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

Wide-Angle 4mm M12 Lens

CIL341-F2.0-M12A650

Wide-Angle 4mm M12 Lens

Telephoto 50mm M12 Lens

CIL051-F2.8-M12ANIR

Telephoto 50mm M12 Lens

215°@6.8mm M12 Fisheye Lens

CIL220-F2.3-M12B650

215°@6.8mm M12 Fisheye Lens

Low Distortion 6.8mm M12 Lens

CIL068-F2.5-M12A650

Low Distortion 6.8mm M12 Lens

Small 2.1mm M12 Lens

CIL821-F2.4-M12ANIR

Small 2.1mm M12 Lens

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

Telephoto 50mm M12 Lens
Telephoto 50mm M12 Lens
50mm Board Lens
50mm S Mount Lens
CIL051-F2.8-M12ANIR
Telephoto 50mm M12 Lens
$70.00
215 degree Miniature Fisheye Lens CIL220
215 degree Miniature Fisheye Lens CIL220
M12 Mini Fisheye Lens
Miniature Fisheye Lens
CIL220-F2.3-M12B650
215°@6.8mm M12 Fisheye Lens
$39.00
7mm M12 Lens GMSL Camera
7mm M12 Lens GMSL Camera
7mm M12 Lenses USB3 FLIR
Basler Dart Camera 7mm SMount Lens
CIL068-F2.5-M12A650
Low Distortion 6.8mm M12 Lens
$49.00
A 2.1mm M12 Lens for 1/3
A 2.1mm M12 Lens for 1/3
Tiny Pinhole Lens for S-Mount Cameras
15mm TTL Short M12 Lens for Surveillance
CIL821-F2.4-M12ANIR
Small 2.1mm M12 Lens
$39.00
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
Wide Angle Low Distortion 2mm S-Mount Lens CIL023
Wide Angle Low Distortion 2mm S-Mount Lens CIL023
Wide Angle Low Distortion 2mm S-Mount Lens CIL023
Wide Angle Low Distortion 2mm S-Mount Lens CIL023
CIL023-F2.2-M12A650
Low Distortion 2.2mm M12 Lens
$39.00

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

Low Distortion 6mm M12 Lens

CIL059-F1.7-M12B650

Low Distortion 6mm M12 Lens

Low Distortion 6.8mm M12 Lens

CIL068-F2.5-M12A650

Low Distortion 6.8mm 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.

12mm C-Mount Lens 1.1" 12MP

CIL512-F2.8-CMANIR

12mm C-Mount Lens 1.1" 12MP

16mm C-Mount Lens 1.1" 12MP

CIL513-F2.8-CMANIR

16mm C-Mount Lens 1.1" 12MP

Small 1.9mm M8/M12 Lens

CIL819-F2.0-M08A650

Small 1.9mm M8/M12 Lens

Small 2.5mm M12 Lens

CIL825-F2.4-M12ANIR

Small 2.5mm 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.

Telephoto 35mm M12 Lens

CIL350-F2.4-M12A650

Telephoto 35mm M12 Lens

200°@6.3mm Fisheye M12 Lens

CIL219-F2.5-M12NIR

200°@6.3mm Fisheye M12 Lens

190°@5.7mm Fisheye M12 Lens

CIL290-F2.2-M12A660

190°@5.7mm Fisheye M12 Lens

188°@6.6mm IP67 M12 Fisheye

CIL222-F2.0-M12A650

188°@6.6mm IP67 M12 Fisheye

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 2.8mm Lens

CIL829-F2.5-M08A650

Small 2.8mm Lens

Large Format 3.5mm M12 Lens

CIL334-F2.2-M12C660

Large Format 3.5mm M12 Lens