What Does the Focal Length of the Lens effect
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In the final picture;
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perspective;
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Blur.
How Does Lens Focal Length Affect the Picture?
Now that you know a bit more about lens focal length, let’s talk about how it affects the picture.
Wide-angle lenses will show landscapes and architecture in all their glory. They will have people appearing in addition to the main subject, with nature and buildings as the main characters.
Normal focal length lenses provide a picture that is close to human perception at the same distance as the subject is from the camera.
Portrait lenses are “sponsors” of beautifully blurred backgrounds. They accentuate the focus on faces and details. The background, in this case, will be fuzzy, but that is exactly the key advantage of portraits. It’s shotted like this that allows you to enjoy the beauty of the person, especially if it’s a scene or individual professional shoot.
A side note! But if the focal lengths of the lenses used are over 105 mm, the resulting photos will zoom in so much that even a child will not fit there.
A related value is the angle of view of the camera, which is influenced by the same focal length of the lens. If the latter has a small focal length, the angle of view will be larger, and vice versa. See a special table to see what the angle of view of the camera will be at different focal lengths.
Focal lengths of the human eye
If we talk about the prototype camera with an optical zoom system, the basic bionic model, which works according to the same scheme and has a focal length, is undoubtedly the human eye. The human eye does a lot of work and is a complex mechanism.
When we pay attention to something, we concentrate on this or that object, another person, or some small thing. We do not even take into account the fact that, at this time, our eyes are doing complex dynamic work: there is an instantaneous evaluation of the distance to the object, its size, and other characteristics.
At the same time, our brain evaluates all the images received from the eyes and finally produces a composite “picture” of what our eyes have seen in a short time. It also depends on a characteristic such as the angle of view. This is why there is a dependence of focal length on the angle of view.
The human eye has a viewing angle of about 150-160 degrees horizontally and 120-130 degrees vertically. The central viewing angle is about 45-60 degrees. If you translate these values into millimeters of focal length, it comes out to about 22 mm.
This is why you can compare the focal length of the human eye with a wide-angle lens. There are some difficulties, though. Because of the specific structure of the eye and its refractive structures, the human eye perceives space and perspective a bit differently (almost like a portrait, normal lens with a focal length of 40-43 mm).
