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

200°@2.9mm Fisheye M12 Lens

CIL208-F2.2-M12A650

200°@2.9mm Fisheye M12 Lens

220°@4.0mm Stereographic M12 Fisheye

CIL207-F1.9-M12A650

220°@4.0mm Stereographic M12 Fisheye

Ingress Protected 7.8mm M12 Lens

CIL079-F2.0-M12A650

Ingress Protected 7.8mm M12 Lens

186°@5.2mm IR Corrected Fisheye M12 Lens

CIL239-F2.0-M12A650

186°@5.2mm IR Corrected Fisheye M12 Lens

Telephoto 18mm M12 Lens

CIL178-F2.0-M12A650

Telephoto 18mm M12 Lens

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

IR Corrected 12mm M12 Lens
IR Corrected 12mm M12 Lens
12mm S-Mount Lens
IR Corrected M12 Lens
CIL122-F2.0-M12A650
IR Corrected 12mm M12 Lens
$59.00
8mm Edmund Blue Series M12 Lens 58203 83-940
8mm Edmund Blue Series M12 Lens 58203 83-940
8mm S-Mount Lens
8mm M12 Lens allied Vision Basler
CIL382-F2.0-M12A650
Wide-Angle 7.8mm M12 Lens
$29.00
Molded Glass Aspheres M12 Lens Low Distortion
Molded Glass Aspheres M12 Lens Low Distortion
Molded Glass S-Mount
M12 Lenses Low Distoriton
CIL093-F2.4-M12A650
All Glass Low Distortion 2.8mm M12 Lens
$119.00

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

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.

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.

Wide-Angle 3.6mm Lens

CIL336-F1.9-M12A650

Wide-Angle 3.6mm Lens

200°@5.5mm Fisheye M12 Lens

CIL237-F2.2-M12A660

200°@5.5mm Fisheye M12 Lens

Wide-Angle 4mm M12 Lens

CIL341-F2.0-M12A650

Wide-Angle 4mm 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.