500 Rule Star Trail Exposure Calculator
500 Rule Star Trail Exposure: a planned Super Calculator tool. Covers focal length. Stub page: the tool, its formula and a worked example are not published yet.
500 Rule Star Trail Exposure Calculator is a planned calculator in the science section of Super Calculator, covering telescopes.
What this calculator will compute
Inputs: focal length, crop factor, declination and pixel pitch.
Formula, recorded as scope and not yet verified against a primary source: Maximum seconds = 500 divided by (focal length times crop factor), or NPF rule refinement.
Written for nightscape photographers avoiding trailed stars.
Status
This page is a stub. The calculator is not built, no figure on this page has been verified against the authority that sets it, and nothing here should be used to make a decision. The page exists so that the site structure is complete and so that articles can link this concept on first mention.
The stub carries noindex, nofollow and is excluded from the sitemap.