When considering a manual or motorized video system to inspect for defects of anomalies, one must evaluate the optimum magnification, lighting, ergonomics, and flexibility. Manual and motorized systems supply a wide variety of magnifications all in one system.
Be sure to evaluate the area of the part for the largest feature one would need to see on the monitor screen at one time (Lowest Magnification).
What is the smallest feature required to be viewed at one time (highest magnification). Resolution is also known as the inspection systems ability to accurately reproduce the level of detail of each part.
The working distance is the required fixed distance from the part to the lens which will allow the operator to view the part in focus.
The depth of field is the difference between the closest and the farthest distance that a part may be moved under the lens without going out of focus. Most inspections systems have a macro lens (low magnification) with a very high depth of field (more room for hands).
Macro Lenses generally have a wide field of view which allows the operator to see more of the part at one time.