Compare eyepiece combinations without manually recomputing magnification, true field, and practical viewing limits every time.
Magnification
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Enter your telescope, eyepiece, and Barlow specs to estimate magnification, exit pupil, and field of view.
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200mm Dobsonian + 10mm eyepiece
Classic medium-high power setup
A common amateur astronomy combination where magnification, exit pupil, and true field all matter at once.
Result: 240x, 0.83 mm exit pupil, 0.34-degree true field
Wide-field sweep
Short eyepiece without a Barlow
Good for checking whether a low-power setup is wasting light or staying in a comfortable wide-field range.
Result: Lower magnification, larger exit pupil, and a much wider true field