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Application scope of glass lens
- Aug 13, 2018 -

It is said that lens can transmit light; middle thickness, convex lens; middle thin, concave lens.

A convex lens that converges and acts as a concave lens.

The flat light converges to a point, focus F to represent.

The focus is on the center of the mirror, and the distance is called the focal length of the lens (expressed in F).

Lens in life

The object is close to the camera, reducing the image and handstand.

The object is like a remote projector, magnified and inverted.

The object is the same side magnifying glass, which is erected to enlarge the virtual image.

The image of inverted image is the same as that of the opposite side.

Convex lens imaging principle and Application

The object is imaging at two times focal distance and one or two times focal distance.

The image is inverted and shrinks. This example is used in camera.

Things move nearer, they move farther away, and at the same time they seem bigger.

The object is imaging between one or two times of distance and two times focal distance.

The image is inverted and enlarged. This example is used in projectors.

The object is located in the focus, and the moving screen is not visible.

Looking at objects through a lens, they are erecting a virtual image.

The object and image are on the same side. This example is used in magnifying glass.

The image of the object becomes larger and the image is smaller.

The two times focal length is divided into size and double focal length.


When the object is twice the focal length of the convex lens, the convex lens becomes a real image. "U" at double focal length.

The convex lens is reduced to a virtual image and the object is reduced to two times the focal length of the convex lens (u>2f).

When 2f>u>f, the zoom image is enlarged. The virtual image and the real image that are not reduced are all inverted and there is no empty image.

Eyes and glasses

Myopia lens thick, see near Qingyuan do not see.

The lens of the hyperopia is thin, and it can not be seen clearly in the distance. Before the retina imaging, the concave lens restored to normal.

After the near-optic imaging of the retina, a convex lens is used to clear the light.

The eyes are near 10cm, and the distance is 25cm.

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