What is the relationship between object distance and image distance and focal length? What is image

Object distance: U image distance: V

Focal length: f relationship: 1 U + 1 V = 1 F

The most basic Gaussian imaging formula in optics: 1 u

1 v1 f, i.e., the reciprocal of the object distance plus the reciprocal of the image distance is equal to the reciprocal of the focal length.

Secondly, please understand the causal relationship between objects and images, and that there are objects that have images. Different object distances correspond to different image distances, but not the other way around. If you set an image distance yourself, you won't necessarily find the corresponding object distance, which means that the image distance you set won't be imaged at all.

For convex lens imaging (cameras are convex lens imaging), the object-image relationship is as follows:

When the object distance is infinity, the image distance is equal to the focal length, and the image is in the focal plane (when the camera focuses on infinity);

When the object distance is between infinity and two times the focal length, the image distance is between the focal length and the two times the focal length, forming a reduced real image (this is generally the case with cameras, and macro shooting is the case when the object distance is close to two times the focal length);

When the object distance is equal to twice the focal length, the image distance is equal to the object distance, and the object image is equal to the large, and the 1:1 macro is the case;

When the object distance is less than twice the focal length and larger than the focal length, the image distance is greater than twice the focal length, and it becomes a magnified real image (this is the case with slide projectors and movie projectors, and compared to cameras, a small number of macro shots, such as Minolta's 1x-3x macro and Canon's 5x macro shooting);

When the object distance is equal to the focal length, the image distance is infinite, and the light rays on the object are parallel rays after passing through the lens, and are not imaged;

When the object distance is less than the focal length, the image distance is negative, i.e., it is a virtual image on the same side of the object (this is the case with magnifying glasses).

Obviously, the image distance is determined by the object distance and the focal length, and it is not possible to form a real image if the image distance is less than the focal length.

The image distance is the distance between the image formed by the object through the plane mirror and the convex lens, and the object distance is the distance between the object and the convex lens.

The focal length is the distance between the object and the convex lens when the object passes through the convex lens into an image of equal size, and the object distance is equal to the image distance, and the object and the image are equal to the size.

At this time, it is obvious that the object distance is much greater than twice the focal length, so the image distance must be much less than twice the focal length but must be greater than double the focal length, so choose C

Note: If the object distance is denoted by f1, the phase distance is denoted by f2, and the focal length is denoted by f, then:

If 2F F1 F, it is a magnified handstand virtual image, F2 2F (projector);

If f1 is greater than 2f, it is a reduced handstand, 2f f2 f (camera);

If f1 f, it is an equal inverted virtual image, f1=f2;

If f1 f, it is an upright magnifying real image (magnifying glass).

On both sides of the object, on the same side of the object, all upside-down images are virtual images, and upright images are real images.

How serious? I can't spare you if you don't give you points?!

The relationship between object distance, image distance, and focal length is as follows:

1. When the object distance is greater than 2 times the focal length, the image distance is between 1 times the focal length and 2 times the focal length, and it becomes an inverted and reduced real image. At this time, the image distance is smaller than the object distance, the image is smaller than the object, and the object image is on the opposite side.

2. When the object distance is equal to 2 times the focal length, the image distance is also 2 times the focal length, forming an inverted and equal size real image. At this time, the object distance is equal to the image distance, the image and the object are equal in size, and the object is on the opposite side.

3. When the object distance is less than 2 times the focal length and greater than 1 times the focal length, the image distance is greater than 2 times the focal length, and it becomes an inverted and magnified real image. At this time, the image distance is greater than the object distance, the image is larger than the object, and the image is located on the opposite side of the object.

4. When the object distance is equal to 1 times the focal length, it will not be imaged, and it will be emitted as parallel light.

5. When the object distance is less than 1 times the focal length, it will become an upright and magnified virtual image. At this time, the image distance is greater than the object distance, the image is larger than the object, and the object image is on the same side.

1. Focal length is a measurement method in the optical system to measure the concentration or divergence of light, which refers to the distance from the center of the lens to the focus of light concentration when the parallel light is incidentified; The object distance refers to the distance from the object to the optical center of the lens; Image distance is the distance between the image and the flat mirror (or the optical center of the lens).

2. Focal length. 3. Focal length, also known as focal length, is a measure of the concentration or divergence of light in an optical system. It is also the distance from the optical center of the lens to the imaging plane such as the tintle or CCD or CMOS in a camera.

