Glossary · Machine vision
Exposure time
Also known as: Shutter time, Integration time
German: Belichtungszeit
In imaging, exposure time is the period during which the image sensor collects light for one image. Longer exposure gives brighter images but causes motion blur when the object moves; shorter exposure needs more light or gain.
- Machine vision
In one sentence
Exposure time is how long the sensor collects light for one image; longer exposures brighten images but blur moving parts.
Example
At a conveyor speed of 1 m/s, an exposure time of 50 microseconds keeps motion blur to 0.05 mm, so the camera works with strobed light.
How it applies
- Engineering: Maximum exposure time for moving parts follows from speed and acceptable blur. Short exposures combined with Strobe lighting freeze motion without raising gain and noise.
- Commissioning: Exposure, gain and lighting are set together; auto-exposure is usually avoided in inspection because it changes image brightness unpredictably.
- Documentation: The documentation team should record exposure and gain settings with the reasons (speed, lighting) so that later changes to line speed trigger a check of the vision settings.
Exposure time vs. frame rate
Exposure time is how long one image collects light; Frame rate is how many images per second the camera can deliver. Exposure time limits the maximum frame rate but they are set separately.