Wide angle lens and photographing apparatus including the same
View Patent ↗Exemplary embodiments may disclose a wide angle lenses including: a first lens which has a negative refractive power; a second lens which has a positive refractive power; a third lens which has the positive refractive power; a fourth lens which has the negative refractive power; and a fifth lens which has the positive refractive power, wherein the first lens, the second lens, the third lens, the fourth lens, and the fifth lens are in an order from an object to an image, wherein the wide angle lenses satisfy a condition of 0.2<f/BFL 14 <0.25, wherein f denotes an overall effective focal length of the wide angle lenses and BFL 14 denotes a combined back focal length of the first lens through the fourth lens.
1. Wide angle lenses comprising:
a first lens which has a negative refractive power;
a second lens which has a positive refractive power;
a third lens which has the positive refractive power;
a fourth lens which has the negative refractive power; and
a fifth lens which has the positive refractive power,
wherein the first lens, the second lens, the third lens, the fourth lens, and the fifth lens are in an order from an object to an image,
wherein the wide angle lenses satisfy a condition of 0.2<f/BFL 14 <0.25,
wherein f denotes an overall effective focal length of the wide angle lenses and BFL 14 denotes a combined back focal length of the first lens through the fourth lens.
2. The wide angle lenses of claim 1 , wherein the wide angle lenses satisfy a condition of 3.0<f 14 /f,
wherein f 14 denotes a combined focal length of the first lens through the fourth lens.
3. The wide angle lenses of claim 1 , wherein the third lens and the fourth lens form a cemented lens.
4. The wide angle lenses of claim 1 , wherein the first lens is a meniscus lens having a convex surface on a side toward the object, the second lens is the meniscus lens having the convex surface on a side toward the image, the third lens is a bi-convex lens, the fourth lens is a bi-concave lens, and the fifth lens is the bi-convex lens.
5. The wide angle lenses of claim 1 , wherein an aperture is disposed between the second lens and the third lens.
6. The wide angle lenses of claim 1 , wherein the first lens through the fifth lens are formed of optical glass.
7. The wide angle lenses of claim 1 , wherein the wide angle lenses satisfy a condition of EPD≦5 mm,
wherein EPD denotes an entrance pupil distance.
8. A photographing apparatus comprising:
the wide angle lenses of claim 1 ; and
an image capturing device which receives light formed by the wide angle lenses.
9. The wide angle lenses of claim 1 , wherein focusing is performed by moving the fifth lens in an optical axis direction.
10. The wide angle lenses of claim 9 , wherein the first lens through the fourth lens are fixed.
11. The wide angle lenses of claim 9 , wherein the fifth lens satisfies a condition of M 5 <0.3,
wherein M 5 denotes a magnification of the fifth lens.
12. The wide angle lenses of claim 9 , wherein the fifth lens satisfies a condition of Nd 5 >1.8,
wherein Nd 5 denotes a refractive index of the fifth lens.
13. The wide angle lenses of claim 9 , wherein the fifth lens comprises at least one aspheric surface.
14. The wide angle lenses of claim 13 , wherein a surface of the fifth lens, which is disposed on a side toward the object, is the at least one aspheric surface.