One of the most important parts of a camera is the lenses. It is considered to be the eye of a camera, but have you ever wondered how lenses work and what’s inside the lens? To answer all your queries, we are here with another exciting article, explaining how lenses work in a camera. So stick till the end of the article to get a comprehensive understanding of the inner parts of the lens and their functionality.
Optics Used in Lenses
The sole purpose of a lens is to project the image of your desire on the camera sensor. To accomplish this purpose, a lens comes with different parts, each having a specific role to perform. There is a near identical way in which every lens functions. Most lenses are made of convex and concave lens, or a combination of both. If you are confused about what a convex or concave lens is, then simply put, lenses that are thicker in the middle are convex lenses. On the other hand, lenses that are narrow in the middle are concave lenses.
When light passes through a lens, it bends a little which is called light refraction. To get a full grasp of a lens’s full function, there are some concepts you need to know first.
Focal Length
Focal length is the distance between the center of the lens and the point light after refracting through the lens. Sounds very nerdy, right? If you are already tired of these complex terms, just hold with me for some more time, and it will make sense in a bit.
Now, if you’re wondering why the focal length is important, well, one of the reasons is focal length decides the field of view you get to a lens. For a wide-angle lens, the glass looks much thicker, and the focal length is usually shorter, producing an image of the wide field of view. So, with a wide-angle lens, you can capture your subject along with an adequate amount of background. On the other hand, a telephoto lens looks thinner and comes with a longer focal length, creating a narrower field of view, but it allows you to get close-up shots of your subject.
Focus
Another important job of focal length is it gives you a hint for capturing sharp images. Imagine you had a great scene, and you took a picture, but after getting home, the image was all blurred. So what went wrong there? Well, the problem lies with the appropriate focus distance. When we roll the focus wheel, we’re either moving the lens closer to the sensor or farther from the sensor so that the light that passes through the lens is joined exactly on the sensor and not in front or behind the lens. Failing to place the light coming from the subject on the center will cause you to take blurry images.
Besides moving the whole lens, there is another way of changing the focus distance, and you can do it through the lens aperture. Aperture is like a gateway for light to enter into the lens. When you change the aperture of the lens, the lens opening gets wider or smaller and lets you control the amount of angle of the light entering the lens. A wider aperture allows more light into the lens, creating lesser depth of field and lesser things into focus. On the other hand, narrowing the aperture will cause a greater depth of fill and nearly everything comes into focus but a lesser amount of light.
Chromatic Aberration
All the single glass objects in the world are subjected to chromatic aberration and distortion. When light passes through an optics, the colorways are divided and don’t join on the same point. This results in the colors bleeding off the edges, which is referred to as color aberration. Besides the light passing through the middle part of the lens also doesn’t match up with the light passing through the edge of the lens. This creates a problem called spherical aberration. Both chromatic and spherical aberration can be corrected if a concave lens is attached to a convex lens. It results in converging both light and color rays to converge on a single focal point, creating tack sharp images.
Conclusion
So that was the simplified explanation of how lenses work in the camera. Today’s lens is not confined to optics anymore there are brushless motors linear motors autofocus functionality and shake reduction feature, that have to enhance the usability of a lens further. So if you want a more in-depth article on lenses let us know in the comments.
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