Calculate your optical setup parameters instantly.
Telescope & Eyepiece Data
Optical Results
Magnification
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Focal Ratio
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Exit Pupil
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True FOV
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Interpreting Results
Exit Pupil
A value between 2mm and 3mm is often considered ideal for general observing, while larger exit pupils (>5mm) are better for low-light, wide-field views.
True Field of View (TFOV)
This tells you the actual slice of the sky you see through the eyepiece. A higher TFOV is better for finding objects and viewing large, diffuse targets like nebulae.