This Camera Focal Length Calculator finds the Lens Focal Length From a Field of View

Camera Lens Focal Length Calculator

A Camera Focal Length Calculator. This Calculates a Lens EFL for Cameras.
A Camera Focal Length Calculator. This Calculates a Lens EFL for Cameras.

This effective focal length calculator helps you select a lens to use with your camera. The calculator takes your target field of view (angle of view) and camera specification then provides the required lens EFL.

The calculator uses the camera lens focal length equation. This formula is different than the lens maker's equation which is intended for simple thin lens elements.

The Optical Effective Focal Length (EFL) should not be confused with the Mechanical Back-Focal Length (BFL). The EFL determines the field of view of the camera while the BFL determines whether a lens will focus on a camera.

Read Our Camera Calculator & Optics Design Page, or Click below Use our Other Camera Calculators

Camera Field of View Calculator. FoV Calculator
Camera Depth of Field Calculator. DoF Calculator.
Camera Angle of View Calculator for Camera Lens Selection. AoV Calculator.

Building a Camera? Use Our Wide-Angle Lens Calculator or Browse Below

Aerial Robotics?

Our light-weight, miniature lenses are ideal for collision avoidance, long-distance viewing, and end-customer viewing.

Telephoto 50mm M12 Lens

CIL051-F2.8-M12A650

Telephoto 50mm M12 Lens
Telephoto 50mm M12 Lens
50mm Board Lens
50mm S Mount Lens
$79.00

Large Format 5.5mm M12 Lens

CIL056-F2.4-M12A650

6mm M12 Lens CIL056
6mm M12 Lens CIL056
6mm S Mount Lens
Econsystems See3Cam_CU8a
$39.00

Telephoto 16.0mm M12 Lens

CIL160-F1.9-M12A650

16mm M12 Lens CIL160
16mm M12 Lens CIL160
16mm M12 lenses CIL160
16mm S Mount Lens
$39.00

Surveillance?

Our low F#, high resolution lenses are suitable for 180° dome cameras, low light, and active IR illuminated scenes.

Small 3.3mm M12 Lens

CIL036-F2.2-M12A650

Short Compact 3.6mm M12 Lens CIL036
Short Compact 3.6mm M12 Lens CIL036
Compact 3.6mm M12 Lens CIL036
Compact 3.6mm S Mount Lens CIL036
$29.00

Large Format 3.5mm M12 Lens

CIL334-F2.2-M12A660

3.5mm M12 Lens for IMX226 AR0821 IMX537
3.5mm M12 Lens for IMX226 AR0821 IMX537
S-Mount Drone Lens for Wide Angle IMX226
Wide Angle Drone Lens for IMX226
$39.00

185°@7.8mm Fisheye M12 Lens

CIL227-F2.5-M12ANIR

Wide Angle Fisheye Lens for S Mount
Wide Angle Fisheye Lens for S Mount
Fisheye Wide Angle M12 Lens
Board Mount Lens Wide Angle Fisheye
$49.00

Surveillance?

Our low F#, high resolution lenses are suitable for 180° dome cameras, low light, and active IR illuminated scenes.

Consumer / AR+VR?

Our high resolution fisheye lenses will let you design 360° cameras and and stereographic lenses are equivalent to "GoPro" lenses.

Video Conferencing?

Our wide-angle, low distortion, high resolution M12 lenses result in optimal object deformation without post-processing.

Video Conferencing?

Our wide-angle, low distortion, high resolution M12 lenses result in optimal object deformation without post-processing.

Mobile Robotics?

Find a low F# or low distortion lens to optimize your computer vision framerate.