Optical systems with short focal lengths have a better ability to concentrate light than those with long focal lengths.

4. Object distance. 5. For the lens, the plane that passes through the optical center and is perpendicular to the optical axis coincides with the main plane of the object and the main plane of the image side. There is a conjugation relationship between object distance and image distance, and the farther the object distance, the closer the image distance. Conversely, the closer the object is, the farther away the image is.

Strictly speaking, the object distance should be the distance between the plane of the subject and the main plane in front of the lens.

6. Like a distance formula.

7. One double focal length is divided into virtual and real, and two times the focal length is divided into size.

8. The near image of the object becomes larger, and the distant image of the object becomes smaller.

Focal length (f) - The distance from the focal point to the center of light is called the focal length.

Object distance (u) - the distance from the object to the optical center of the convex lens is called object distance!

Imaging distance (v) - the distance from the image formed by the convex lens to the optical center of the convex lens is called the image distance!

Focus (f) - the light rays that pass through the convex lens and are parallel to the main optical axis, and the convergence point on the main optical axis is called focus f!

Extended Materials. Convex lens (convex lens) can image, and when a convex lens is used as a camera lens, the clearest image it produces generally does not fall exactly on the focal point, or in other words, the distance from the clearest image to the center of light (image distance) is generally not equal to the focal length is stupid, but slightly larger than the focal length. The specific distance is related to the distance between the illuminated object and the lens (object distance), the larger the object distance, the smaller the image distance, (but in fact it is always greater than the focal length).

In a thin lens in air, the focal length is the distance from the center of the lens to the main focal point. For a converging lens (e.g. a convex lens), the focal length is positive, and a beam of directional light will converge at a single point. For a divergent lens (e.g., a concave lens), the focal length is negative, and a beam of parallel light spreads out after passing through the lens.

(1) The size of the object and the image are represented by y and y, respectively, which can be obtained from the geometric relationship in the figure. yy′=u?ff=fv?f

then gets: (u-f1

v-f2=f1f2

After simplification, the formula for object image distance is obtained, that is, the relationship between u, v, f1, and f2: fu

fv is the angle of incidence, 2

For the corresponding exit angle, the refractive index n of the lens is given for the angle between the light rays in the parallel plate and the normal, which is obtained by the law of refraction.

n1sinθ1

nsinγ=n2sinθ2

To paraximal rays, 1

It's all very small, and it gets sin 1

1，sinθ2

2, thus getting:

nn(3) The incoming ray from the object point Q to the center O should be emitted to Q after refraction by L, as shown in the figure below

In the condition of the paraximal axis, there is. yu

tanθ1θ1，y′

v=tanθ2

Divide the two formulas and utilize the formula, to get. y′uyv

y y=f with the formula nn

u?f substitution, get: fu

u?f)v=nn

i.e. f1=nuvn

y y=v?f

f substitution, get:

v?f)ufv

nn stands for f2=nuvn

U+nv thus yields f1, f2, n1, n2

relational formula. ff

nn answer: (1) At this time, the object distance is u, the image distance v, and the focal length f1

The relationship between F2 is fu+f

The angle 2 between the outgoing ray and the main shaft corresponding to v(2) is nn(3)f1,f2,n1,n2

The relationship between the four is ff=nn

In physics, you is the object distance, f is the focal length, and v is the image distance.

In physics, u-object distance refers to the distance from an object to the optical center of a lens.

V-Pitch is the distance between the image and the flat mirror (or the optical center of the lens).

f focal length is a measure of the concentration or divergence of light in the optical system, which refers to the distance from the center of the lens to the focal point of light concentration when the collimated light is incidence.

Physics: Physics is the study of the most general laws of motion and the basic structure of matter. As a leading discipline in the natural sciences, physics studies the most basic forms and laws of motion of all matter, from the universe to elementary particles, so chaos has become the basis for the research of other natural sciences.

Physics began in the days of Galileo and Newton, and it has become a fundamental science with many branches. Physics is an experimental science, and it is also a science that advocates rationality and attaches importance to logical reasoning.

The formula for convex lens imaging: 1 U+1 V=1 f, where u represents the object distance, V represents the image distance, and F represents the focal length.

In the case of a concave lens, the focal length of a concave lens is expressed as a negative numerical value because it has a divergent effect on the light, and the intersection of the reverse extension line of the divergent light is called the imaginary focus of the concave lens. In the same way, the image distance of the virtual image should also be expressed as a negative number.