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.

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

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

Wide-Angle 3.5mm M12 Lens

CIL335-F1.8-M12A660

3.5mm Wide-Angle M12 Lens
3.5mm Wide-Angle M12 Lens
3.5mm Wide-Angle S-Mount Lens
Wide-Angle M12 Lens CIL335
$49.00

Surveillance?

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

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

Telephoto 35mm M12 Lens

CIL350-F2.4-M12A650

35mm M12 Lens
35mm M12 Lens
35mm Board Mount Lens
35mm S Mount Lens
$59.00

Telephoto 26mm M12 Lens

CIL260-F2.0-M12NIR

25mm M12 Lens
25mm M12 Lens
25mm S Mount Lens
25mm lens for FLIR Cameras
$79.00

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.

226°@3.9mm Fisheye M12 Lens

CIL212-F2.2-M12A660

Mini M12 Fisheye Lens for Board Mount Cameras
Mini M12 Fisheye Lens for Board Mount Cameras
Mini M12 Fisheye Lens for Board Mount Cameras
Mini M12 Fisheye Lens for Board Mount Cameras
Mini M12 Fisheye Lens for Board Mount Cameras
$59.00

Low Distortion 2.6mm M12 Lens

CIL028-F2.3-M12A650

A 2.8mm M12 lens with a wide angle and no distortion for the RPi HQ Camera.
A 2.8mm M12 lens with a wide angle and no distortion for the RPi HQ Camera.
A 2.8mm M12 lens with a wide angle and no distortion for the RPi HQ Camera.
A 2.8mm M12 lens with a wide angle and no distortion for the RPi HQ Camera.
$39.00

GoPro 3.0mm M12 Lens

CIL331-F2.5-M12A660

3.1mm Wide Angle M12 Lens
3.1mm Wide Angle M12 Lens
3mm S-Mount Lens
3mm M12 Lens
$39.00

Video Conferencing?

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

Low Distortion 1.8mm M12 Lens

CIL018-F2.8-M12A650

135° 4K+ low distortion M12 lens for IMX335 and AR0521
135° 4K+ low distortion M12 lens for IMX335 and AR0521
135° low distortion S-Mount Lens
No Distortion Wide Angle M12 Lens
$39.00

Low Distortion 2.6mm M12 Lens

CIL028-F2.3-M12A650

A 2.8mm M12 lens with a wide angle and no distortion for the RPi HQ Camera.
A 2.8mm M12 lens with a wide angle and no distortion for the RPi HQ Camera.
A 2.8mm M12 lens with a wide angle and no distortion for the RPi HQ Camera.
A 2.8mm M12 lens with a wide angle and no distortion for the RPi HQ Camera.
$39.00

No Distortion 3.9mm M12 Lens

CIL039-F2.8-M12IR

A 14MP 4mm M12 lens that is wide angle no distortion.
A 14MP 4mm M12 lens that is wide angle no distortion.
A 3.9mm M12 Lens pictured with the Raspberry Pi High Quality
A 4K M12 Lens for the Raspberry Pi High Quality Camera. CIL039.
14MP 4mm M12 lens on IMX178
$39.00

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.

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

Wide-Angle 3.5mm M12 Lens

CIL335-F1.8-M12A660

3.5mm Wide-Angle M12 Lens
3.5mm Wide-Angle M12 Lens
3.5mm Wide-Angle S-Mount Lens
Wide-Angle M12 Lens CIL335
$49.00

Mid-Range 7.6mm M12 Lens

CIL080-F1.8-M12IR

8mm 1/1.7
8mm 1/1.7
8mm S-Mount Lens for 4K+ sensors
8mm M12 Lens for 12MP+ 1/1.7
$59.00