A CMOS Sensor Size Comparison and Format Type Look-Up Table

The Image Sensor Size and Pixel Size of a Camera is Critical to Image Quality

The sensor format size and pixel size of digital camera impacts nearly every performance attribute of a camera.

There are general rules of thumb for how the these will impact the image quality of a camera. Each of these will change the form and function of camera. The tradeoffs tend to be uniformly continuous over multiple degrees of freedom.

Each camera application has different requirements, so the selection of a CMOS image sensor needs to be made on a case-by-case basis. We've done our best to categorize the trends of sensor-type adoption by industry.

A CMOS Image Sensor Size Comparison to Explain Digital Camera Sensor Size Tradeoffs

Digital Camera Sensor Format Types are confusing because of Cathode Ray Tubes

The format type of a digital camera sensor is one of the most confusing and ridiculous concepts in the vision industry. This is a result of approximations made in the early-to-mid 1900s when electrical-based sensors were first invented.

For example:

  • A 1″ Type image sensor with 4:3 aspect ratio is 12.8mm Horizonal * 9.6mm Vertical * 16mm Diagonal
  • A 1/3″ Type image sensor with 4:3 aspect ratio is 4.8mm Horizontal * 3.6mm Vertical * 6mm Diagonal

Well that doesn’t seem to make any sense, does it? 1" is 25.4mm and 1/3 of 1" is 8.5mm! Even 1/3 of the 1" Format Diagonal should be 5mm! 

Digital Camera Sensor Size Comparison Formula

Let's take the 1" format type as an example. Part of the cathode ray tube's diameter was the tube wall, and was not used for imaging purposes, reducing from 25.4mm to 16mm.

So, a lens suitable for a 1" Type cathode ray tube did not need an image circle that extended to the entire 25.4mm tube diameter.

Unfortunately, the formula for the digital image sensor type has a discontinuity occurring between the 1/2" and 1/2.3" format size.

We surmise (perhaps incorrectly) this may have been a result of the manufacturing process for early television cathode ray tubes. Other experts in our network have noticed that the equation is approximately divided by the square root of 2, however, it is still unclear to us what the original motivation was.

What this means when someone references a CMOS Image Sensor Format Type

This subjective classification means that manufacturers can apply 'best judgement' when publishing a Format Type for their sensor.

The means that engineers should use the exact output pixel count and pixel pitch (size) when considering a lens, such as a CS Mount Lens or M12 Lens.

The majority of sensors on the market approximately adhere to the Format Type dimensions below, which are calculated from the formula above:

The Take-Away: There is no substitute for exact values when selecting a lens

Most manufacturers are consistent and accurate with their Format Type classifications. However, we've run across numerous specification sheets which are mis-classified.

To repeat, always use the exact output pixel count and pixel pitch (size) when finding a lens!

If you've figured out which sensor you're using and want to calculate the 35mm Format Type Equivalent EFL, check out our Camera Field of View Calculator.

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

Wide-Angle 3.6mm M12 Lens

CIL336-F1.9-M12A650

Wide-Angle 3.6mm M12 Lens

188°@6.6mm IP67 M12 Fisheye

CIL222-F2.0-M12A650

188°@6.6mm IP67 M12 Fisheye

185°@7.8mm Fisheye M12 Lens

CIL227-F2.5-M12ANIR

185°@7.8mm Fisheye M12 Lens

Does it Require an IP65+ Lens?

We offer IP65+ variants of many lenses. These are suitable for applications  exposed to the environment, without a window.

Mobile Robotics?

Find a low F# or low distortion lens to optimize your computer vision framerate.

Low Distortion 2.2mm M12 Lens

CIL023-F2.2-M12A650

Low Distortion 2.2mm M12 Lens

Wide-Angle 3.5mm M12 Lens

CIL335-F1.8-M12A660

Wide-Angle 3.5mm M12 Lens

Mid-Range 7.6mm M12 Lens

CIL080-F1.8-M12IR

Mid-Range 7.6mm M12 Lens

200°@5.7mm IP67 Fisheye M12 Lens

CIL217-F2.7-M12ANIR

200°@5.7mm IP67 Fisheye M12 Lens

Telephoto 35mm M12 Lens

CIL350-F2.4-M12A650

Telephoto 35mm M12 Lens

Telephoto 26mm M12 Lens

CIL260-F2.0-M12NIR

Telephoto 26mm M12 Lens

Surveillance?

Our low F#, high resolution lenses are suitable for 180° dome cameras, low light, and active IR illuminated scenes.

Consumer / AR+VR?

Our high resolution fisheye lenses will let you design 360° cameras and and stereographic lenses are equivalent to "GoPro" lenses.

226°@3.9mm Fisheye M12 Lens

CIL212-F2.2-M12A660

226°@3.9mm Fisheye M12 Lens

Low Distortion 2.6mm M12 Lens

CIL028-F2.3-M12A650

Low Distortion 2.6mm M12 Lens

GoPro 3.0mm M12 Lens

CIL331-F2.5-M12A660

GoPro 3.0mm M12 Lens

Low Distortion 1.8mm M12 Lens

CIL018-F2.8-M12A650

Low Distortion 1.8mm M12 Lens

Low Distortion 2.6mm M12 Lens

CIL028-F2.3-M12A650

Low Distortion 2.6mm M12 Lens

No Distortion 3.9mm M12 Lens

CIL039-F2.8-M12IR

No Distortion 3.9mm M12 Lens

Video Conferencing?

Our wide-angle, low distortion, high resolution M12 lenses result in optimal object deformation without post-processing.

Aerial Robotics?

Our light-weight, miniature lenses are ideal for collision avoidance, long-distance viewing, and end-customer viewing.

Small 2.1mm M12 Lens

CIL821-F2.4-M12B650

Small 2.1mm M12 Lens

Large Format 3.5mm M12 Lens

CIL334-F2.2-M12A660

Large Format 3.5mm M12 Lens

Wide-Angle 3.5mm M12 Lens

CIL335-F1.8-M12A660

Wide-Angle 3.5mm M12 Lens

Surveillance?

Our low F#, high resolution lenses are suitable for 180° dome cameras, low light, and active IR illuminated scenes.

Video Conferencing?

Our wide-angle, low distortion, high resolution M12 lenses result in optimal object deformation without post-processing.