Which camera should I get? Will there be something better soon? I’m asked those two questions almost daily. I wish I had definitive answers, but the truth is on a sliding scale. The best camera as of this morning might be replaced by an even better one this afternoon.
We’re in the middle of a high-stakes arms race among movie camera makers. Ever more intriguing and feature-packed offerings are constantly appearing from companies like Sony, RED, Canon, Nikon, and Panavision. When is it going to stop? How much is enough? When will you find the last camera you’ll ever need to buy?
Figure 1: An ARRI 435 XTREME 35mm motion picture film camera.
In this article, I explore several attributes that contribute to the image quality of a camera. I try to identify how much quality is enough to satisfy even the most discriminating eye with zero compromises. In positing the Ultimate Camera, I’m thinking of a camera that might not even be on the horizon yet and may never be. These parameters include the medium (film vs. digital); resolution (standard definition, high-definition, 2K, 4K and up); sensor size; frame rate (24p, 30p, 60p and up); codec (compressed vs. raw); form factor (compact vs. shoulder camera); 3D vs. 2D; sound; and exhibition format (again film vs. digital). As I go through each attribute, I describe the current state of the art and where I think it needs to go to be the ultimate camera.
Medium: Film versus Digital
35mm motion picture film was popularized at the end of the 19th century. Despite the advent of color and larger gauges such as 65mm (and up to IMAX), it has remained relatively unchanged for decades. Faster and sharper stocks have in some ways defined the visual look of different movie eras, but essentially you could load a 2009 Kodak film stock into a Panavision Panaflex camera from 1977 and start filming. Try plugging a 2009 Sony HDV tape into a 1977 Sony video camera, however, and you’re out of luck.
Digital video came into its own during the mid-1990s and at this point threatens to eclipse or at the very least equal celluloid. In the past few years, major theatrical releases have been shot digitally, using cameras like the Panavision Genesis (Superbad, 21), Sony CineAlta series (Sin City), Cloverfield) and the RED ONE (Knowing, and District 9. But it’s led to an ongoing debate: Does film look better than digital? Every year, more experts slide from the film column over to the digital column. That makes sense, because digital cameras continue to evolve while film remains relatively still.
One area in which film holds an edge is exposure latitude. Film has up to 11 stops of range between the darkest and brightest shades it can render, while digital lags a few stops behind. This can be mitigated in still cameras with High Dynamic Range (HDR) photography but digital movie cameras don’t quite have this feature... yet.
Figure 2. A 1951 USAF resolution test target still used to measure resolution of imaging sensors.
I believe digital will ultimately completely replace film as a capture medium; it almost has completed that transition in the still camera world. When was the last time you took 35mm still film to be developed and to have prints made? Digital is cheaper, faster, and eventually will be capable of better image quality than film. Therefore, digital is the medium of our ultimate camera.
Resolution: SD, HD, 2K, 4K, and beyond
Resolution goes hand in hand with medium. Film used to beat digital unequivocally here because the resolving power of a 35mm negative greatly exceeded a standard definition PAL or NTSC TV signal. That started to change in the late ‘90s as high-definition took hold as a broadcast and high-end camera format. HD proliferated into the 21st century as prosumer high-definition cameras became more affordable. Such notable landmarks in HD include the HDV-based Sony FX1, Panasonic HVX200, and Sony EX1, which shoot 1920x1080 HD (or 1080p) resolution for under $10,000. But film’s resolution still beats 1080p high-definition.
You need to move up to at least 2K (2,000 horizontal lines of resolution) to approach film quality. That’s the resolution used during the color correction (also called a digital intermediate (DI)) of most theatrically released films today. The 35mm negative is digitally scanned at 2K for the DI and then ultimately re-recorded back to a new negative for exhibition (or projected digitally).
Keep in mind the concept of oversampling: The files used for the DI are recorded at 2K but that’s reduced down from the larger image area of a 35mm negative. So the apparent resolution of a 2K film scan is much greater than, say, a camera that photographs natively at 2K.
Figure 3. A 21 megapixel CMOS sensor from a Canon 5D Mark II.
That’s why cameras like the RED shooting at 4K native resolution are taken seriously as competitors to film. Some experts argue that there’s a big difference between shooting resolution and apparent resolution, but I’d say most people watching movies like Knowing and District 9 don't notice. So once you hit 4K you’re pretty close to the apparent resolution of film-originated footage.
And with cameras are on the horizon shooting 5K (like RED’s EPIC) and more, you can envision a day when film’s resolution advantage will ultimately be surpassed. As far as the ultimate camera, I’d say once we hit 6K we’d have as much resolution as the eye can process.
The sensor size of digital still cameras is expressed in megapixels, one million pixels. For example, a camera with an array of 2048×1536 imaging elements has 3.1 megapixels (2048 times 1536 equals 3,145,728).
The Sony EX1 1080p prosumer camera has a 2.2 megapixel sensor while the professional Sony Cinealta F-35 and RED ONE cameras have 12 megapixel sensors. In the F-35’s case, that’s down-sampled in the camera to a 1080p frame, while the RED ONE produces a 4K frame. So you can see why the argument rages over sensor size versus apparent resolution.
Figure 4. The Panasonic DVX100 was the first 24p prosumer camera.
The 5D Mark II has a 21 megapixel sensor, perfect for capturing high resolution stills. Use that for video, and you get very sharp footage with extremely shallow depth of field. On paper, both of these Canons look great and indeed have proven very popular with professionals and high-end enthusiasts but I have a couple of concerns.
The ergonomics of still and motion picture shooting don’t seem to mix; you’ll find even the lowest end video camera to be easier to handle than a DSLR for shooting video. These cameras are also limited by frame rates. In the case of the 5D Mark II, there’s no 24p mode, which most digital moviemakers would consider essential to capturing that classic film look. The 7D has 24p but uses a slightly smaller sensor (18 megapixels), which translates into a deeper and less-cinematic depth of field. That said, for the $1,500 to $2,600 these cameras cost, they merit a serious look.
In terms of the ultimate camera, I think somewhere in the neighborhood of 20 to 25 megapixels would about do it to meet or exceed film quality.
Frame rates: 24p, 60p, 120p
I just mentioned 24p; that is 24 progressive frames captured per second, the same as film. Most digital motion picture cameras today shoot 24p as their main format because the results look much more like film than any other frame rate. That’s just hard-wired into our brains after 100 years of watching movies. But is 24 the magic number for the ultimate camera?
IMAX HD runs at 48 frames per second, producing smoother motion and a more “lifelike” image. There are also the 120Hz televisions, which artificially speed up the frame rates of discs and broadcasts to 120 frames per second, like the Sony BRAVIA V-Series. This smoothes out and averages motion, creating a supposedly even more lifelike image. Personally I think the effect of these TVs is a bit fake and would look more believable if the original material were captured at 120 frames per second and then projected natively.
So does the ultimate camera need 120 frames per second? Maybe. But I’d guess 60 frames per second would probably do the trick. Try a little test for yourself by very slowly waving your hand close to your eyes. Now gradually speed up until your hands start to blur. You’ve just exceeded your brain’s built-in ”frame rate.” So obviously, there is a limit to what the human eye can process. I think it’s somewhere between 60 and 120 frames per second. And since we’re accustomed to watching at 24 frames, anywhere in-between would be acceptable to our eyes as well.