July 2,2009 05:32
[Note] achromatic, apochromat
After:
Before:
"A concave lens of flint glass is commonly combined with a convex lens of crown glass to produce an achromatic doublet"
by John Dollond
Crown glass: low refractive index (≒1.52), low dispersion (with Abbe numbers around 60)
Flint glass: high refractive index (1.45-2.00), low dispersion (with Abbe numbers around 50-55)
More details:CLN, No.12/2000
Before:
"A concave lens of flint glass is commonly combined with a convex lens of crown glass to produce an achromatic doublet"
by John Dollond
Crown glass: low refractive index (≒1.52), low dispersion (with Abbe numbers around 60)
Flint glass: high refractive index (1.45-2.00), low dispersion (with Abbe numbers around 50-55)
More details:CLN, No.12/2000
引用URL
http://cgi.blog.roodo.com/trackback/9357551
