So I find myself confused – seems like more of a normal state anymore.
With regards to RI and tangent ratio. I would like to try my hand at an oval. I like he Gemcad PC02.051 – Oval for GGG 8×6. The diagram indicates the angles are for RI 1.540 (quartz) I would like to IRink with an RI of 2.xx. If I select topaz in Gem Cad an angle change is shown but it is well below the CA for topaz.
I’m old and slow and now more confused. Please help if you can.