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

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

Wide-Angle 4mm M12 Lens

CIL339-F1.6-M12B640

Wide-Angle 4mm M12 Lens

No Distortion 4.2mm M12 Lens

CIL042-F1.9-M12A650

No Distortion 4.2mm M12 Lens

190°@6.8mm Fisheye M12 Lens

CIL282-F1.8-M12B660

190°@6.8mm Fisheye M12 Lens

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

Stereographic Tailored Distortion Fisheye M12 Lens
Stereographic Tailored Distortion Fisheye M12 Lens
M12 Lens Fisheye Stereographic
Stereographic M12 Lens
CIL273-F2.0-M12A650
200°@5.8mm Fisheye Lens
$39.00
High resolution M12 Fisheye lens
High resolution M12 Fisheye lens
S-Mount Fisheye Lenses
Embedded Camera Fisheye Lenses
CIL281-F1.8-M12A650
190°@6.4mm Fisheye Lens
$59.00

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.

Low Distortion 6.8mm M12 Lens

CIL068-F2.5-M12A650

Low Distortion 6.8mm M12 Lens

200°@7.2mm Fisheye M12 Lens

CIL324-F1.9-M12B650

200°@7.2mm Fisheye M12 Lens

190°@5.4mm Stereographic Fisheye M12 Lens

CIL293-F2.2-M12ANIR

190°@5.4mm Stereographic Fisheye 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.

IP67 12mm M12 Lens

CIL120-F2.4-M12ANIR

IP67 12mm M12 Lens

186°@5.2mm IR Corrected Fisheye M12 Lens

CIL239-F2.0-M12A650

186°@5.2mm IR Corrected Fisheye M12 Lens