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 5.8mm M12 Lens

CIL358-F1.9-M12A650

Wide-Angle 5.8mm M12 Lens

200°@6.3mm Fisheye M12 Lens

CIL219-F2.5-M12IR

200°@6.3mm Fisheye M12 Lens

Low Distortion 2.6mm M12 Lens

CIL028-F2.3-M12A650

Low Distortion 2.6mm M12 Lens

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

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

A 6mm M12 lens for 4K+ sensors
A 6mm M12 lens for 4K+ sensors
A 6mm cctv lens for raspberry pi HQ
A 6mm S-Mount lens for 1/1.8
CIL060-F2.8-M12A650
Low Distortion 6mm M12 Lens
$19.00
25mm M12 Lens
25mm M12 Lens
25mm S Mount Lens
25mm lens for FLIR Cameras
CIL260-F2.0-M12IR
Telephoto 26mm M12 Lens
$59.00
Short Compact 3.6mm M12 Lens CIL036
Short Compact 3.6mm M12 Lens CIL036
Compact 3.6mm M12 Lens CIL036
Compact 3.6mm S Mount Lens CIL036
CIL036-F2.2-M12A650
Small 3.3mm M12 Lens
$19.00
A 14MP 4mm M12 lens that is wide angle no distortion.
A 14MP 4mm M12 lens that is wide angle no distortion.
A 3.9mm M12 Lens pictured with the Raspberry Pi High Quality
A 4K M12 Lens for the Raspberry Pi High Quality Camera. CIL039.
CIL039-F2.8-M12A650
No Distortion 3.9mm 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-M12ANIR
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

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

Wide-Angle 4.8mm M12 Lens

CIL948-F2.0-M12B650

Wide-Angle 4.8mm M12 Lens

Wide-Angle 2.8mm M12 Lens

CIL329-F2.0-M12A650

Wide-Angle 2.8mm M12 Lens

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.

195°@4.7mm Fisheye M12 Lens

CIL216-F2.2-M12A650

195°@4.7mm Fisheye M12 Lens

Large Format 5.1mm M12 Lens

CIL050-F2.0-M12ANIR

Large Format 5.1mm M12 Lens

IR Corrected 4.4mm M12 Lens

CIL046-F2.0-M12A650

IR Corrected 4.4mm 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.

195°@4.7mm Fisheye M12 Lens

CIL216-F2.2-M12A650

195°@4.7mm Fisheye M12 Lens

Fisheye 2.5mm CS Mount Lens

CIL725-F1.6-CSANIR

Fisheye 2.5mm CS Mount Lens

Small 3.3mm M12 Lens

CIL036-F2.2-M12A650

Small 3.3mm M12 Lens

200°@5.7mm IP67 Fisheye M12 Lens

CIL217-F2.7-M12A650

200°@5.7mm IP67 Fisheye M12 Lens

190°@6.8mm Fisheye M12 Lens

CIL282-F1.8-M12B660

190°@6.8mm Fisheye M12 Lens

185°@7.8mm Fisheye M12 Lens

CIL227-F2.5-M12B660

185°@7.8mm 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.

190°@5.7mm Fisheye M12 Lens

CIL290-F2.2-M12A660

190°@5.7mm Fisheye M12 Lens

Small 2.5mm M12 Lens

CIL825-F2.4-M12ANIR

Small 2.5mm M12 Lens

Small 1.9mm M8/M12 Lens

CIL819-F2.0-M08A650

Small 1.9mm M8/M12 Lens