Partial dispersion parameter

[dibyendumajumdar]

Re the difficulty I had with the ray tracing of glasses with partial dispersion, the patent literature often has a partial dispersion parameter in addition to the abbe number and refractive index. Can this be used by ray-optics? Example of a patent with two elements that have partial dispersion:

[mjhoptics]

This could potentially be helpful. The example above specifies the partial between F (486nm) and g (436nm), as well as Nd and Vd. If the partial were from d (587nm) to F, we'd have enough data to get 3 wavelength/index pairs (d, C, F), but with the F/g partial I can only get the index differences between C, F and g. This might be enough to do a 3 term Hartmann fit, but I haven't tried that.

So conceptually, yes, we could create a new glass class that took nd, Vd and PFd (or possibility PgF) as input, fit a Hartmann polynomial to it and hopefully see a better model for ED glasses.

[dibyendumajumdar]

I guess probably not worth it ... As if we have exact glass types that is better anyway.