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

190°@9.1mm Fisheye M12 Lens

CIL231-F1.9-M12A650

190°@9.1mm Fisheye M12 Lens

Wide-Angle 3.5mm M12 Lens

CIL335-F1.8-M12A660

Wide-Angle 3.5mm M12 Lens

Low Distortion 6mm M12 Lens

CIL060-F2.8-M12A650

Low Distortion 6mm M12 Lens

Telephoto 26mm M12 Lens

CIL260-F2.0-M12IR

Telephoto 26mm M12 Lens

Small 3.3mm M12 Lens

CIL036-F2.2-M12A650

Small 3.3mm M12 Lens

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

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
A 12MP+ 4mm S-Mount Lens
A 12MP+ 4mm S-Mount Lens
A No Distortion 4.3mm S Mount Lens
A 14MP 4.3mm M12 Lens CIL043
CIL043-F3.2-M12B650
No Distortion 4.4mm M12 Lens
$39.00
Large Format 5.1mm M12 Lens
Large Format 5.1mm M12 Lens
5mm M12 Lens Allied Vision
5mm S Mount Lens for Computer Vision
CIL050-F2.0-M12A650
Large Format 5.1mm M12 Lens
$59.00
8mm 1/1.7
8mm 1/1.7
8mm S-Mount Lens for 4K+ sensors
8mm M12 Lens for 12MP+ 1/1.7
CIL080-F1.8-M12IR
Mid-Range 7.6mm M12 Lens
$59.00
6mm M12 Lens for Blackfly S-mount cameras
6mm M12 Lens for Blackfly S-mount cameras
6mm M12 Lens for FLIR Blackfly S and AR0234
6mm Lens for IMX290
CIL061-F1.9-M12B650
Fast 6mm M12 Lens
$39.00
3mm Wide Angle M12 Lens IMX415
3mm Wide Angle M12 Lens IMX415
Sony IMX415 Lens
M12 S Mount Lens for IMX415
CIL327-F1.5-M12A660
Wide-Angle 2.7mm M12 Lens
$39.00

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

200°@4.5mm MiniFisheye M12 Lens

CIL914-F2.4-M12B650

200°@4.5mm MiniFisheye 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.

IR Corrected 4.4mm M12 Lens

CIL046-F2.0-M12A650

IR Corrected 4.4mm M12 Lens

Small 1.9mm M8/M12 Lens

CIL819-F2.0-M08A650

Small 1.9mm M8/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.

Large Format 3.5mm M12 Lens

CIL334-F2.2-M12C660

Large Format 3.5mm M12 Lens

185°@7.8mm Fisheye M12 Lens

CIL227-F2.5-M12B660

185°@7.8mm Fisheye M12 Lens

Small 2.1mm M12 Lens

CIL821-F2.4-M12ANIR

Small 2.1mm M12 Lens

185°@7.8mm Fisheye M12 Lens

CIL227-F2.5-M12B660

185°@7.8mm Fisheye M12 Lens

190°@9.1mm Fisheye M12 Lens

CIL231-F1.9-M12A650

190°@9.1mm Fisheye M12 Lens

Wide Angle 3.2mm M12 Lens

CIL332-F1.8-M12A660

Wide Angle 3.2mm 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.

Small 1.9mm M8/M12 Lens

CIL819-F2.0-M08A650

Small 1.9mm M8/M12 Lens

Telephoto 50mm M12 Lens

CIL051-F2.8-M12A650

Telephoto 50mm M12 Lens

Large Format 5.5mm M12 Lens

CIL056-F2.4-M12A650

Large Format 5.5mm M12 Lens