Field of view (FOV) is the angular diameter of the sky area that you're observing through your telescope or binoculars. It's measured in degrees, minutes, and seconds of arc. FOV is an essential parameter in astronomy, as it determines the size of the area you can observe in the sky.
This isn’t a web tool—it’s a planetarium program. You set your equipment once, then press “Oculars” to see a realistic simulation of the sky through any eyepiece. You can “zoom” in and out virtually.
TFOV (degrees) = AFOV / Magnification
Field of view | Basic Information about Binoculars | Nikon Consumer
Q: Do I need to pay for an astro FOV calculator? A: Some astro FOV calculators, such as Stellarium and SkySafari, offer free versions or trials, while others, such as Celestron SkyPortal, require a purchase. astro fov calculator top
A comprehensive, pre-loaded dropdown database containing hundreds of commercial telescopes, lenses, focal reducers, and imaging sensors.
If you choose to calculate your angular field of view manually, use the following standard formula: Field of view (FOV) is the angular diameter
Input your telescope's focal length. Factor in any focal reducers (e.g., ) or Barlow lenses.
The angular dimensions of the sky captured, measured in degrees, arcminutes, or arcseconds. This isn’t a web tool—it’s a planetarium program