nikon, pentax and vixen. references ^ porro prisms or roof prisms external links birding scopes ask-a-biologist - advanced briding guide - s wisegeek.com - what is a spotting scope? categories: telescopeshidden categories: articles needing additional references from november 2007 | all articles needing additional references

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