HomeGlossary Field technique Playback Playing recorded calls or song to attract a bird into view. Use it sparingly or not at all. Never use it for threatened species, near nests, or where it is banned, including many parks. Field techniqueRelated termsFull glossary Spotting scope A portable telescope, usually 20–60x, used for distant birds such as shorebirds and waterfowl. Digiscoping Taking photographs or video through a spotting scope with a camera or phone. Exit pupil The width of the beam of light leaving binoculars: objective size divided by magnification. Field of view The width of the scene seen through binoculars, given in metres at 1,000 m or in degrees.
Spotting scope A portable telescope, usually 20–60x, used for distant birds such as shorebirds and waterfowl.
Exit pupil The width of the beam of light leaving binoculars: objective size divided by magnification.
Field of view The width of the scene seen through binoculars, given in metres at 1,000 m or in degrees.