| 摘要 |
A lens system comprises a first lens positive in power, a second lens positive in power, a third lens negative in power, a fourth lens positive in power, and a fifth lens negative in power. The lens system meets a criteria of 1.6<TT/f<1.8, 1.6<F/F<SUB>2</SUB><1.8, and -0.6<F/F<SUB>5</SUB><-0.4, wherein TT denotes a distance between an object-side surface of the first lens and an image plane of the lens system; f<SUB>2 </SUB>denoting an effective focal length of the second lens; f denoting an effective focal length of the entire lens system.
|
