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

185°@7.8mm Fisheye M12 Lens

CIL227-F2.5-M12B660

185°@7.8mm Fisheye M12 Lens

200°@5.7mm IP67 Fisheye M12 Lens

CIL217-F2.7-M12A650

200°@5.7mm IP67 Fisheye M12 Lens

226°@3.9mm Fisheye M12 Lens

CIL212-F2.2-M12A660

226°@3.9mm Fisheye M12 Lens

230°@4.5mm Fisheye M12 Lens

CIL213-F2.3-M12A660

230°@4.5mm Fisheye M12 Lens

188°@6.6mm IP67 M12 Fisheye

CIL222-F2.0-M12A650

188°@6.6mm IP67 M12 Fisheye

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

Mini Fisheye S Mount Lens
Mini Fisheye S Mount Lens
Mini Fisheye M12 Lens
Miniature Fisheye M12 Lens
CIL222-F2.0-M12A650
188°@6.6mm IP67 M12 Fisheye
$39.00
AR0822 M12 Lens CIL358
AR0822 M12 Lens CIL358
6mm Wide Angle Lens CIL358
OX08B40 Lens
CIL358-F1.9-M12A650
Wide-Angle 5.8mm M12 Lens
$49.00
200° M12 Fisheye Lens
200° M12 Fisheye Lens
200° Mini Fisheye Lens
Mini M12 Fisheye Lens
CIL219-F2.5-M12IR
200°@6.3mm Fisheye M12 Lens
$79.00
A 2.8mm M12 lens with a wide angle and no distortion for the RPi HQ Camera.
A 2.8mm M12 lens with a wide angle and no distortion for the RPi HQ Camera.
A 2.8mm M12 lens with a wide angle and no distortion for the RPi HQ Camera.
A 2.8mm M12 lens with a wide angle and no distortion for the RPi HQ Camera.
CIL028-F2.3-M12A650
Low Distortion 2.6mm M12 Lens
$39.00
3mm Mini Fisheye M12 Lens
3mm Mini Fisheye M12 Lens
3mm S Mount Fisheye Lens Raspberry Pi
Miniature Fisheye Lens
CIL231-F1.9-M12A650
190°@9.1mm Fisheye M12 Lens
$99.00
3.5mm Wide-Angle M12 Lens
3.5mm Wide-Angle M12 Lens
3.5mm Wide-Angle S-Mount Lens
Wide-Angle M12 Lens CIL335
CIL335-F1.8-M12A660
Wide-Angle 3.5mm M12 Lens
$49.00

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

Low Distortion 7.2mm M12 Lens

CIL872-F2.8-M12A650

Low Distortion 7.2mm M12 Lens

Wide-Angle 3.5mm M12 Lens

CIL335-F1.8-M12A660

Wide-Angle 3.5mm M12 Lens

Low Distortion 7.8mm M12 Lens

CIL078-F2.0-M12A650

Low Distortion 7.8mm 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.

GoPro 3.0mm M12 Lens

CIL331-F2.5-M12B650

GoPro 3.0mm M12 Lens

Mid-Range 7.6mm M12 Lens

CIL080-F1.8-M12IR

Mid-Range 7.6mm M12 Lens

Low Distortion 4.5mm Lens

CIL045-F3.5-M12A650

Low Distortion 4.5mm 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.

Wide-Angle 3.2mm CS Mount Lens

CIL032-F2.0-CSA650

Wide-Angle 3.2mm CS Mount Lens

Large Format 5.1mm M12 Lens

CIL050-F2.0-M12ANIR

Large Format 5.1mm M12 Lens

190°@9.1mm Fisheye M12 Lens

CIL231-F1.9-M12A650

190°@9.1mm Fisheye M12 Lens

Wide-Angle 2.8mm M12 Lens

CIL329-F2.0-M12A650

Wide-Angle 2.8mm M12 Lens

Wide-Angle 3.6mm Lens

CIL336-F1.9-M12A650

Wide-Angle 3.6mm Lens

200°@6.3mm Fisheye M12 Lens

CIL219-F2.5-M12IR

200°@6.3mm 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.

Low Distortion 2.7mm M12 Lens

CIL027-F2.8-M12A650

Low Distortion 2.7mm M12 Lens

200°@6.3mm Fisheye M12 Lens

CIL219-F2.5-M12IR

200°@6.3mm Fisheye M12 Lens

Low Distortion 7.2mm M12 Lens

CIL872-F2.8-M12A650

Low Distortion 7.2mm M12 Lens