Lens and Psychology
"Lensing" or "lensed" are sometimes used to describe the act of a cinematographer shooting a film. It is interchanged with shot, filmed, or photographed. The lens of a film is considered so important to cinematographers that it sometimes can dictate the entire feel of the film. A lens has many properties that show perspective, alter perception, and sometimes create an optical illusion. Field of view, distortion, color, sharpness, color aberration, bokeh, speed, zoom or prime, are just some of the properties of a lens. In the right hands, these properties can create a strong thematic effect. Combined with movement, these effects make movies so fascinating. The choice of lens is one of the strongest tool of cinema to alter perception. It is how the director and/or cinematographer want us to see the movie. As I mentioned in another article, the position of the lens is as important as the lens choice. But in this article I will only focus on the property of the lens itself.
The focal length of the lens can dictate the emotional involvement of the viewer and how the story is viewed in general. The longer the lens, the more compressed the image. The wider the lens, the more it shows the three-dimensional space of the face or object. This can be used, in conjunction with camera position, to show if we are to sympathize with the character or to be distant. Movies recently have been using wide lens near the face, aka the Revenant/ Birdman.
Focal length can also make the face more appealing since it takes away the distortion of the face in certain angles. Most, if not all, beauty shots are filmed with 35mm format and up (standard 35mm Film aspect ratio). Focal length choice can also be used to make a person look horrible. Most recent horror films use wide angle lens near the face to create a more animate reaction. It is as though they are in horror right in front of your face. In the movie, Requiem for a Dream, Mathew Libatique used fish-eye lens to portray the hysteria of the mother character. The lens show how distorted her perception is from reality.
The distortion of a lens can be seen with the rounding of the field of view. More common in wide lenses, it can also be seen through all types of focal length, even in telephoto. This can be observed easily when there are lines within the frame. In a distorted view, the lines within the frame will bend. The edge of the frame distorts more. When shooting a talent with a wide lens, try to avoid their position on the edges of the frame, unless its the desired effect. The face will become distorted and will look very round. This effect gives wide angle lenses its strength in manipulating the image. Be careful using wide angle lenses, specially on situations where the location is very small and a wide shot is needed. The distortion can sometimes be too much and becomes unwanted. It is only used as a strong accent within the language of cinematography.
Zoom or Prime
A lens can either be a variable focal length lens, which is called a zoom, or a fixed focal length, called Prime lenses. While zoom lenses have their advantage by having many focal lengths, it sometimes sacrifices the speed of the lens and being lightweight. Zoom lenses generally are slower, meaning higher in f-stop and thus less light enters, since there are many moving glass material within the lens. Zoom lenses are perfect for television, documentary, films that required the effect of a zoom and the efficiency of having many focal lengths in one lens. It is perfect for a small crew or a camera team that prioritize time for the production. The downsides are its heavy weight and high price. Zooms were more common in the late 1900s. It was used to quick zoom into a subject to create a sense of urgency. Filmmakers today are utilizing the slow zooms to intensify the scene without the audience knowing.
Prime lenses however are only one focal length. This means they are capable of having lower f-stop, thus allowing more light and shallower depth of field. Prime lenses are lighter, shorter, and offer a diverse look in each lens. In bigger productions, the cinematographer will most likely have more than one prime lens. Lenses like the Cooke Super Speeds, Kowa, and Pantar Lenses can offer different personalities among its family lens set. Having worked in a camera rental house, I observed how older lenses with certain characteristics are more in demand than some of the new high end lenses. Lenses like the Arri/Zeiss Master Primes can be considered too perfect of a lens. With older lenses, the imperfections of each lens become a characteristic in the language of film. Effects in post production are not capable of producing some of the effects of these vintage lenses.
The speed of the lens is the ratio of the focal length and the width of the iris inside the lens. It is quantified in f-stop or t-stop. T-stop is "transmission stop", commonly referred to as "true-stop" because it factors the total light loss through the glass and other materials within the lens. F-stop is the ratio that is strictly mathematical and does not factor any other attributes in the lens. Although these numbers are different, they are very close to each other.
