| 摘要 |
The invention provides an objective lens with a front lens group and a rear lens group spaced apart from the front group. The front group comprises at least two doublet components one of which is a crown positive element cemented to a flint negative element which has a higher refractive index and dispersion values than those of the crown glass. The other doublet component of the front group is a crown positive element and a flint negative element in which the flint and crown glasses have similar refractive indices but dissimilar dispersions with the flint glass having a positive red relative partial dispersion deviant.
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