Examples
Examples
Try the starting example
- Eyepiece field stop diameter (mm)
- 27
- Telescope focal length (mm)
- 1000
- Approximate true field (degrees)
- 1.546892
- Approximate true field (arcminutes)
- 92.813525
Try another scenario
- Eyepiece field stop diameter (mm)
- 29.700000000000003
- Telescope focal length (mm)
- 1000
- Approximate true field (degrees)
- 1.70156
- Approximate true field (arcminutes)
- 102.093575
Calculation method
Calculation method
Approximate true field (degrees)
True field angle=2atan(field-stop diameter/(2 telescope focal length)).
Approximate true field (arcminutes)
True field angle=2atan(field-stop diameter/(2 telescope focal length)).
Symbols and units
- a
- Eyepiece field stop diameter (mm)
- b
- Telescope focal length (mm)
Use the units shown. A list keeps the order in which you enter its values. The symbol ^ means “raised to the power of”.
Assumptions & limits
Assumptions & limits
- Field-stop tangent-plane geometry, no apparent-field/magnification approximation. Supported limits: All required fields must be finite values of the exact declared type and within displayed bounds. Lists contain1–1000 finite numbers. JSON tables are numeric rectangular rows, at most100 rows and30 columns; individual tools have stricter shape/domain constraints. Field-stop tangent-plane geometry, no apparent-field/magnification approximation.
Are these inputs private?
These calculations run in your browser. A shared link contains the values you choose to share. Only questions submitted to the separate AI finder are sent to OpenAI.
Further reading
Background reading; this does not imply endorsement or independent review of SumFizz.