Film as a medium has inherent limitations, such as the difficulty of viewing footage whilst recording. It suffers other problems, caused by poor film development/processing, or poor monitoring systems. Given that there is increasing use of computer-generated or computer-altered imagery in movies, and that editing picture sequences is often done digitally, some directors have shot their movies using the HD format via high-end digital video cameras. Whilst the quality of HD video is very high compared to SD video, and offers improved signal/noise ratios against comparable sensitivity film, film remains able to resolve more image detail than current HD video formats. In addition some film has a wider dynamic range (ability to resolve extremes of dark and light areas in a scene) than even the best HD cameras. Thus the most persuasive arguments for the use of HD are currently cost savings on film stock, the ease of transfer to editing systems and for special effects. Notable directors who have used HD to a large degree thus far are: George Lucas, Michael Mann, Steven Soderbergh, James Cameron and Robert Rodriguez.
Digital Cinematography with the enhancement of digital capture techniques and the fact most cinemas now at least have one digital projector. The problem is that there are vast arrays of digital cameras out there, as well as a vast range of digital formats, as already discussed and not many come close to capturing the same quality image that you can on film. Digital cameras are not film but they have their own distinct look which modern film makers are utilising to give us a new style in cinema. HD and digital cameras are widely adopted as they are smaller and more mobile, plus ultimately the imagery is almost instantly available and can be worked easier in post. The RED camera has certainly made its way into the hearts of DOPs and delivering a superb quality picture.
Shooting a production destined for film or cinematic release is not the same as shooting for TV, although the boundaries are shrinking as the methodology and practices diverge. The differing array and myriad of formats/cameras have changed how the cinematographer captures their vision, however this brings even wider choices than ever before and a greater level of knowledge is needed to make sure the production runs smoothly.
The issues faced by a production using most HD cameras is their WYSIWYG (What You See Is What You Get) approach to the image. Video cameras have been designed mainly for broadcast and therefore can be classed as ‘instant imagery’ or what are basically ready for immediate transmission. Conversely film images since their inception, have to follow a path of post production to be viewable.
In essence to make HD cameras more filmic, one has to capture the image in a different way, emulating the low contrast of film and closely matching the higher dynamic range of film. Camera manufacturers have added 'film' profiles to their settings, to give a more filmic image, emulating a Log output image. However you must remember the assist monitor you are looking at on set will also appear to have a low contrast (of course you could always apply a reverse LUT), this technique will allow greater flexibility when colour grading in post.
Both Panasonic and Sony have introduced modes or settings of their own, capable of mimicking the above approach to image capture. Thomson introduced their Viper camera with a Log based FilmStream mode, however this methodology has a green tinge to the image and can be off putting to many Cinematographers.
Depth of Field
One issue for many users of these cameras is their depth of field; HD cameras have a deeper depth of field than 35mm film (akin to 16mm film). Ultimately many die hard film people still feel the digital images are too 'video-esk' when compared to film. Many new dedicated cameras are now emerging to combat the pitfalls of earlier re-purposed HD video cameras for use in the film world. High latitude, high dynamic range, low contrast capture has become comparatively commonplace, and some cameras are now using full 35mm aperture sensors, answering the final question, to enable true Digital Cinematography.
Resolutions have also increased, with new data cameras allowing the capture of 2K and even 4K. The Red One and Dalsa's Origin are examples of 35mm sensor based data cameras, and Silicon Imaging's SI being a HD sized sensor camera, but with 2K capture capabilities. There is the Arri D20 and Panavision's Genesis, which output an HD image signal (and resolution), but have 35mm sized sensors.
For capturing more than the standard 24fps you can use the Panasonic's VariCam, although this is inherently 1280x720 and opens up a difficult post production route if you are not familiar with the way in which the data is flagged and transferred to data or tape.
Cameras that record only to external tape decks, specifically Sony's HDcam SR format, can record 4:4:4 RGB with minimal compression, the limitation is the format’s HD resolution of 1920x1080 but compared to a film frame you can see is getting pretty close. Data cameras, as would be expected, record to data recorders either with or without compression, ultimately the user’s decision depending on shooting techniques and the data format and recorder in use.
Ultimately as I have mentioned in the Film module, the project at hand should dictate the way in which something is shot. Always consider new technology to capture images but in my humble opinion, a camera should not be used simply because it is new, or that you will be the first to use it within the industry. Sometimes it is easier, and certainly cheaper to learn from someone else’s mistakes, than to adopt or build from scratch an entirely new workflow just because you want to be a pioneer.