Tele Vue Optics Article Page

The eyepiece calculator reveals the observing potential of your telescope with Tele Vue Optics eyepieces.

It accepts basic information about your telescope and displays results for all current Tele Vue eyepieces.

Refer to the diagram and tables here for the definition of the input and out parameters.

apparent field: perceived span of sky seen through eyepiece (without telescope). Not used in true field (see) calculation.

exit pupil: image of objective formed by eyepiece. Location where full apparent field is seen.

f/#: a ratio that describes the relation between the aperture and focal length of the telescope -- important for photography

field stop: ring inside the eyepiece barrel that limits true and apparent field size

focal length: effective distance from entrance of an optical system to focal point

magnification: relative change in angular size of object

true field: span of sky seen through telescope/eyepiece combination

Glossary Formula table