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 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

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.

200°@6.3mm Fisheye M12 Lens

CIL219-F2.5-M12NIR

200° M12 Fisheye Lens
200° M12 Fisheye Lens
200° Mini Fisheye Lens
Mini M12 Fisheye Lens
$99.00

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

190°@4.2mm All-Sky M12 Lens

CIL015-F1.9-M12NIR

A miniature fisheye 1.5mm M12 lens for All-Sky cameras.
A miniature fisheye 1.5mm M12 lens for All-Sky cameras.
A 1.5mm S Mount RPi mini fisheye lens. The lens has an EFL of 1.5mm, F/# of 1.8, and a M12 Interface.
A fisheye 1.5mm M12 lens. The lens has an EFL of 1.5mm, F/# of 1.8, and a M12 S Mount Interface
$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.

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

230°@4.5mm Fisheye M12 Lens

CIL213-F2.3-M12A660

230 degree M12 Fisheye lens
230 degree M12 Fisheye lens
Ultra-wide fisheye lens with 230 degree field of view
230degree mini fisheye lens
$119.00

No Distortion 3.2mm Lens

CIL034-F2.7-M12A660

IP65 M12 Lens
IP65 M12 Lens
IP67 M12 Lens
IP67 FLIR S-Mount Lens M12 Lens
$39.00

Video Conferencing?

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

No Distortion 4.4mm M12 Lens

CIL043-F3.2-M12A650

A 12MP+ 4mm S-Mount Lens
A 12MP+ 4mm S-Mount Lens
A No Distortion 4.3mm S Mount Lens
A 14MP 4.3mm M12 Lens CIL043
$39.00

No Distortion 3.2mm Lens

CIL034-F2.7-M12A660

IP65 M12 Lens
IP65 M12 Lens
IP67 M12 Lens
IP67 FLIR S-Mount Lens M12 Lens
$39.00

Low Distortion 5.8mm M12 Lens

CIL058-F2.2-M12A650

6mm M12 Lens for IMX226
6mm M12 Lens for IMX226
6mm S Mount Lenses IMX226 IMX334
$79.00

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.

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

Low Distortion 6.8mm M12 Lens

CIL068-F2.5-M12A650

7mm M12 Lens
7mm M12 Lens
7mm M12 Lenses
7mm SMount Lens
$59.00

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