Views: 0 Author: Site Editor Publish Time: 2026-05-03 Origin: Site
Introduction
If you have ever used an endoscope in a dark pipe or body cavity, you know that brightness matters. One key specification that determines how much light reaches the sensor is the F‑number (also called f‑stop or Lens aperture). Simply put, a smaller F‑number means a larger opening and a brighter image. This article explains what F‑number means for endoscope camera module designs, how it affects image quality, and why it is critical for medical and industrial inspection.
What Is F‑Number?
The F‑number (Optical aperture) is the ratio of the lens’s focal length to the diameter of the entrance pupil. It is written as f/N, e.g., f/2.0, f/2.8.
Smaller F‑number (e.g., f/1.8) = larger aperture = more light = brighter image.
Larger F‑number (e.g., f/8.0) = smaller aperture = less light = darker image.
In endoscopy, the primary concern is light gathering because the environment is dark and the sensor is small.
Why F‑Number Matters
An endoscope camera module works in tight, dark spaces – a pipe, engine cylinder, or body cavity. Illumination is limited (small LEDs or fibre optics). A low F‑number (e.g., f/1.8) collects more light, allowing the cmos module camera to produce a bright, low‑noise image without excessive LED heat.
For a micro endoscope camera module (diameter under 2 mm), the aperture is physically very small. Achieving a low F‑number is hard; many have F‑3.0 or higher, making them less sensitive.
F‑Number and Resolution
A 1080p endoscope camera module (or hd camera module) needs enough light to resolve fine details. A high F‑number (e.g., f/4.0) dims the image, forcing gain (amplification) that adds noise and reduces effective resolution. High‑quality USB Camera Module and UVC camera module products for professional use often have F‑numbers of f/1.8 to f/2.4.
Typical F‑Numbers by Endoscope Type
Type | Typical F‑Number | Why |
|---|---|---|
Medical laparoscope (10 mm) | f/1.8 – f/2.2 | Large lens, bright for surgery |
Industrial borescope (5–8 mm) | f/2.0 – f/2.8 | Balance light and depth of field |
Consumer USB endoscope (5.5 mm) | f/2.8 – f/3.5 | Cost‑optimised |
Micro endoscope (≤2 mm) | f/3.5 – f/5.6 | Physical size limits aperture |
1080p endoscope camera module | f/2.0 – f/2.8 | Good low‑light performance |
Trade‑Off: Light vs. Depth of Field
A larger aperture (small F‑number) gives more light but reduces depth of field – only a narrow range of distances is sharp. For endoscopy, we often want everything from 5 mm to 50 mm in focus. To increase depth of field, you would use a smaller aperture (higher F‑number), but that darkens the image. Designers compromise (e.g., f/2.4) and rely on wide‑angle lenses for natural depth of field.
F‑Number in Different Module Types
USB Camera Module (UVC) – Plug‑and‑play endoscopes often have fixed apertures around f/2.8. A UVC camera module with f/2.0 performs better in dark cavities.
Medical endoscope camera module – Surgical scopes aim for f/1.8 to f/2.2, balancing brightness and depth of field.
Micro endoscope camera module – Under 2 mm diameter, lenses are tiny. Most are f/3.5+ and rely on sensitive cmos module camera sensors and bright LEDs.
Choosing the Right F‑Number
Application | Recommended F‑Number | Note |
|---|---|---|
Medical surgery | f/1.8 – f/2.2 | Maximum brightness |
Industrial inspection | f/2.0 – f/2.8 | Good balance |
Home DIY / automotive | f/2.8 – f/3.5 | Affordable, adequate |
Very narrow cavities (<3 mm) | f/3.5 – f/5.6 | Accept lower light, use more LED |
High‑end 1080p endoscope camera module | f/2.0 – f/2.4 | Sharp, bright, low noise |
F‑Number and USB Endoscope Performance
A USB Camera Module that connects to a laptop draws power from the host. If the F‑number is too high, the image will be dark, forcing longer exposure (motion blur) or gain (noise). A good UVC camera module for professional inspection should specify its Optical aperture – look for f/2.4 or lower.
Sincere’s Endoscope Camera Modules
At Sincere, we design endoscope camera module products with carefully chosen F‑numbers:
Endoscope camera module – Custom aperture from f/1.8 to f/5.6.
USB Camera Module – UVC compliant, low f# for bright images.
Lens aperture – Optimised for light gathering or depth of field.
Hd camera module – 1080p modules with f/2.0 – f/2.8.
UVC camera module – Plug‑and‑play with specified F‑number.
Micro endoscope camera module – Ultra‑compact (down to 1.5 mm) with best possible aperture.
1080p endoscope camera module – Balanced optics for crisp, bright images.
Summary
The F‑number (Optical aperture) is a critical specification for any endoscope camera module. A low F‑number (e.g., f/1.8) gives brighter images but shallower depth of field. A high F‑number (e.g., f/3.5) gives more depth of field but needs more light. For most medical and industrial inspection, an F‑number of f/2.0 to f/2.8 works well for hd camera module applications. When choosing a USB Camera Module or UVC camera module, check the F‑number. A micro endoscope camera module may have a higher F‑number due to size limits – compensate with brighter LEDs. For a 1080p endoscope camera module, F‑numbers below f/2.4 ensure excellent low‑light performance.
Contact Sincere to discuss your endoscope camera module and aperture requirements.
