A worked example
A 23.5 × 15.6 mm sensor at 500 mm focal length spans approximately 2.692° × 1.787°.
Camera field
Calculate rectangular camera field of view and compare it with an entered angular target size.
YOUR LITTLE WORKBENCH
Camera field
Start with an example and change it to your setup. Results update as you type.
Calculation method+
Field on each axis = 2 atan(sensor size ÷ (2 × effective focal length)), converted to degrees.
YOUR LIVE RESULT ✦
Horizontal field of view
2.6924 °- Vertical field of view
- 1.7875 °
- Diagonal field of view
- 3.2314 °
- Horizontal field
- 161.5444 arcmin
- Vertical field
- 107.249 arcmin
- Target fits the rectangle
- ✓
Target size is user-entered in arcminutes; the circle represents an angular size, not a current celestial image. Distortion and obstructions are excluded.
THE METHOD / 01
Know what goesinto your result.
Field on each axis = 2 atan(sensor size ÷ (2 × effective focal length)), converted to degrees.
Keep the assumptions clear
Target size is user-entered in arcminutes; the circle represents an angular size, not a current celestial image. Distortion and obstructions are excluded.
A FEW USEFUL ANSWERS
Good to know.
Are my inputs uploaded?
No. Calculations run locally in your browser. The host still receives normal requests for website pages and assets.
Can I keep my result?
Use the download controls for the current tool or print from your browser. Typing scores and camping plans can also be saved locally; see the privacy page for details.
Do I need an account?
No sign-up, paid API or subscription is required. Both language versions use the same calculation logic.
SKYKIND / TOOLKIT
A little help for every step.
01
Magnification
Calculate magnification, exit pupil and effective focal ratio from your optical setup.
Open tool02
Eyepiece fields
Compare two eyepieces on the same telescope with an approximate true-field diagram.
Open tool04
Pixel scale
Convert pixel size and focal length to arcseconds per pixel, with binning and a user-entered seeing value.
Open tool