Film lenses offer better image quality and ease of use than still photography lenses, making them invaluable for filmmakers and cinematographers.
What Is a Film Lens?
A film lens, also known as a cine lens or cinema lens, is a high-end camera lens for cinema cameras or video camcorders that filmmakers, cinematographers and videographers use to make film and digital projects. Like DSLRs and other still photography lenses, a film lens contains a series of glass plates that bring exterior light through the camera’s viewfinder to a film strip or digital sensor.
3 Characteristics of a Film Lens
All lenses filter and focus light so that it hits the sensor or film strip correctly, but there are other factors that determine the look and quality of an image captured by a film lens including:
Focal length: focal length is the distance, measured in millimeters, between the camera lens and the camera’s digital sensor, or film plane, which records the image. Cine lenses with smaller focal lengths have wider angles of view, which is how the human eye perceives the size of the objects in the scene, while larger focal lengths have a narrower angle of view and show less of the scene.
T-stops: The amount of light that passes through the cine lens is measured in increments called transmission stops, or t-stops, which is a more accurate unit of measurement than the f-stop (the camera setting that specifies the aperture of the lens) used for still lenses.
Aperture: The aperture or size of the opening in the lens, or iris, also affects the image that the cine lens can capture. As with focal length, large apertures create a shallow depth of field, which is the amount of focus in the image, while smaller apertures result in greater depth of field and more focus. The widest aperture setting on a lens is called maximum aperture and is ideal for low light situations.
What Are the Main Types of Camera Lenses?
There are two primary types of camera lenses for cinematography and photography:
Prime. A prime lens has a fixed focal length (FFL), so filmmakers must physically move the camera closer toward or away from their subject to change the angle of view. This type of lens is also known as a varifocal lens, meaning its focus changes as it zooms. A cine prime lens is typically lighter than a zoom lens but allows for less creative control over zooming.
Zoom. A zoom lens allows cinematographers to change the focal length and angle of view by zooming in and out with the zoom ring on the lens body. Zooming allows the cinematographer to achieve everything from a wide-angle shot to an extreme close-up. A popular choice for filmmaking is the cine zoom lens, which is a parfocal lensthat allows filmmakers to change the zoom range without losing focus or image quality. Zoom lenses typically contain more glass than prime lenses, which makes them heavier, but allows for greater versatility.
4 Types of Lenses for Filmmaking
There are many lens options for filmmaking within the two primary types of prime and zoom lenses. A representative sample of lens choices includes:
50mm. Known as the “nifty 50,” the 50mm lens is a prime lens that can represent how the human eye sees objects and people in a natural setting. They are both affordable and lightweight, making them ideal for handheld filmmaking. However, first-time users should consider using stabilizers or gimbals (pivoting support for camera operators) for greater image stabilization. A 50mm lens can also create the bokeh effect, a soft, attractive, out-of-focus background image, with maximum aperture. Canon, Tokina, and the Rokinon 50mm T2.1 are among the many 50mm lenses.
Anamorphic. A favorite among filmmakers for its wide aspect ratio (2:39:1) and its ability to produce epic images, anamorphic lenses generate a wide field of view (how much of an image the lens can cover) with only slight distortion and plenty of warmth in the frame. Cooke and ARRI are among the many anamorphic lens manufacturers.
Telephoto. The 75mm telephoto, or long lens, is a zoom lens with multiple focal points that compresses and magnifies details in the foreground, middle ground, and background of an image. The telephoto lens is less frequently used in filmmaking, save for productions with large and extensive sets or locations or documentary’s. Panasonic, Tamron, and Sigma are known for telephoto lenses.
Wide-angle. The wide angle lens is a prime lens with a focal length typically between 14 and 20mm, which is ideal for fitting a large object into the frame or drawing attention to an object in the image’s foreground. Wide-angle lenses can show greater movement and scope within a scene and exaggerate and distort the foreground image. Certain lenses can produce an ultrawide-angle or even fish-eye effect if their focal length is larger than the camera’s sensor size. There are many wide-angle prime and zoom lenses from which to choose: Canon, Zeiss, Sigma, and Fujinon are standard options.
What Are the Differences Between a Cine Lens and a Still Photography Lens?
There are several key differences between lenses used for film and lenses for still photography, including:
Aperture and iris. A key difference between a cine lens and a lens for still photography is the ability to manually adjust many of its functions, including aperture and iris, with rings built into the lens body. The iris rings have t-stop markings, which provide a more accurate measure of light entering the lens, while the aperture ring allows for smoother exposure.
Focus. Unlike still lenses, which adjust focus electronically, cine lenses have a manual focus ring marked with hard stops that allow for smoother focus pulls. The focus ring also allows for more focus throw, which is the degree of rotation from minimum focus distance to infinity; it also cuts down on focus breathing, which is the slight change in focus length when rotating the ring. However, the manual focus also means that most cine lenses do not have an autofocus feature.
Optical performance. In terms of image sharpness, cine lenses provide more consistent quality than still photography lenses. They can handle difficult lighting conditions and have fewer instances of chromatic aberrations, mismatched colors, and vignetting, which is when the corners of an image have reduced saturation.
Size. Cine lenses are larger and heavier in both size and build to still lenses. They typically come with a fixed front diameter that allows the cinematographer to use a variety of cameras, adapters, and accessories, including matte boxes, electro-focus (EF) lens mounts, like the Canon EF Mount, servo controls, and manual follow focus systems, which allow for smoother shifts in focus.
Zoom. The zoom ring on a cine lens creates smoother zooming by changing its zoom focus internally. Filmmakers can zoom in on an object and know that the image will remain in focus.
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