We unpack the design behind Canon’s family of cinema lenses. Read our CN-E lens FAQ with Canon’s Senior Technical Specialist Phillip Reid.
How would you describe a CN-E lens to someone unacquainted?
CN-E lenses are lenses that are made for the Professional video industry and are available in two mount types: EF (all) and PL (zooms only – except for Compact Servo Zooms).
EF mounts are the standard mount type that Canon has been using since 1986. Producing the lenses in this mount makes them flexible as they can be used on a wide variety of bodies and allows for the use of Dual-Pixel Auto Focus on Canon Cinema EOS bodies.
Communicating focal length and aperture settings between Cinema EOS cameras and CN-E lenses is made easy, as well as more advanced features such as the Peripheral Illumination Correction feature, are enabled ensuring consistent colour and brightness across entire image plane.
PL mount has been the Cinema industry standard for nearly all professional body manufactures so it makes sense that Canon would make the lenses with this mount also - but at this time only the Zoom versions are available in PL.
How does it differ from a DSLR lens on its exterior?
The exterior of the CN-E lenses are completely designed for the large range of accessories that are used in the video industry such as focus and aperture controllers. That’s why you see barrels with uniform gear positions on the outside of these lenses. These barrels also have a much larger range of adjustment as demands on fine controls is required in video. The front lens diameter of the CN-E primes are, at 114mm, typically much larger than the L-Series DSLR lenses.
What’s going on inside?
On the inside of these lenses the optical performance is very close to their stills counterparts but the two biggest differences would be the way that the aperture is controlled and measured and the focus barrels have much greater travel distances.
The aperture on a CN-E lens is called a T stop and in a photographic lens it is called an F stop.
T stops are much more accurate and measured as the amount of light at the camera’s image capturing sensor as it is transmitted through the lens.
Still photography does not require this accuracy. The CN-E primes also lack focus and aperture motors as all adjustments are manual.
While EF lenses generally use nine iris blades the CN-E Prime and Zoom lenses use eleven iris blades to enable more natural bokeh.
What type of camera work are they designed for?
Well they are aimed at professional cinematographer/filmmakers but this doesn't mean they are not available to all, it just means that well trained video operators can get the best out of them.
Why do they need to be bigger and heavier than DSLR lenses?
The main reason that they are bigger and heavier is that they are made to meet requirements of control and durability.
The most important thing is that any video team can change lenses no matter what manufacture they are from and the lens will have the same controls in the same position.
Why are they more expensive?
Build quality. The materials needed to meet the requirements of the video industry just simply cost more and they are designed to be used day-in day-out on long days shooting out in the elements. Cinema lenses offer significantly less “lens breathing” during focusing and cinema zooms are parfocal which makes them more expensive to manufacture.
Do you need a CN-E lens to shoot cinema work?
I think the answer to this would depend on the type of production and the “look” the cinematographer was after. The cinema lenses definitely produce a distinctive image but may not always be suitable of the work at hand.
Low budget video production may well benefit from lighter lenses but their controls will be limited.
Can you use CN-E lenses on a DSLR?
Yes you can.
How many focal lengths are there in the Canon CN-E range?
My understanding is that there are seven fixed lenses (14mm, 20mm, 24mm,35mm, 50mm,85mm & 135mm) and 12 zoom lenses but of course Canon is always releasing more.
How are Canon CN-E lenses unique to the broader cinema lens range in other brands?
Good question, I believe that you would choose a Canon over another for the quality of the colour and contrast produced by these lenses.
Also you may choose a Canon for how it renders the background of an image just as much as the subject. Canon’s long-term legacy in lens manufacture has been used and trusted for over 60 years within the broadcast market. Since entering the cinema market in 2012 they now have a complete range of cinema lenses designed to meet to needs of contemporary 4K filmmakers.
With contributions by SUNSTUDIOS motion specialist Neale Head.
Don’t be fooled by appearances. In the case of the Canon EF 70-200mm f/2.8L IS USM II and III, comparing the two lenses side-by-side, you could be forgiven for thinking not much has changed between models.