When people say that DSLR cameras provide a strong cinematic look, they are often referring to the nice shallow depth of field that those cameras give. The best way to get a nice shallow depth of field is by using a lens with a big aperture (lower than f/2.8). One of the most important advantages of DSLR cameras is the possibility of changing lenses. A lens may be permanently fixed to a camera, or it may be interchangeable with lenses of different focal lengths, apertures, and other properties. Big aperture comes from fast lenses, and if you're on a budget, primes are the way to go. Lens with big aperture are always costly and it is not affordable for everyone.
Fast zooms are more expensive : the more range you try to put in a zoom lens, the more compromises you must make, you lose quality in order to get range, or you spend a lot more money to keep the quality. Beginners often have only a kit with a DSLR body and a zoom lens. If you work on a short film or on a feature film, and if you ask me what lens you should buy with your DSLR camera, then my answer is in fact not to buy just one lens. You can also consider to rent a set of lenses. My answer would be different if you work on a documentary, because you could seek a wide-range zoom to duplicate what you could do and shoot very quickly.
Fast prime lenses are big and heavy if you have to take more than 3 of them at a time, but you need them to be able to focus on a person and leave the background, and also the foreground, blurry. Remember that you often need to do that to define a good composition of your shot. Fast lenses need less exposure time or can shoot in lower light, and I like to shoot at night. I like night life and night landscapes. So, I need fast lenses for those really dark scenes (indoors and outdoors). Most of my next short film will be shot at night.
I shoot with the Canon 5D mark II, and I carry all the time :
- The Canon EF 24-105mm f/4L IS USM, this is my travel/walk-around zoom lens and my short focal length lens, it has an image stabilizer which can be useful, but it is quickly limited in low light conditions
- Zeiss Planar T* 50mm f/1.4 ZE, this is the lens I use most of the time on my productions : long shots, medium shots, point of view shots, two shots, over the shoulder shots, american shots
- Zeiss Planar T* 85mm f/1.4 ZE : this is my best portrait lens, it shoots most of my best footage, sometimes for medium shots, and at least 90 per cent of my close-up
The Zeiss 50mm is my "normal" human eye lens. No lens sees what the eye can see, but the "normal" lens serves as a constant. On one side of this norm there are the "wide-angle" lenses, which have a greater depth of field, and on the other, there are the "long" lenses, which compress space.
DSLR lenses by Carl Zeiss are robust, offer a high aperture speed, and feature an especially harmonious rendering of the out-of-focus area. Zeiss lenses are my favorite in low light conditions, and I think that it is a reasonable alternative for getting started in this business.
During the NAB Show in Las Vegas, Carl Zeiss introduced an attractive bundled lens set offer for its SLR lenses. The set contains the following lenses with EF bayonet (ZE) : Distagon T* 2,8/21, Distagon T* 2/28, Distagon T* 2/35, Planar T* 1,4/50 and Planar T* 1,4/85... (FYI, in another price category, Carl Zeiss is also adding a new chapter to its Compact Prime CP.2 success story)
If you like Carl Zeiss products and if you have a budget, you should also consider to rent a Zeiss G.O lens set for your independent cinema production. A few months ago, the french cinematographer Crystel Fournier used the Zeiss G.O series with several Canon 7D to shoot the feature film Tomboy.
Finally, I would say that lenses can help to tell the story more powerfully. Keep in mind that the use of various lenses is one of the most important piece of the filmmaking puzzle because it enhances creativity.
