Specialty calculators

Astronomy and astrophotography

What an eyepiece shows, what a sensor samples, and how long the sky will let you expose for.

Magnification and true field of view

Magnification, true field, exit pupil and useful power range.

Focal ratio and resolving power

Focal ratio, resolving limits, limiting magnitude and light grasp.

Pixel scale and sensor matching

Arcseconds per pixel, field of view and sampling against the seeing.

Maximum exposure before trailing

Longest untracked exposure by NPF, 500 and 400, with sky drift.

Dew heater wattage

Heater power, current and battery drain for a dew strap.

Integration time

Total integration, elapsed time, SNR gain and nights to a target.

These are planning figures, not a substitute for a standard, a specification or a professional. Check anything that matters against the source your trade actually works to.