What are Camera Lenses?
The lens of a camera is the part of the camera that helps to focus the light to a fixed point. What the lens does is to focus the light it has been exposed to a sensor or film. Camera lenses are located at the front of the camera and they consist of a set of curved glasses (convex or concave) that function to focus the light in specific and different patterns.
While the curved glasses in the lens aid with focusing the light, there are other parts of the lens that contribute to overall efficiency of the lens. Some of the Important features in a lens include
The way a lens takes in light is through an opening that opens for a specified period. This opening is called the aperture(1) and it also plays a part in the amount of light rays the lens will direct to the film strip. Apertures are indicated with f-stops.
These f-stops numbers give an indication on how large the aperture opening will be during a footage capture. Generally, the larger the f-stops number, the smaller the opening and vice versa. Also, apparently, a wider aperture will take in more light compared to a small one. However, with video camera lenses the t-stop is the true measure of light the lens takes in.
One of the most important functions of the aperture in relation to the camera lens and the camera in general is the determination of the Depth of Field. The depth of field in a footage refers to the amount of objects in focus. A deep depth of field will focus on more things than a shallow depth of field. This feature is very important for filmmakers because they use it to convey messages to the audience.
The relationship between the f-stops and depth of field is positive. Simply put, the higher the f-stops, the deeper the depth of field and vice versa.
2. Focal length
The focal length of a lens refers to the distance between the converging point of light on the lens and the sensor that reads the images. This feature is important because it gives users information on the width of light the camera can capture. Focal length is measured in millimeters and increase in the focal length results in a narrower field of view, hence less image on the screen.
Focal length and aperture are completely different things although people tend to mix them up. For emphasis, focal length tells users the width of light the camera processes while the aperture indicates the amount of light (clarity) the lens directs to the sensor. However, the focal length in combination with the f-stops determine the types of camera lenses and quality of lenses that are available for use.
Classification of Camera Lenses
Every type of camera lens falls under two categories and this categorisation is done based on whether the focal length is fixed or not. The classifications are:
- Prime Lens
Prime lenses came first and because of that, have a fixed focal length. Since a varying focal length is the reason a camera can zoom in or out on a subject without the user moving, using this lens requires the individual to physically move closer or farther away from the subject when there is a need for zoom.
Even without the auto zoom, this class of lens has its benefits. One of the benefits is the advantage of achieving better focus at faster periods than its counterpart, therefore producing a better image quality. In addition, the fixed focal length means less glass compartments for zoom which also translates to a light and durable lens. Finally, prime lenses usually have a wide aperture range which is great for depth of field and low light shooting. Here are some of our best lenses for low light.
The focal length (s) of a lens is valued with respect to the sensor size in the camera. All the lens focal lengths described in this article are for a full frame sensor. There are other sensor sizes with corresponding focal lengths to achieve the same kind of picture.
- Zoom Lens
Zoom lenses are the opposite of Prime lenses in the sense that they have variable focal lengths through the aid of different lenses. These kinds of lenses are usually the ones that come with the camera (kit lens).
Depending on the focal length range, users can enjoy powerful zooming functions although it comes at the cost of being slower and losing focus a bit compared to the prime lens. In addition, zoom lenses are bigger and bulkier due to the extra lens components. Furthermore, in contrast to prime lenses, zoom lenses have small aperture range and therefore do not have large depth of field.
Types of Camera Lenses
Lenses come in different types and these types of lenses are all under the two classifications described above. On a general note, lens types are mostly distinguished by the focal length(s).
The same way each type of camera has its own merits, so does every lens. Each type of lens has its best use cases. Although some lenses are more widely used than the others, being creative as a videographer or photographer can help individuals achieve excellent shots with any kind of lens. You can also learn how to clean a camera lens without a cleaning kit.
Here are some of the most popular lenses for SLRs and DSLRs, mirrorless or video cameras.
This type of lens is best for close-up shots because it captures the subject in a very detailed way. It is usually used to capture small subjects and for still photography but there are still scenarios where videographers employ this lens to convey details. Additionally, this lens is usually used for nature photography, product adverts among other uses. The focal length is usually in the range of 45 – 200mm for a full frame sensor(2).
Also read: What is Macro Lens
Just like with a telescope but with a limited range. Telephoto lenses are adapted for capturing subjects that are far away. Telephoto lenses are characterized by a large focal length rating which means it has a narrow field of view. In fact, telephoto lenses can have focal lengths larger than 600mm for a full frame sensor.
In a way, the larger the focal length, the narrower the field of view, and the farther the lens can capture the subject. These lenses are especially good for wildlife and sports photography.
The subset of telephoto lenses include super-telephoto lenses and medium-telephoto lenses. The telephoto lenses are not common with videographers but the mild ones are sometimes used for shots from a distance e.g from a helicopter or from the top of a building.
This is the most common type of lens available out there. The focal length hovers around 50mm for a full frame sensor. This lens is quite popular with cinematographers and the general public because it is believed to be the best replica of what the human eye detects. Also, this lens has a large use case and can be used by videographers or photographers of any expertise level.
The perfect combo for a lot of videographers is a prime standard lens. This kind of lens produces sharp pictures at a normal viewing angle. Standard lenses are not good for close up photography as well as long distant photography but can handle anything in between as long as the user wants a normal frame length.
The anamorphic lens is particularly popular with cinematographers because of the wide aspect ratio. It is the film industry standard for a video camera lens. This lens is able to produce what the populace enjoy as the ideal film viewing screen without sacrificing any pixel to cropping. Furthermore only this lens can produce this wide aspect ratio in its natural state.
The anamorphic lens is not an everyday lens of a photographer because it attracts quite a price but it is the best at what it does.
As the name implies, these are lense that give a wider than average field of view. It is an adequate video camera lens in the absence of the anamorphic lens. From the focal length lesson with respect to the field of view, wide-angle lenses have low focal length readings. At least lower than that of the standard lens. These lenses are usually in the range of 24mm to 40mm for a standard sensor size. This sensor is especially useful to cinematographers when filming a full scene or in a tight space.
A prime wide angle lens gives a lot of videographers the sweet spot when filming. The larger depth of field ensures that every detail is captured even in a wider than average field of view.
Taking the wide angle lens up to a notch will produce a super wide-angle field of view. An example of a super or Ultra wide-angle view is the fish eye lens with focal length less than 14mm. With small focal lengths like this, the viewing angle becomes so wide that the horizon starts to curve in.
Although wide angle lenses are adopted during filming, Ultra wide angle lenses have less use in cinematography.
There are still some other lenses popular with photographers but are not popular with videographers. Examples of these kinds of lenses include the infrared lens and the tilt-shift lens.
Making music videos is all about being creative. With that said, any lens can be used to make music videos although it will be more suitable to use some than the others.
Most cameras come with what is referred to as a kit lens. Kit lenses are usually medium quality zoom lenses with an average focal length and aperture range.
The types of camera lenses we have gives users a lot of options, although the options are more limited for cinematographers. It is quite obvious video camera lenses and camera lenses in general help videographers to portray information to their audience. Hence the need to know the type of lenses applicable.
Which lens type is your favorite? Which one do you consider the best? Feel free to tell us in the comments.
- Nasim M. (2020 April). Understanding aperture in photography. Retrieved from https://photographylife.com/what-is-aperture-in-photography
- Jackie D. (2013 Oct). Demystifying digital camera sensors once and for all. Retrieved from https://www.techhive.com/article/2052159/demystifying-digital-camera-sensors-once-and-for-all.html