What is a focal length preset, what is a camera focal length and how to accurately determine the mai

Is it the Depth of Field feature?

I also saw the book today by Brian. Peterson's "Understanding" lol.

Turn off Safe Manual Focus in the menu and turn on Manual Focus mode.

Hello, you can adjust it automatically.

Yes, you can set parameters such as focal length zoom, white balance, **compensation, etc. Then 3 sets of data can be stored.

It can be called directly when it is to be used.

mm is the focal length of how many millimeters, note that the focal length and image distance are not the same. What is the focal length you need to look through the physics textbook, the parallel rays at infinity have a focal point after passing through the lens, the distance from this focus to the center of the lens is the focal length, the focal length of the convex lens is a solid point, and the focal length of the concave lens is an imaginary point.

The lens label such as 18-55mm means that this is a zoom lens, and the focal length of the lens can be changed from 18mm to 55mm.

There is also a concept of focusing range, that is, the camera can shoot objects in this range, for example, the wide-angle end shooting range is infinite, which means that this camera can shoot objects at infinity from the camera, and if the object is at meters, it cannot be clearly imaged on the photosensitive chip, which is mainly related to the distance travel between the lens controlled by the camera and the negative.

As for the back of the lens, it refers to the aperture size, the larger the aperture, the smaller the value, for example, the aperture is larger than the aperture, the definition of aperture is: the focal length divided by the size of the lens clear aperture to get the value, for example, the focal length of the lens is 300, and the diameter of the clear aperture of the lens is 30, then the aperture value is f=300 30=10

The larger the clear aperture, the more light that hits the bottom film, and the shorter the time required, which is the principle that a large aperture lens can shoot clearly with a high-speed shutter. For example, if you fill a glass of water, the larger the faucet, the shorter it will take to fill up.

I don't know, so you can explain it to you, can you understand it.

The understanding of focal length is correct, but the actual camera lens is not optimized for directional light; Directional light is fine with a monocle.

The focal length is the distance from the center point of the lens to the plane of the sensor. The concept of focal length does not need to be remembered. Just remember the two characteristics of focal length – angle of view, perspective.

Focal length vs. angle of view.

Each lens has its own focal length, and the shooting range varies depending on the focal length. To put it simply, the shorter the focal length (the smaller the number), the wider the range of the shot frame; The longer the focal length (the higher the number), the narrower the range of the captured frame, similar to a telescope.

The distance from the lens to the point where the light is concentrated.

To put it simply, for a camera, the focal length is the distance from the focal point of a set of directional light passing through the lens group of the lens to the center of the lens group of the lens.

, then the number that follows is usually its focal length, that is, the focal length length. Such as:"f=8-24mm，38-115mm(35mm equivalent)"

This means that the focal length of this camera is 8-24mm

At the same time, the angle of view of the diagonal is equivalent to the focal length of 38-115mm of a conventional 35mm camera. Generally speaking, the standard lens focal length of a 35mm camera is about 28-70mm, so a focal length higher than 70mm means that the telephoto effect is supported, and a focal length lower than 28mm means that it has the ability to shoot wide-angle shots.

Focal length is the distance from the center of the lens to the focal point. The focal length of a lens is divided into image-square focal length and object-square focal length. The focal length of the image square is the distance from the main surface of the image square to the focal point of the image square, and similarly, the focal length of the object side is the distance from the main surface of the object to the focus of the object side. Focal length schematic.

The camera has a button to adjust the focal length, which is generally in the outer ring of the camera, you turn it down to see, it may be that when you are in the store, the position is just adapted to the focal length, and when you get home, the position changes, but the focal length is not adjusted, so it is naturally not clear.

What about the light??? Try adding lighting. If your so-called bad effect is a lot of noise or pigmentation, it should be a problem with lighting. If it's blurry, it's a focal length issue.

You think too much Resize can only be moved back and forth.

Generally, the monitoring probes that can adjust the focus are 2000+.

