One might assume that all lenses are interchangeable and you can simply adapt any lens to suit your needs. However, it is not true. Cinema lenses and traditional lenses are very different and cannot always be interchangeable. Cinema lenses (also known as cine lenses) are designed and built for use on a motion picture camera while traditional lenses (also known as still lenses) are designed and built for use with an SLR still camera.
Following are some of the key differences between cinema lenses and traditional lenses:
Size and Cost
Cine lenses are relatively larger than traditional still lenses. They are heavier than the still lenses so they may be relatively more difficult to travel with. Apart from this, cinema lenses are also much more expensive. Generally, cine lenses cost four to five times more than still lenses.
If you have only ever used still lenses, then the first thing you will notice when using a cine lens, apart from its larger size, is its gears. Cine lenses are generally geared for both changing the aperture and pulling focus. With traditional lenses, the aperture is electronically controlled by the camera. With cine lens, you can manually change the aperture and it is also relatively smoother, so you can be more precise.
Most traditional lenses suffer from lens breathing. Lens breathing is when you change the lens focus, the lens zooms in and out a little and the field of view changes. Cine lenses generally have less lens breathing, which is basically how much is in then field of view. On a traditional still lens, the lens breathing can be quite distracting, especially when you are trying to focus between two objects. On the other hand, cinema lenses have little to no lens breathing on the frame’s edges when changing focus.
T/stops and F/stops
Another key difference between traditional lenses and cine lenses are F/stops and T/stops. F-stop is the ratio between the focal length of the lens and the diameter of the aperture. When the focal length is changed, the amount of light that hits the sensor changes, even if all the camera settings (including aperture) stay unchanged. With T-stops, the light being transmitted to the camera’s sensor is measured.
Cine lenses have better controlled chromatic aberration as compared to traditional lenses. So, when you are using a cine lens, you will see more consistent edge to edge sharpness and less barrel distortion, particularly at wider angles.
All in all, there are several key differences between cinema lenses and traditional lenses. What type of lens you use depends on the purpose of your specific shoot. Sometimes it is necessary to use a relatively smaller and lightweight still lens on a more traditional camera. Alternatively, you may require some of the qualities of a cinema lens if you are going to be racking focusing or zooming in the shot. At the end of the day, a lens is a very important tool and you should always use the best tool for the job.