You must have seen this mark on your camera. This is the circle and there is a strike in it. Its work is that it tells the position of your image sensor. If you have not seen, I am telling you. In the picture below, which is visible inside the yellow circle. We call it focal length.
About focal length
Now in this picture, you see this one point, which is called point of conversion. The different point between the conversion and image sensor is called focal lens. It is displayed in MM.
What is point of conversion?
The lens through the light goes inside the camera, So it is converted and we call it the point of conversion. Most of you have seen that the ones with big focus camera have a more focal length.
Like 100-400 mm Meaning is the place for the focal length because these are the movements, so they are made big so that they can easily move in. The lenses which are less focussed like 50mm. They are less focal length, so they are quite small, they move easily, they do not want much space.
Whether you are using full frame camera or using a crop sensor camera, your point of conversion will remain there and the image sensor will be there too, whatever lens you may have in it. Your point of conversion is not multiply.
The distance between the point of conversion and the image sensor is called the focal length. If you put the bean lens in a crop sensor or a full frame camera, then the image sensor and point of conversion will remain in the bean space, then our focal length will also be the bean. But some people say that the focal length becomes multiple.
It does not happen at all. Here’s what changes happen. The angle of view changes here because the full frame is light wide on the sensor in the camera. But Crop Sensor is Narrow. Therefore, it comes with less light. In most lenses, there is a focal length according to the full-frame camera sensor.
The angle of view is wide in the full-frame camera whereas the crop sensor has the angle of view Nero, hence the light comes down, Angle of view changes. Some people consider it to be a multiple of the focal length.