Criteria for optics
The choice of the right lens depends directly on the sensor of the camera used. The parameters chip size and pixel size are important with regard to the selection.
• Sensor size - image circle diameter
the lens must illuminate the entire sensor surface to avoid vignetting (shading) in the image.
• Pixel size - optical resolution
The better the optical resolution of the lens, the finer the structures can be transmitted.
• Lens resolution - Image scale
To be able to better resolve details of an object and to have a clear edge recognition, these details should be mapped to approx. 4 pixels.
The lens must be designed at least for the sensor size (always specified in inches), such as the size of the camera sensor used. However, a camera with a smaller sensor can also be used.
In addition, there are still terms that play an important role in connection with lenses.
The focal length of an optical system is the distance between the optical reference plane (main plane) and the point at which the light rays (infinity) are bundled in a single point (focal point). Behind this point is the image plane on which the camera sensor is located.
The ratio of image to object size describes the magnification of the optics and is directly related to the focal length of the lens and the working distance.
Depth of field is a measure of an area in which the image of the object is considered to be sharp. This is influenced by many factors, but mainly by the aperture selected. The smaller the aperture, the greater the depth of field.