Camera Sensor Size Guide
CMOS Sensor Size Chart and engineering reference for understanding image sensor format types. This guide explains the vidicon tube heritage behind sensor format nomenclature and provides reference data for proper lens selection.
How Does CMOS Sensor Size Impact Camera Performance?
The sensor format size of a digital camera determines its fundamental performance characteristics. Low-light sensitivity, dynamic range, physical dimensions, cost, and lens requirements are related to sensor format size. Each application and camera project demands weighing tradeoffs.
If the pixel architecture is the same, larger pixels collect more light thus improving low light performance. However, a larger sensor needs a lens with a larger image circle, and holding image quality and corner illumination across that wider field is the harder design problem. M12 lenses serve sensors up to approximately 1/1.6" format, while C-mount lenses cover larger sensor formats.
Why Are Digital Camera Sensor Format Types So Confusing?
The format type classification system originates from video camera tubes manufactured before CCD and CMOS sensors. These vidicon tubes had opaque regions outside the active cathode area due to mechanical structures holding the tube and electrodes.
The imaging area was significantly smaller than the tube's outer diameter. When solid-state CCD sensors replaced tubes, manufacturers maintained the existing format naming convention to preserve compatibility with established lens systems. The result: modern sensor format designations describe the equivalent vidicon tube diameter that would produce the same image circle, not the sensor's actual dimensions.
Key Insight
The "inch" in sensor format types is not a measurement unit. A "1/2.8 inch" sensor does not measure 1/2.8 inches in any dimension. The format designation indicates compatibility with a historical vidicon tube standard.
What Is the Mathematical Relationship Between Format Type and Actual Sensor Size?
We've done our best to fit a "modern-day" curve to the format names, using commonly agreed upon datapoints of 1" = 16.0mm, 1/2" = 8.0mm, 1/3" = 6.0mm, 1/4" = 4.5mm, then cross-referencing as many other articles as possible. Treat that fit as a convenience, not a definition: the format names are a historical list inherited from tube diameters, not a continuous function of sensor diagonal.
That is why the curve breaks between the 1/2" and 1/2.3" format sizes, and why the chart below still carries the legacy "image dissector" label for the tube diameter. When the number matters, take width and height from the sensor datasheet or from the reference table below.
Engineering Note
Never calculate field of view using format type alone. Manufacturers may deviate from convention, and aspect ratios vary. Use actual pixel count and pixel pitch from the datasheet for accurate optical calculations.
Sensor Format Reference Table
The following table lists common CMOS sensor formats with their approximate dimensions. Most sensors conform approximately to these values.
Download the Sensor Format Reference Chart
Printable PDF lookup table with all sensor format types, dimensions, and aspect ratios.
Download PDF Chart →| Format Type | Diagonal (mm) | Width × Height (4:3) | Typical Applications |
|---|---|---|---|
| 1/4" | 4.5 | 3.6 × 2.7 | Low-cost surveillance, webcams |
| 1/3" | 6.0 | 4.8 × 3.6 | Security cameras, drones |
| 1/2.8" | 6.4 | 5.1 × 3.8 | IP cameras, machine vision |
| 1/2.7" | 6.7 | 5.4 × 4.0 | Automotive ADAS, robotics |
| 1/2.3" | 7.7 | 6.2 × 4.6 | Action cameras, drones |
| 1/2" | 8.0 | 6.4 × 4.8 | Compact cameras, drones |
| 1/1.8" | 8.9 | 7.1 × 5.3 | Surveillance, robotics |
| 1/1.7" | 9.4 | 7.5 × 5.6 | Embedded vision, Video-conferencing |
| 2/3" | 11.0 | 8.8 × 6.6 | Global shutter machine vision |
| 1" | 16.0 | 12.8 × 9.6 | Global shutter machine vision |
| 1.2" | 20.0 | 16.0 × 12.0 | High-end mirrorless |
| 4/3" | 21.6 | 17.3 × 13.0 | Micro Four Thirds cameras |
| APS-C | 28.2 | 23.6 × 15.6 | DSLR, cinema cameras |
| Full Frame | 43.3 | 36.0 × 24.0 | Cinema, professional video |
35mm Equivalent Focal Length Calculator
Convert between actual focal length and 35mm equivalent for different sensor formats.
35mm Equivalent Result
Sensor Format Classification Calculator
Enter your sensor's actual dimensions to determine its format classification.
Sensor Classification
–
–
How Do I Match a Lens to My Sensor Format?
The lens image circle must equal or exceed the sensor diagonal. A full-frame fisheye lens is no exception: it is specified to cover the diagonal, and accepting barrel distortion does not substitute for coverage. A circular fisheye is the deliberate exception, since its image circle is designed to fall inside the sensor's short side.
A lens rated for 1/2" format covers sensors up to 8mm diagonal. Using a lens on a larger sensor causes vignetting (dark corners). Using a lens on a smaller sensor wastes optical performance but does not cause image degradation.
For embedded vision applications with sensors up to 1/1.8" format (8.9mm diagonal), M12 mount lenses provide compact, cost-effective solutions. For larger sensor formats, C-mount lenses extend coverage beyond what most M12 optics reach, and many C-mount models add an adjustable iris and focus ring for depth-of-field control.