This gadget can't be

Answer: The focal length of the camera refers to the distance from the center of the lens to the focal point, the lens of the camera is a group of lenses, when the light parallel to the main optical axis passes through the lens, the light converges to a point, this point is called the focal point, and the distance from the focus to the center of the lens (that is, the center of light) is called the focal length.

The focal length of a lens is divided into image-square focal length and object-square focal length. The focal length of the image square is the distance from the main surface of the image square to the focal point of the image square, and similarly, the focal length of the object side is the distance from the main surface of the object to the focus of the object side. It is important to note that due to the extensive use of telescope structures in camera lens design, especially in zoom lenses, the focal length of the object and the focal length of the image are not necessarily equal.

When we talk about the focal length of a camera lens, we mean the focal length of the image square.

As an important parameter of the camera, the focal length is often encountered on the lens of the SLR camera, but its impact on the image has always stayed in a sensory understanding, the focal length can be clearer in the long run, and the focal length can be seen clearly in the short distance. The length of the focal length of the lens determines the size of the subject imaged on the imaging medium (film, CCD, etc.), which is equivalent to the scale of the object and the image. When shooting at the same target at the same distance, the image with a long focal length is larger, and the image with a short focal length is smaller.

Resizing can only be controlled by adjusting the distance between the camera and the face.

The camera is related to the lens you choose, generally, 4mm, 6mm, 8mm, the larger the lens, the bigger the blind area. It is related to the distance, do not adjust the focus, it is easy to lose focus.

u>2f f2f into a handstand to zoom in on the real image.

UF indicates the focal length of the lens.

u denotes the distance between the object and the lens (referred to as object distance).

Pitch is the distance from the image of the object being imaged to the lens (principal plane).

Principle: Concentrate light, have focus, so imaging. Regularity:

If the object distance is greater than twice the focal length, it will become an inverted and reduced image. The object distance is equal to twice the focal length, and it becomes a large image such as an inverted stand. If the object distance is less than twice the focal length but greater than one time the focal length, it becomes an inverted magnified image.

The object distance is equal to one time the focal length, and it is not imaging. The object distance is less than one time the focal length, and the virtual image is magnified upright. Except for the last one, all of them are real in front.

Elephant distance is the distance between the image and the lens made of a convex lens. It can be changed.

The focal length is the point at which parallel rays converge after being refracted by a convex lens, and the focal length is immutable.

The image distance is the distance between the image and the lens made of a convex lens, which can be changed at will. Changing the image distance can change the size of the image and stand upright.

The focal length is the point at which the parallel rays converge after being refracted by the convex lens, which is a property of the lens itself, which is fixed and immutable.

The focal length is fixed by a convex lens, which is the distance from the focal point of this convex lens to the convex lens. Whereas, the image distance is the distance from the image to the convex lens, and the image distance changes with the change of object distance (the distance from the object to the convex lens). Suffice it to say, focal length and image distance don't have much to do with each other.

The focal length is fixed and the image distance is not fixed.

For convex lenses, the parallel light emitted from one side at infinity and perpendicular to the mirror surface will converge with one point on the other side of the convex lens, which is called the focal point of the convex lens on this side (if the curvature of the two mirrors of the convex lens is different, the focal points of the two sides of the convex lens are asymmetrical), and the distance from the focal point to the center of the mirror is the focal length.

The light emitted by a specific luminaire is generally not parallel light, but if the luminaire is very close to the main axis (the line that passes through the center of the convex lens and is perpendicular to the mirror), it can be imaged on the side of the convex lens (it can be a real image or a virtual image, which is determined according to the distance between the object and the mirror and the curvature of both sides of the convex lens), and the distance between the image and the mirror is the image distance. Even if there is a focus on the image, the meaning is not the same.

It's a conventional standard.

The focal length of the equivalent 135mm camera is 24-36mm for the wide angle, the equivalent focal length of 14-24 is the ultra-wide angle, and the focal length below 14mm is the fisheye.