Eyepiece Calculator

Use consistent measurement units. Millimeters recommended.

Telescope: Aperture: Focal Length:
Eyepiece: Focal Length: Apparent FOV: Barlow:

Focal Ratio is: f/5

Magnification is: 50x

True Field of View is: 1.0 degrees

Exit Pupil is: 2.0 mm

Fully dilated pupil size
Lowest Useful Magnification is:

Best use:


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