ULTIMATE GUIDE TO LENSES
CINE PRIMES
If you demand the ultimate quality above all else, then a dedicated cinema prime lens should be top of your shopping list. It’s no coincidence that virtually all big-production movies, fromHollywood blockbusters to Netflix series dramas, are shot on matched sets of primes chosen for their light-gathering qualities and the distinctive look they can give to a film. The very top-end manufacturers like Cooke offer their primes with different ‘looks’ they can give, from crisp and contrasty to flarey and vintage. Even Sigma has got in on the act with its new range of Classic primes. Then of course there are expensive, anamorphic lenses to give that Cinemascope super-wide look, unique oval bokeh and long horizontal flare streaks. If you have very deep pockets, then many manufacturers offer very pricey options that appease every creative whim. But for the majority of independent filmmakers who are considering a set of primes, then the best are neutral, multi- purposes lenses with good control of flare. And there are lots of options at lots of difference price points. Some even have mounts that can be changed if you swap systems, which is a very real benefit for future-proofing your purchase. The benefits of cinema primes are that they usually have fast, large T-stops rather than the f-stop apertures of stills photo lenses. An f-stop is a theoretical number calculated from focal length and the size of the aperture opening, where as a T-stop is an actual measure of light transmission. So one lens set at f/2.8 might not let the same amount of light through as another that’s also rated at f/2.8 – but a T2.8 setting is consistent across brands and focal lengths. Cine primes tend to have a lot of aperture blades to give smooth bokeh, rather than the more jagged look of lesser lenses with fewer blades. And the aperture rings are often clickless, so you can change T-stop
smoothly rather than in set half- or third- stop settings, for the perfect exposure. If you plan to change aperture during a shot, then it’s the only way to avoid the obvious stepped changes in exposure. The majority of cine primes have fast maximum apertures to allow in a lot of light, and give a correspondingly shallow depth-of-field. This can give a lovely cinematic look, but means getting your scene in focus is crucial and more difficult. To help you control focus, cine lenses have geared rings that are married up to external accessories, such as a follow focus rig. Sets of lenses are typically the same size, so it’s easy and quick to change accessories like rigs, matte boxes and follow focus systems. Of course, this does take time, so using primes isn’t as quick as using zoom lenses. A huge benefit of a manual cine prime is the long throw of the focus ring, and the very precise, tactile control it gives to the filmmaker. Compared to lenses designed for DSLR photo use, which have a much shorter throw or are often fly-by-wire rather than having a direct mechanical connection, they are much
easier to accurately control either with your hand or via a follow focus rig. But for shooting 4K at wide apertures, realistically you need to use an external monitor with accurate focus peaking or other focus tools, to get everything sharp. That’s the price you pay for a cinematic look. A final benefit of cinema lenses is that they are designed to minimise or eliminate the phenomenon of focus breathing. This is when you change focus and get a change in angle of view – almost like you are zooming. It’s especially noticeable when racking focus from very near to very far subjects, or vice versa. Cinema lenses are designed to avoid this by using different internal focus systems, compared to those typically used on stills lenses. Cine primes do have some disadvantages, though. Many do not communicate with the camera, so there will be no automatic corrections for aberrations or vignetting. Of course, you need to invest a lot to have a complete set, and it takes time and resource to be carrying the whole kit and switching focal lengths all the time. And unlike a zoom, where you can set the precise focal length you want for the perfect framing, your prime might not be the exact length you want. They are also not made in the most extreme focal lengths, like fisheye-wide or super- telephoto. For those extremes, you will need DSLR glass. “Cine primes have a lot of aperture blades to give smooth bokeh”
IMAGES Mounting a prime cinema lens like a Xeen (top) or Sigma (left) opens up a world of amazing bokeh, shallow depth-of-field and ultimate quality
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SPRING 2020 PRO MOVIEMAKER
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