What is the technical meaning of the equivalent focal length of a camera lens?

The equivalent focal length refers to the conversion of a lens on the residual frame sensor to a focal length equivalent to that of a full-frame 35mm sensor.

As for the zoom focal length of the lens itself, it is limited by ** as well as the physical size. 100-400mm is considered telephoto on both sides, compared to 100mm focal length, 400mm is indeed 4 times magnification, but its magnification base is 100mm. It's more sensory than a wide-angle lens of 8-32mm (there shouldn't be one with this focal length in reality, just an example).

20-400mm is not that it can't be made, but how big the objective lens diameter will be, the overall size of the lens, and the pricing after the actual production are also considered. At present, there are 60-600mm lenses on the market, **10,000, and the maximum aperture is limited to f. And the wider the wide-angle end, the larger the diameter will need to be if you don't sacrifice the aperture.

This is not the equivalent focal length, the one you are talking about is the zoom ratio, the zoom ratio of the 100-400 lens is 4, because the focal length of the telephoto end of this lens is 4 times that of the wide-angle end, and it has no other meaning. Moreover, the telephoto end narrows the scope of the picture, not the relationship between zooming in and out. The lens also has a magnification parameter, which depends on whether the subject is zoomed in or down.

As for the equivalent focal length, that's a fuselage format.

Equivalent focal length generally refers to the equivalent full-frame focal length ......

That is, the focal length is converted to a focal length equivalent to 35mm full frame.

This is a different concept from magnifying several times.

Moreover, the focal length of the lens cannot be described by several magnifications.

20-400 shots, it's not difficult to do -400, such shots have been around for ......However, the zoom ratio of this type of lens is too large, and the image quality is average. A truly high-quality zoom lens with a zoom ratio of no more than 3x ......

Equivalent focal length is not a technology, it is a different field of view angle when different sizes of sensors use the same focal length, and the concept of equivalent focal length is introduced for comparison, and it is converted to 35 frames.

Take the Fubaishi GFX50R as an example, X is the DU size of the GFX machine, and the diagonal Zhi is X +, open.

The DAO side is within the Pythagorean definition).

135 full-frame diagonal, G32-64 lens focal length capacity is equivalent to 32 full-frame, 45 lens is equivalent to.

This should be customized according to the size of the medium width, which has a variety of sizes such as 6*6*6 6*7 6*9 6*12 6*17. Take the Pentax 645D, for example. The CCD size is 44*33mm, diagonal 55mm, full diagonal 43mm.

So the conversion ratio is 43 55=. And so on.

Take Fujifilm GFX50R as an example, X is the size of the GFX machine, the diagonal is X+, and the square is the Pythagorean setting.

righteousness). 135 full-frame diagonal, G32-64 lens focal length A is equivalent to 32 full-frame, 45 lens is equivalent to.

Multiply it by how much you can search for on the Internet

The actual focal length of a lens is usually marked on the lens, and the so-called equivalent focal length refers to the focal length of the lens relative to the negative size of the 135 rubber stool and the camera.

Nowadays, the equivalent focal length of a general digital camera is about a double of its actual focal length, such as an 18-135 lens, whose actual focal length is about equivalent to a 135 24-180 or 28-210 lens. Focal length is a measure of the concentration or divergence of light in an optical system, and refers to the distance from the center of the lens to the focal point of light concentration.

What does it mean to be equivalent to a 35mm camera focal length When we talk about the lens parameters of digital cameras, we often have to say the phrase "equivalent to the focal length of a 35mm camera", because "35mm" has become a kind of annotation for us to judge the field of view of the lens.

Equivalent focal length refers to the performance of the angle of view of a lens under different camera specifications, and it is a value calculated by combining the size and focal length of the camera sensor.

This value reflects the actual change in focal length when the sensor size is used as a standard. Here's a more detailed explanation of the equivalent focal length:

1.The concept of equivalent focal length was born in the era of digital cameras, and was used in part to correct with film cameras.

2.For two different cameras with the same sensor size, a lens with a longer focal length has a narrower angle of view, and a lens with a shorter focal length has a wider angle of view.

3.However, when the focal length is considered to be the standard for sensor size family infiltration, the equivalent focal length required with a small sensor such as a mobile phone or mirrorless camera will be shorter than with a large sensor such as a full-frame SLR camera, because the larger sensor has a wider field of view.

4.The equivalent focal length can be calculated by multiplying the actual focal length by the camera's cropfactor, which is the ratio between the sensor size and the standard 35mm film size.

