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

Low Distortion 6.8mm M12 Lens

CIL068-F2.5-M12A650

Low Distortion 6.8mm M12 Lens

Wide-Angle 6.8mm M12 Lens

CIL368-F1.8-M12A650

Wide-Angle 6.8mm M12 Lens

Low Distortion 8mm M12 Lens

CIL083-F2.8-M12A650

Low Distortion 8mm M12 Lens

Small 2.1mm M12 Lens

CIL821-F2.4-M12ANIR

Small 2.1mm M12 Lens

F-theta Wide-Angle 4mm M12 Lens

CIL340-F2.0-M12A650

F-theta Wide-Angle 4mm M12 Lens

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

Raspberry Pi HQ Camera 8mm M12 Lens
Raspberry Pi HQ Camera 8mm M12 Lens
8mm M12 Lenses IMX464
8mm M12 Lens Raspberry Pi High Quality
CIL083-F2.8-M12A650
Low Distortion 8mm M12 Lens
$29.00
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
A 4mm M12 Lens which is 14MP and F-theta | CIL340
A 4mm M12 Lens which is 14MP and F-theta | CIL340
A wide-angle 4mm S-Mount Lens
4mm Wide-Angle M12 Lens CIL340
CIL340-F2.0-M12A650
F-theta Wide-Angle 4mm M12 Lens
$79.00
190°@5.7mm Fisheye M12 Lens
190°@5.7mm Fisheye M12 Lens
190°@5.7mm Fisheye M12 Lens
190°@5.7mm Fisheye M12 Lens
CIL290-F2.2-M12A660
190°@5.7mm Fisheye M12 Lens
$29.00
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

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

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

No Distortion 4.4mm M12 Lens

CIL043-F3.2-M12B650

No Distortion 4.4mm M12 Lens

No Distortion 6mm M12 Lens

CIL062-F2.8-M12A650

No Distortion 6mm 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.

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

No Distortion 3.2mm Lens

CIL034-F2.3-M12A660

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.

Wide-Angle 3.5mm M12 Lens

CIL335-F1.8-M12A660

Wide-Angle 3.5mm M12 Lens

Small 3.3mm M12 Lens CIL036

CIL036-F2.2-M12A650

Small 3.3mm M12 Lens CIL036