One formula · your inputs
Astronomy camera field of view calculator
Sensor dimensions and focal length define the ideal rectilinear angular field.
The page computes all three axes separately and does not apply crop-factor shortcuts or lens-distortion corrections.
Formula
How it is calculated
field = 2 × atan(sensor dimension ÷ (2 × focal length))- Enter active sensor dimensions.
- Use the effective focal length of the optical train.
- Calculate width, height and diagonal as separate angles.
What the result represents
The rectilinear pinhole-camera field-angle relation.
The page keeps every decision-bearing quantity visible as an input. It does not look up a product catalogue, current market value or hidden recommended preset.
Limits of the model
The result is an idealised optical or geometric estimate from user-entered values. It does not model seeing, optical quality, central obstruction, transmission, distortion, focus error, tracking or sensor calibration.
Use the number to compare transparent scenarios. Verify critical observations, equipment combinations and coordinates independently.
Questions about this calculation
Does this camera-field calculator choose equipment for me?
No. It evaluates only the displayed formula with the numbers you enter and does not make a purchase, compatibility or safety decision.
Why can the observed result differ?
Real optics and observing conditions add obstructions, transmission losses, aberrations, seeing, focus and measurement uncertainty that are outside the arithmetic model.
Can I use the result for navigation or safety-critical work?
No. SkyClock tools are transparent planning estimates, not certified navigation, engineering or safety instruments.
Need a dated lunar calendar? Browse official USNO moon phases for 2026–2050.