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.

Low Distortion 3.0mm M12 Lens

CIL030-F2.1-M12A650

3mm m12 lens
3mm m12 lens
$59.00

IP67 12mm M12 Lens

CIL120-F2.4-M12A650

IP67 12mm M12 Lens
IP67 12mm M12 Lens
IP67 12mm M12 Lens
IP67 12mm M12 Lens
$39.00

Surveillance?

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

Small 2.1mm M12 Lens

CIL821-F2.4-M12B650

A 2.1mm M12 Lens for 1/3
A 2.1mm M12 Lens for 1/3
Tiny Pinhole Lens for S-Mount Cameras
15mm TTL Short M12 Lens for Surveillance
$39.00

215°@6.8mm M12 Fisheye Lens

CIL220-F2.3-M12B650

215 degree Miniature Fisheye Lens CIL220
215 degree Miniature Fisheye Lens CIL220
M12 Mini Fisheye Lens
Miniature Fisheye Lens
$39.00

Wide-Angle 2.7mm M12 Lens

CIL327-F1.5-M12A660

3mm Wide Angle M12 Lens IMX415
3mm Wide Angle M12 Lens IMX415
Sony IMX415 Lens
M12 S Mount Lens for IMX415
$39.00

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.