zhaoyy89 |
2012-03-20 15:55 |
dpgf怎么算呢
玻璃參數(shù)設(shè)置里面有三個(gè)值,前兩個(gè)是Index、Abbe數(shù)Vd,還有一個(gè)是dpgf。Vd = (Nd-1)/(Nf-Nc),其中Nd是587nm折射率,Nf是486.1327nm折射率,Nc是656.2725nm折射率。但是dpgf怎么算呢?論壇里有的人說是G光和F光的相對(duì)色散,Dpgf = (Ng-Nf)/(Nf-Nc),那Ng對(duì)應(yīng)哪個(gè)波長(zhǎng)的光呢?
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