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

Small 1.9mm M8/M12 Lens

CIL819-F2.0-M08A650

Small 1.9mm M8/M12 Lens

Large Format 5.5mm M12 Lens

CIL056-F2.4-M12A650

Large Format 5.5mm M12 Lens

IP67 12mm M12 Lens

CIL120-F2.4-M12A650

IP67 12mm M12 Lens

195°@5.2mm Fisheye Lens

CIL818-F2.0-M12A660

195°@5.2mm Fisheye Lens

Wide-Angle 4.8mm M12 Lens

CIL948-F2.0-M12B650

Wide-Angle 4.8mm M12 Lens

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

4mm M12 Lens for See3Cam_CU81
4mm M12 Lens for See3Cam_CU81
4.4mm S Mount Lens CIL343
4.4mm S-Mount Lens
CIL343-F2.3-M12ANIR
Wide-Angle 4.4mm M12 Lens
$49.00
IMX462 M12 Lens CIL079
IMX462 M12 Lens CIL079
8mm M12 Lens CIL079
8mm S Mount Lenses CIL079
CIL079-F2.0-M12A650
Ingress Protected 7.9mm M12 Lens
$39.00
IR Corrected Day Night Fisheye Lens S-Mount
IR Corrected Day Night Fisheye Lens S-Mount
Surveillance Fisheye Lens S-Mount
Security Camera Fisheye Lens Day and Night
CIL239-F2.0-M12A650
186°@5.2mm IR Corrected Fisheye M12 Lens
$59.00
18mm M12 Lenses
18mm M12 Lenses
18mm M12 Lens
Telephoto S Mount M12 Lens 18mm
CIL178-F2.0-M12A650
Telephoto 18mm M12 Lens
$39.00
10MP IP69 Wide Angle M12 Lens CIL333
10MP IP69 Wide Angle M12 Lens CIL333
IMX678 M12 Lens Wide Angle
Small S-Mount Lens1/1.8
CIL333-F2.0-M12ANIR
Wide-Angle 3.5mm M12 Lens
$39.00
Wide-Angle 4mm M12 Lens
Wide-Angle 4mm M12 Lens
Wide-Angle 4mm M12 Lens
CIL339-F1.6-M12A640
Wide-Angle 4mm M12 Lens
$99.00

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.

Telephoto 16mm M12 Lens

CIL160-F1.9-M12A650

Telephoto 16mm M12 Lens

IP67 12mm M12 Lens

CIL120-F2.4-M12A650

IP67 12mm M12 Lens

195°@5.2mm Fisheye Lens

CIL818-F2.0-M12A660

195°@5.2mm Fisheye 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.