True field of view
Also called: TFOV, true field, field of view, FOV.
How much sky you see through the eyepiece — roughly its apparent field divided by the magnification.
A 52° eyepiece at 50× shows about 1° of sky: two full Moons across. At 200× the same eyepiece shows a quarter of a degree. Big targets — the Pleiades, the Andromeda Galaxy, the Veil — need a wide true field; tiny ones don't.
In AstroPilot
Object pages draw your eyepiece's field with the object to scale, using a real photograph.