When it comes to buying camera lenses, some are better for photography and some are better for cinema. Choosing a particular lens an aesthetic decision, based on your needs as a filmmaker. So you will want to become friends with the cameral rental house, rent some lenses and then run a lot of tests.
To start the process, you’ll need to know the camera sensor size and the specific lens mount for your camera body.
The sensor is the part of your camera that translates the image you see into the 1’s and 0’s of digital video. Filming in different resolutions actually effects how much of the sensor is in use. My Sony A7S II for example, has a full frame sensor but the full sensor is only being used when I film in 4k resolution. If I were to shoot in 1920 x 1080 I would only be using a portion of the sensor for the capturing of the image.
Keep sensor size in mind when you buy a lens.
I made a mistake of buying a really nice Zeiss zoom lens for my camera and was dismayed to discover that when shooting in 4K there was a heavy vignette around the image. This is because, I didn’t buy a full frame lens. A full frame lens allows the image to cover the entire surface area of the sensor. A non full frame lens only allows the image to cover a portion of a full frame sensor.
When you look through a lens that is meant for a smaller sensor you will actually see the inside edges of the lens which are black. If you were to use a full frame lens on a smaller sensor you will not be capturing the full image. Know what sensor size you have and then buy camera lenses designed for that sensor.
The Minimalist Guide to Camera Lenses (For Filmmakers)
The lens mount is how your lens locks onto your camera.
Different companies make their cameras with specific mounts. Sometimes you can order your camera body with the mount you want but if not, don’t fret! There are companies that make excellent adaptors to fit most any lens to any camera.
My Sony A7S II has a Sony E-Mount receiver. This means that when I buy camera lenses I need to be sure to buy one that has this type of mount. And since I mostly use my equipment for making films so it was important to me to find cinema style camera lenses.
One attribute of a cinema lens is that it has ‘teeth’ around the focus ring and the aperture ring. These ‘teeth’ can be combined with a follow focus to allow the AC (Assistant Camera) to pull focus during a shot. Cinema lenses also tend to have a larger amount of pull needed to adjust focus. This is very useful when filming, as a tiny focus pull can be much more challenging to get right during a shot.
A prime lens is a set lens as opposed to a variable lens, (zoom lens).
The advantage of a prime lens is that the image generally is sharper and exposure does not require as much light as a zoom lens. A zoom lens is a long tube and the glass elements can be slid closer or further apart to change the lens size. A variable lens is extremely useful in a fast paced scenario but it does require more light. A variable lens is helpful in run and gun situations.
When buying camera lenses, sharpness is also an important consideration. Sharpness is determined, in part, by the quality of the glass and how that glass is ground to create the lens. I choose five lenses made by a Korean company called Rokinon. These lenses are relatively cheap but the craftsmanship and the quality of the image they produce is impressive.
The 14mm lens creates unbelievably wide images and allows you to get a shots in a small work area. The 24mm lens is still fairly wide angle but it creates an image that looks more normal to the eye. And the 35mm lens is known for the Hollywood close up. If someone says they are ready for their close up, grab this lens.
If you’re looking for a much narrower field of view, the 50mm and 85mm lenses are the way to go. These telephoto camera lenses are great for capturing a fine detail or an extreme close up. Just keep in mind that a telephoto lens will also have a much shorter focal length. (The focal length is the amount of distance that you can have in focus at one time.) A short focal length is fantastic for when you want the back ground to be much more out of focus than your subject.
Like all aspects of filmmaking, the creative decisions you make both in terms of camera lenses and gear should always serve the story.
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John Graham is an LA based filmmaker. His feature films ‘Home Sweet Home’, ‘Catching Faith’ and ‘Wish For Christmas’ are available in the USA and world wide. John attended the Savannah College of Art and design, where he graduated Magna Cum Laude with a BFA in Film and Television. Check out his website or instagram for more.