Nomograph Editorial

I was fortunate enough to be in the first undergraduate class for Optical Engineering at the University of Arizona's Optical Sciences center.

I hated the nomograph when I first saw it.

I learned the Cartesian lens makers equation as a sophomore from Dr. Dereniak. I learned the empirical lens makers equation from my Dad via Jenkins and white. I forget what we usedfor 3rd semester freshman physics. As a senior Dr. Greivenkamp covered the Cartesian method again. I messed the sign convention up enough that I was really annoyed with this basic, all important equation. Not to mention Newton's equation.

My last semester as a senior I took optical instrumentation from Dr. Macleod. He introduced us to this nomograph and I can distinctly remember getting very agitated by it. Here was yet another way to understand imaging. I resented having to learn another method. Consequently I had a mental block against using the nomograph and doing similar triangles - I usually went back to the Cartesian form of the lens makers equation to check myself.

Then a funny thing happened.

I started working as a real lens designer. To keep up with all the geniuses around me I had to adapt at quickly comprehending image - object relationships. This is where I reverted to this nomograph to rapidly do optical engineering.

As a professional mentor I've been pushing this because it is not taught in schools and yet I think it provides an incredible, easy to comprehend insight into a lens.

I am very appreciative to Angus MacCleod for teaching me this method. If you are a thin film designer, Angus's software uses Admittance diagrams to describe coatings. Another very potent graphical technique.

I have to thank Peter Wheel for showing me how interconnected graphs can be used to do complex system engineering for Infrared systems!

Also thanks to Patrick McCarthy for sharing an ancient nomograph book!