5.Many people think that the equivalent focal length is an incomprehensible criterion, when in fact it is a joint parameter of the lens and the sensor, through which it can better ** the effect of the lens in order to choose the most suitable design and specifications.

6.The calculation of the equivalent focal length is very useful because it can be used to compare the angle of view of different camera lifts and lenses, and to better understand the performance of the lens.

7.For example, if a standard 24-70mm zoom lens is mounted on an APS-C camera, the equivalent focal length of the lens will become 36-105mm. This means that the angle of view of the lens on this camera is not the same as the angle of view of a traditional 36-105mm lens on a full-frame camera.

8.Equivalent focal lengths can also help photographers decide what combination of cameras and lenses to use. If they need a wide-angle field of view, they need a lens with a shorter-equivalent focal length.

9.While the equivalent focal length is useful for photography enthusiasts and novices, professional photographers generally focus on the original focal length values because they have enough experience to ** the performance of the lens.

10.In practical use, we have to keep in mind that using different lenses on cameras of different specifications may produce different effects. Therefore, you need to carefully choose the combination of camera and lens that best suits your shooting needs, and explore and experience different shooting methods in practice.

The focal length of the digital camera lens is always based on the lens of the 135 camera, the main reason is because the 135 camera is the most popular, the article introduces it the most, and people know about it the most. The focal length of the camera is an important indicator to measure the shooting range of the lens, and lenses with different focal lengths adapt to different shooting needs. Lenses with fixed focal lengths are generally divided into wide-angle lenses, standard lenses, and telephoto lenses.

A standard lens is a lens with a focal length approximately equal to the diagonal length of the photosensitive surface (negative, CCD, or CMOS). The angle of view of the subject is very similar to that of the human eye (of course, the afterglow of the human eye cannot be taken into account). For the 135 camera, the size of the photosensitive surface is 36 24mm, and the diagonal length is 43mm.

Because of this, this type of lens with a focal length of about 43mm is a standard lens, and it is customary to use a lens of about 50mm as a standard lens.

The size of the photosensitive surface (CCD or CMOS) of a digital camera varies from camera to camera (135 The photosensitive surface of a camera is fixed). It is difficult to compare the shooting range of different cameras with only the true focal length of the camera lens, so they are converted to the lens focal length of the equivalent 135 camera and then compared.

There are two types of conversion focal lengths, one is a digital camera with a 3:2 aspect ratio for the size of the photosensitive surface, that is, the same aspect ratio as the photosensitive surface of the 135 camera. This type of camera is a camera that can be changed by a DSLR.

The other category is consumer digital cameras, which have an aspect ratio of 4:3 for the photosensitive surface size, which is the same as the aspect ratio of a computer monitor. Most of these cameras are civilian cameras (but a few are DSLR professional cameras, such as the Olympus E-1).

Summary. How is the equivalent focal length of a camera lens calculated? For example, what is the equivalent focal length of 24-70mm?

Hello dear! Because the marked focal length is a physical focal length, it has nothing to do with the frame. The so-called equivalence refers to the size of the viewing angle equivalent to that under the 135-gauge field of view.

For example, the 16mm as the physical focal length you said, as long as it is installed on any camera, the actual focal length of the imaging is 16mm, but because the image sensor of the C-format machine itself is small, the imaging range is relatively small, how much smaller? It's so small that it has the same angle of view as a 24mm lens in the 135 format, so we say it's equivalent to 24mm. However, this equivalence is limited to the size of the viewing angle, and has nothing to do with the perspective relationship.

It's closer to a smaller effect after shooting with 16mm. Hope it helps!

How is the equivalent focal length of a camera lens calculated? For example, what is the equivalent focal length of 24-70mm?

How is the equivalent focal length of a camera lens calculated? For example, what is the equivalent focal length of 24-70mm? Hello dear!

Because the marked focal length is a physical focal length, it has nothing to do with the frame. The so-called equivalent auspicious hand refers to the size of the viewing angle equivalent to the field of view of 135 specifications. For example, the 16mm as the physical focal length you said, as long as it is installed on any camera, the actual focal length of the imaging is 16mm, but because the image sensor of the C-format machine itself is small, the imaging range is relatively small, how much smaller?

It's so small that it has the same angle of view as a 24mm lens in the 135 format, so we say it's equivalent to 24mm. However, this equivalence is limited to the size of the viewing angle, and has nothing to do with the perspective relationship. Closer to that is to shoot with 16mm to the effect of cropping a little smaller after the collapse.

Hope it helps!

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