Thursday, July 7, 2011

Wise words on lighting

The machine vision and inspection supplement published in Test & Measurement magazine is usually quite informative, but the June 2011 issue has a Q&A that I just have to share with you.

The “victim” of the interrogation is Dan Holste, Director of Engineering at Banner, and the title of the piece is “When vision is the best choice.” Dan starts by discussing how a vision system is just another sensing technology, but one with the ability to characterize an area rather than being a single point sensor like a photoelectric sensor. Where it gets really interesting though is when Dan is asked “How does vision sensing give more information?”

His answer is that lighting is 90% of the equation. Dan goes on to say that the goal should be to create contrast between what you want to see and what you don’t care about.H

I think most of us know that, but how much effort do we put in to lighting studies? If I’m honest, I know I could do more to investigate different options. I could probably make more use of polarization, to give one example, and I should perhaps spend more time exploring the impact of wavelength on my images. But there’s never as much time as we’d like and I admit that sometimes I take the view that its good enough and I’ll do the rest in software. But how long does that take?

Dan offers some wise words. Read them and heed them.

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