The development of broadcast cameras has diverged from the expected roadmap of product evolution, led by digital cinematography and aided by the ingenuity of those who have adapted the DSLR. The question remains, however: What has driven this development?
The cinematography guys like to shoot with their favored sets of prime lenses and want sensors of a similar size to the 35mm gate to achieve a small depth of focus. Cinematographers have always been innovators: Many components have been built in a workshop, not a silicon foundry.
Electronic cameras are direct descendents of the old three-tube cameras, with a beam splitter and three color channels. The development of consumer digital still cameras called for a lower-cost solution, and the single sensor with a Bayer color filter array provided the answer.
Digital cinematography also adopted the single-sensor route. The long back focus needed for the three-chip camera format required lenses designed to suit, and that would have excluded traditional cine lenses. The size of the sensor in three-chip cameras is closer to the 16mm gate, so it could not replicate the depth of focus of 35mm film.
When Nikon added the capability to record video to the DSLR, it opened the door to a whole new way to shoot video. Canon and others soon followed, and video capture is now a standard feature on many still cameras.
The DSLR has definitely broken the mold of the three-chip cameras, where price decided the sensor size from 1/4in up to 2/3in. DSLR sensor sizes are more like 35mm film. The DSLR has also provided the opportunity for the more price-conscious shooter to use fast, fixed focal length lenses, rather than integral zooms. There is no free lunch, however; the audio facilities are rudimentary. The image processing and codec performance is optimized for low power consumption, not ultimate quality. The viewfinder must be augmented, and follow focus has to be bolted on. The resultant rig, adorned with cable ties, is a triumph of ingenuity over elegant design.
The three-chip camera has by no means been rendered obsolete by these developments. For news, studio productions and sports, it offers great image quality, professional performance and ergonomics developed through decades of use, and the beam-splitter allows for accurate colorimetry. The three-chip camera remains the camera of choice for television, but when more of a film look is called for, the large-area single chip is a better choice.
Without the camera, there is no motion imaging, and cameramen have never had so many options. From 4K to HD, single- or three-chip, there are cameras to meet any requirement. At the lower end, cost and battery life impose limitations on the picture quality that can be achieved. At the high end, basic physics are the only limits to image quality. We have arrived at this stage through a grass-roots revolution of users building what they couldn't buy. But now that camera manufacturers can see what users want, they have built properly engineered cameras to meet those requirements. They have proper viewfinders, XLR audio connectors and long record times — all the features a professional wants.
Choosing the right cameras and lenses is a personal affair because they affect the final look of a production more than anything, apart from the lighting. It is this personal nature that has led camera operators and directors of photography to drive innovation. There is now a wider selection of imaging devices than ever, from ENG to high-speed capture for special effects, so much so that it is now possible to do pretty much anything with electronic sensors that used to be shot on film.
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