Optical system
An optical system includes a first lens having negative refractive power and having two concave surfaces, a second lens having positive refractive power, a third lens having refractive power, a fourth lens having refractive power, a fifth lens having refractive power, a sixth lens having refractive power, and a seventh lens having refractive power. The first to seventh lenses are sequentially disposed from an object side.
1. An optical system comprising:
a first lens having a negative refractive power;
a second lens having a positive refractive power;
a third lens having a positive refractive power;
a fourth lens having a refractive power;
a fifth lens having a negative refractive power;
a sixth lens having a positive refractive power; and
a seventh lens having a negative refractive power,
wherein the first to seventh lenses are sequentially disposed from an object side of the optical system toward an image side of the optical system, and
53°<ANG/Fno<61° is satisfied, where ANG is a field of view of the optical system and Fno is a constant indicating a brightness of the optical system.
2. The optical system of claim 1 , wherein ANG≥90° is satisfied.
3. The optical system of claim 1 , wherein the first lens has a concave object-side surface.
4. The optical system of claim 1 , wherein the second lens has a convex object-side surface.
5. The optical system of claim 1 , wherein the third lens has a convex object-side surface.
6. The optical system of claim 1 , wherein the fourth lens has a convex image-side surface.
7. The optical system of claim 1 , wherein the fifth lens has a concave object-side surface.
8. The optical system of claim 1 , wherein the fifth lens has a meniscus shape in which an object-side surface of the fifth lens is concave and an image-side surface of the fifth lens is convex.
9. The optical system of claim 1 , wherein the sixth lens has a convex object-side surface and a convex image-side surface.
10. The optical system of claim 1 , wherein the seventh lens has a meniscus shape in which an object-side surface of the seventh lens is convex and an image-side surface of the seventh lens is concave.
11. The optical system of claim 1 , wherein the seventh lens has an inflection point formed on either one or both of an object-side surface of the seventh lens and an image-side surface of the seventh lens.
12. The optical system of claim 1 , wherein an object-side surface and an image-side surface of each of the first to seventh lenses are aspherical.