Adjusts the focus.
In most cases, the inspection is performed while the subject is in focus, but in some cases it is better to blur the focus a little.
The aperture adjusts the brightness.
Depending on the inspection product, the brightness may be easier to inspect if it is bright, and conversely, it may be better to inspect if it is dark.
About aperture
We took a picture of the back of the cap of a PET bottle.
The two photos are taken with the same brightness, can you see the difference?
The photo on the left is in focus overall.
On the left, the lens is clised aperture to further increase the exposure time of the camera.
By closing the aperture and darkening the image, the exposure time is lengthened to restore the same brightness.
When you close the aperture, the “depth of focus (depth of field)” becomes deeper, making it easier to focus on both near and far objects.
About the number of pixels of the camera
The difference in the number of pixels of the camera is compared with the photo.
In the case of a 10.0 megapixel camera, silk-printed characters can be clearly seen, but at 0.3 Megapixel, small parts cannot be seen at all, and you can see only the presence or absence of large parts.
If the number of pixels is large, a finer inspection can be performed, and if the number of pixels is small, only a rough inspection is possible.
However, using a high pixel camera can significantly increase inspection time.
In order to detect what you want to detect in a shorter time, it is necessary to select “use a camera with as few pixels (coarse) as possible among the number of pixels that can be detected stably”.