Lens Selection Rule
Always select a lens rated for your sensor format or larger, unless you deliberately chose a circular fisheye or intend to crop after capture. A lens rated for 2/3" format works on 1/2", 1/3", and 1/4" sensors. The reverse is not true: a 1/3" lens on a 1/2" sensor will vignette.
What Sensor Format Should I Choose for My Application?
Sensor format selection depends on resolution requirements, light sensitivity needs, physical space constraints, and budget. Consider these guidelines:
- Mobile Robotics (1/4" to 1/1.7"): Compact sensors pair well with lightweight M12 lenses for robotics. Prioritize wide field of view for navigation.
- Automotive Vision (1/2.8" to 1/1.7"): Balance between compact packaging and low-light performance. Automotive M12 lenses offer ruggedized designs.
- Machine Vision (1/1.7" to 1"): Larger formats enable higher resolution and global shutter. Global shutter sensors in 2/3" and 1" formats pair with C-mount lenses for precision applications.
- Surveillance (1/3" to 1/2"): Cost-effective formats with proven lens availability. Surveillance lenses optimize for day/night operation.
How Does Exposure Interact With F-Number, Gain, and Motion Blur?
Sensor format sets the physical area available to collect light, but how much light actually reaches each pixel in a given frame comes down to exposure: the combination of f-number, exposure (integration) time, and sensor gain. Image-plane irradiance scales with 1/(f/#)², so each full stop increase in f-number (for example F/2.8 to F/4) roughly halves the light reaching the sensor. See the f-number guide for the full derivation.
Lengthening exposure time is one way to recover light lost to a smaller aperture, but it also lengthens the smear from any object or camera motion during the frame. At typical conveyor speeds of 200–500mm/s, an extra 1ms of exposure time adds roughly 0.2–0.5mm of motion blur at the object. Our motion blur guide and camera exposure guide cover how this tradeoff affects detection accuracy in vision systems.
Raising sensor gain is the third lever. Gain amplifies the analog signal, and its accompanying noise, at each pixel without collecting more photons, so it recovers brightness but reduces usable dynamic range and raises image noise. Because full-well capacity scales with pixel area, though full-well density is sensor-specific, sensors with larger pixels, which for a given resolution come from larger formats, hold more signal headroom before gain-driven noise becomes limiting. This is one more reason format selection is a system-level tradeoff, not just a field-of-view decision.
Practical Order of Operations
For a fixed working distance and lighting budget: open the aperture (lower f-number) as far as depth of field allows, keep exposure time short enough to hold motion blur within your application's tolerance, and treat gain as the last adjustment, since it only amplifies whatever signal the optics and sensor already captured.
Frequently Asked Questions
Why doesn't a 1/2.8 inch sensor measure 1/2.8 inches?
The inch designation originates from 1950s vidicon television camera tubes. The format name referred to the outer glass tube diameter, not the active imaging area. The active cathode area was only about two-thirds of the tube diameter due to mechanical mounting structures.
When solid-state sensors replaced tubes, manufacturers retained the naming convention for backward compatibility with existing lens systems. A "1/2.8 inch" sensor has approximately 6.4mm diagonal, nowhere close to 0.357 inches (9.07mm).
How do I calculate field of view from sensor format?
Do not use format type directly for field of view calculations. The format designation is an approximation that varies between manufacturers. Instead, use the actual sensor dimensions from the datasheet.
Angle of view in degrees follows from the sensor dimension alone: AoV = 2 × arctan(sensor_dimension / (2 × focal_length)), for a rectilinear lens. Linear field of view in millimeters also needs a working distance: FOV = 2 × WD × tan(AoV / 2). Use our Field of View Calculator with actual sensor width or height in millimeters for accurate results.
What happens if I use a lens rated for a smaller sensor format?
The lens image circle will not cover the entire sensor, causing vignetting (dark corners). The severity depends on the format mismatch. A 1/3" lens on a 1/2" sensor may show significant corner darkening. A 1/2" lens on a 2/3" sensor will have severe vignetting.
Always select a lens rated for your sensor format or larger. You can use a 2/3" lens on a 1/3" sensor without issues: you simply use the central portion of the lens's image circle.
How do I calculate the required focal length for my application?
The governing relationship: Focal Length = (Working Distance × Sensor Width) / Scene Width.
Example: imaging a 2-meter wide scene from 3 meters with a 1/2.8" sensor (5.1mm width) requires 3000mm × 5.1mm / 2000mm = 7.65mm, so a 7.5mm or 8mm lens. Use our EFL Calculator for precise calculations.
How does f-number affect exposure and motion blur?
F-number controls how much light reaches the sensor per unit time: image-plane irradiance scales with 1/(f/#)², so a wider aperture (lower f-number) reaches the same exposure level in less time.
Shorter exposure time reduces motion blur, which scales roughly with object speed multiplied by exposure time. A narrower aperture forces a choice between a longer exposure (more blur), brighter illumination, or higher sensor gain (more noise, less dynamic range).
Can Commonlands assemble complete camera modules?
Yes. Commonlands provides camera module assembly services including optical design, sensor integration (Sony, OmniVision, OnSemi), lens holder selection, and complete module assembly with focusing and thread locking.
We support volumes from 100 to 100,000+ units annually. Contact our engineering team with your specifications.