Don't you have to balance the lens resolution with the sensor resolution to optimize the overall optical resolution?
Yes, you are correct. I was referring to this briefly in my discussion on lenses where I broadly mentioned using a "high-quality" lens.
The details of optical resolution were beyond this "fundamentals" discussion. However, in the vast majority of industrial machine vision applications, optical resolution does not come into question. In my experience, only a small number of industrial applications approach Nyquist limits in feature detection, and the diffraction limits of any good quality lens system should be sufficient overall.
To your point though, it certainly is important in certain applications to evaluate optical resolution to ensure feature detail.
This was adapted from the Vision Systems Design webcast “Introduction to machine vision: Definitions, components, benefits, applications,” presented by David Dechow, Principal Vision Systems Architect, Integro Technologies. View archived and upcoming webcasts here.