The speed of the lens controls two things: amount of light coming through the lens and the depth of field. The wider the iris is, the more light that can enter and the shallower the image plane becomes. The shallower the image plane means better discrimination between the foreground and the background. If the subject focus is in the foreground, the background is out of focus or very blurry with a wider aperture, or lower f-stop. Wide apertures are perfect for low light situations or a subject oriented focus. If you want the subject to stand out in the frame, a wider aperture keeps it in focus while making the background blurry. The narrower the iris, or higher f-stop, less light gets through the lens and the larger depth of field. This means the focus from the foreground and the background are both more in focus. It can cover more depth of field.
Faster speed or wider aperture was needed for Stanley Kubrick's "Bary Lyndon", since the movie was lit with only candles. This required NASA-grade technology to create an aperture sub one. Meaning the aperture opened wider than the length of the lens. Although this solved the exposure obstacle, this was still very difficult to tame. With an aperture at 0.7, the field of depth is very shallow. Subjects have to be in the exact same focal plane to stay in focus. The 1st assistant camera, the focus puller, will have a very hard time tracking focus on such a shallow depth of field. In contrary, Alejandro González Iñárritu's "The Revenant," portrayed deep focus creating a sense of unity between the characters and nature. Nature becomes one of the main characters. This effect is achieved with wide angle lenses and high f-stop, since wide angle lenses also contribute to the deep field of view.
Manipulating the viewer's focus is one of the most important task for the lens and for the director and cinematographer. With a shallow depth of field, the focus is important to convey the meaning of a shot, a scene, and the whole movie. It decides what the audience will see in the conscious mind and in the subconscious. A very skilled director and cinematographer will manipulate background, even in the blur, in which the theme of the film is displayed. Whether it be color, props, action, or scenery. The background creates the world in which the film takes place and give a sense of unity in the thematic strategy of the film. Next time you watch your favorite movies, pay attention more to the background. Nothing in the film is wasted, everything is manipulated to portray the theme of the story. I find it more fascinating finding clues or hidden gems in the background of the shots. I believe this manipulation is what separates the most skilled directors from the rest.
Bokeh/ Lens flare
Bokeh is produced from the shape of the iris. With this shape, blurry lights in the background take shape. Some lenses are known for their bokeh, which can either be desirable or unwanted. Newer lenses have a more perfect circle bokeh while older lenses have different shapes. Shape and quality are the two characteristics of bokeh. Quality is the gradient or brightness distribution within the bokeh. This tool is very nuanced but when used correctly, it can add a more romantic or shocking element to the visual language. You can create your own bokeh by putting a shape cutout in front of the lens. Bring it close enough that it almost touches the front element of the lens.
Lens flare is another lens characteristic in which the light that reaches the lens will spread out into the field of view. With anti-flare coat technology, this is controlled so that the flare is almost minimized. This effect can be used also as a visual tool. Flaring the lens gives the image low contrast, making the image look foggy. This can be used to save the shadows from being lost in data. The most common use of lens flare is the horizontal flare effect with anamorphic lenses. J.J. Abrams uses this excessively in his movies. Again, this is another effect that is very nuanced and only in certain situations this effect is wanted. Lens flares have been used as transitions and shocking the audience with a practical light: flashlights, helicopter light, explosions.
One of the biggest reason to use expensive or cinema grade lenses is to achieve a certain level of sharpness. With higher quality glass and build, the edge detection and the detail of the image are enhanced. Sharp lenses nowadays are a must to aid with the use of green screen and roto-scoping. The post production team needs the sharpest image in order to separate the subject from the background precisely. The smaller movies or movies that don't use heavy post production have the fun of choosing lenses that have a softer or more interesting characteristics: color aberration, and softer lenses. Color aberration is the color infringement in the edge detection within the frame. It might not be too obvious but it adds a look that is unique. Sometimes, too perfect can seem psychologically undesirable. The human perception prefers some error whether in the beat of the music or in their visual field. Imperfection is the ingredient into putting humanism into the visual language. I don't mean that unforeseeable mistakes make good films, I mean controlled imperfection can make a film more relatable and thematically strong.
If I've missed any other important aspect of the topic or provided inaccurate information, feel free to comment or email me at email@example.com. Feel free to share this to your fellow filmmakers who are beginning to understand the tools of cinema. It would help me out a lot.
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