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

Camera Lens Effective 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.

Here are a Few M12 Lenses. Search all 50+ Using Our M12 Lens Calculator

215°@6.8mm M12 Fisheye Lens

CIL220-F2.3-M12B650

215°@6.8mm M12 Fisheye Lens

Small 2.1mm M12 Lens

CIL821-F2.4-M12ANIR

Small 2.1mm M12 Lens

Low Distortion 2.2mm M12 Lens

CIL023-F2.2-M12A650

Low Distortion 2.2mm M12 Lens

GoPro 3.0mm M12 Lens

CIL331-F2.5-M12B650

GoPro 3.0mm M12 Lens

Low Distortion 1.8mm M12 Lens

CIL018-F2.8-M12A650

Low Distortion 1.8mm M12 Lens

We Also have Cost Effective 12MP+ C-Mount Lenses for Machine Vision and Factory Automation.

50mm C-Mount Lens 1.1" 12MP

CIL516-F2.8-CMANIR

50mm C-Mount Lens 1.1" 12MP

35mm C-Mount Lens 1.1" 20MP+

CIL545-F2.8-CMANIR

35mm C-Mount Lens 1.1" 20MP+
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
CIL821-F2.4-M12ANIR
Small 2.1mm M12 Lens
$39.00
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
CIL023-F2.2-M12A650
Low Distortion 2.2mm M12 Lens
$39.00
3.1mm Wide Angle M12 Lens
3.1mm Wide Angle M12 Lens
3mm S-Mount Lens
3mm M12 Lens
CIL331-F2.5-M12B650
GoPro 3.0mm M12 Lens
$39.00
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
CIL018-F2.8-M12A650
Low Distortion 1.8mm M12 Lens
$39.00
5mm M12 Lens for IMX334
5mm M12 Lens for IMX334
5mm M12 Lens IMX334
5mm S Mount Lens IMX334
CIL046-F2.0-M12A650
IR Corrected 4.4mm M12 Lens
$79.00
6mm M12 Lenses S Mount Lens
6mm M12 Lenses S Mount Lens
6mm S Mount Lenses GMSL Camera Lens
6mm M12 Lens AR0821 AR0820 IMX678
CIL059-F1.7-M12B650
Low Distortion 6mm M12 Lens
$49.00

What's Your Application? Our Lenses Cover the Spectrum.

Low Distortion 6.8mm M12 Lens

CIL068-F2.5-M12A650

Low Distortion 6.8mm M12 Lens

200°@5.7mm IP67 Fisheye M12 Lens

CIL217-F2.7-M12A650

200°@5.7mm IP67 Fisheye M12 Lens

Fast 6mm M12 Lens

CIL061-F1.9-M12B650

Fast 6mm M12 Lens

Mobile Robotics?

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

Factory Machine Vision?

Our cost-effective compact C-Mount lenses are designed for up to 1.1"~1.2" format global shutter sensors.

25mm C-Mount Lens 1.1" 12MP

CIL514-F2.8-CMANIR

25mm C-Mount Lens 1.1" 12MP

35mm C-Mount Lens 1.1" 12MP

CIL515-F2.8-CMANIR

35mm C-Mount Lens 1.1" 12MP

50mm C-Mount Lens 1.1" 12MP

CIL516-F2.8-CMANIR

50mm C-Mount Lens 1.1" 12MP

Low Distortion 2.7mm M12 Lens

CIL027-F2.8-M12A650

Low Distortion 2.7mm M12 Lens

Small 2.5mm M12 Lens

CIL825-F2.4-M12ANIR

Small 2.5mm M12 Lens

No Distortion 4.4mm M12 Lens

CIL043-F3.2-M12B650

No Distortion 4.4mm M12 Lens

Intelligent Everywhere?

Our low distortion lenses with multiple F# can be used to optimize your depth of field.

Surveillance?

Our fisheye and IR Corrected lenses are suitable for doorbell cameras and active IR illuminated scenes.

200°@6.3mm Fisheye M12 Lens

CIL219-F2.5-M12IR

200°@6.3mm Fisheye M12 Lens

186°@5.2mm IR Corrected Fisheye M12 Lens

CIL239-F2.0-M12A650

186°@5.2mm IR Corrected Fisheye M12 Lens

Low Distortion 6mm M12 Lens

CIL059-F1.7-M12B650

Low Distortion 6mm M12 Lens

188°@6.6mm IP67 M12 Fisheye

CIL222-F2.0-M12A650

188°@6.6mm IP67 M12 Fisheye

No Distortion 3.2mm Lens

CIL034-F2.3-M12B650

No Distortion 3.2mm Lens

Fast 6mm M12 Lens

CIL061-F1.9-M12B650

Fast 6mm M12 Lens

Does it Require Getting Dirty?

Our IP67 and IP69K lenses are suitable for applications exposed to the environment.

Aerial Robotics?

Our tiny lenses are ideal for collision avoidance and object recognition.

Large Format 3.5mm M12 Lens

CIL334-F2.2-M12C660

Large Format 3.5mm M12 Lens

Telephoto 16mm M12 Lens

CIL160-F1.9-M12A650

Telephoto 16mm M12 Lens

Wide-Angle 3.5mm M12 Lens

CIL335-F1.8-M12A660

Wide-Angle 3.5mm M12 Lens