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.

188°@6.6mm IP67 M12 Fisheye

CIL222-F2.0-M12A650

Mini Fisheye S Mount Lens
Mini Fisheye S Mount Lens
Mini Fisheye M12 Lens
Miniature Fisheye M12 Lens
$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

Fast 6mm M12 Lens

CIL061-F1.9-M12B650

6mm M12 Lens for S-mount cameras
6mm M12 Lens for S-mount cameras
6mm M12 Lens for FLIR and AR0234
6mm Lens for IMX290
$39.00

Surveillance?

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

Low Distortion 6mm M12 Lens

CIL060-F2.8-M12A650

A 6mm M12 lens for 4K+ sensors
A 6mm M12 lens for 4K+ sensors
A 6mm cctv lens for raspberry pi HQ
A 6mm S-Mount lens for 1/1.8
$29.00

Telephoto 12mm M12 Lens

CIL125-F2.4-M12IR

Telephoto 12mm M12 Lens
Telephoto 12mm M12 Lens
Telephoto M12 Lens 12mm
Telephoto 12mm M12 Lens
Telephoto 12mm S-Mount Lens
$39.00

Low Distortion 2.2mm M12 Lens

CIL023-F2.2-M12A650

Wide Angle Low Distortion 2mm S-Mount Lens CIL023
Wide Angle Low Distortion 2mm S-Mount Lens CIL023
Wide Angle Low Distortion 2mm S-Mount Lens CIL023
Wide Angle Low Distortion 2mm S-Mount Lens CIL023
Wide Angle Low Distortion 2mm S-Mount Lens CIL023
$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.

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

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

195°@5.2mm Fisheye Lens

CIL818-F2.0-M12A660

Miniature M8 Fisheye Lens
Miniature M8 Fisheye Lens
M8 Miniature Fisheye Lens CIL818
M8 Mini Fisheye Lens
$39.00

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.

200°@5.7mm IP67 Fisheye M12 Lens

CIL217-F2.7-M12ANIR

Mini Fisheye S Mount Lens
Mini Fisheye S Mount Lens
Tiny Fisheye Lens
Miniature Fisheye
$39.00

Wide-Angle 4.4mm M12 Lens

CIL344-F1.9-M12B660

Wide Angle M12 Lens
Wide Angle M12 Lens
Wide Angle S-Mount Lens
AR0820 M12 Lens
$49.00

188°@6.6mm IP67 M12 Fisheye

CIL222-F2.0-M12A650

Mini Fisheye S Mount Lens
Mini Fisheye S Mount Lens
Mini Fisheye M12 Lens
Miniature Fisheye M12 Lens
$39.00