With a vast array of cameras to choose from, posting work in 4k has recently become fashionable - but it can also be very costly and impractical.

As high-definition tapeless acquisition starts to be used across genres from news to factual entertainment, digital capture up to four times the resolution of HD is beginning to reach the top end of the broadcast chain.

The rise of digital cinematography and the demise of negative film has long been anticipated but cheaper technology appears to have brought that day closer.

A handful of producers are experimenting with 2k to 4k digital cameras for drama and short-form projects and they face a bewildering variety of cameras to choose from. These range from the Dalsa Origin, which claims to be the first camera capable of 4k capture, to the Arri D-20 (shooting BBC drama Little Dorrit). Others include Thomson's Viper Filmstream, Silicon Imaging's SI-2K (popular for stereo 3D recording), the Panavision Genesis and Vision Research's Phantom (for high resolution slow motion).

Many of these mimic 35mm film depth of field by using single 35mm-sized sensors as opposed to the 2/3-inch image sensors of video HD. Most also provide the option of recording to either a tape format or direct to disc as data.

The reason the broadcast community is buzzing about digital cinematography is Red, a Californian developer which has had the nerve to take on Japanese camera giants such as Sony at their own game.

At the beginning of the year it began shipping Red One, a£10,000 4k data camera aimed at replacing 35mm for feature film and drama, and in April announced not only a successor called Epic which captures at even higher resolutions but a portable version dubbed Scarlet which for just£1,500 records 3k onto two Compact Flash cards.To put that into perspective, professional broadcast standard HD cameras which capture the equivalent of 2k resolution cost around£40,000. Other digital cinematography cameras can cost double that.

“If Red delivers on its promise, these cameras have the potential to make a huge impact on independent production, which has struggled to afford the cost of entry into quality HD,” says Envy chief engineer Daniel Sassen.

Axis Films is one of a handful of UK suppliers of Red One. Managing director Paul Carter expects it to have “a dramatic effect in providing feature film quality images that are completely accessible to the corporate and entertainment markets.”

Unit managing director David Peto is among many Soho post-producers to have seen a sudden rise in Red shoots. “We're on our ninth Red project - mainly for commercials and music videos,” he reports. “Producers are basically trying to get 35mm production value on a budget.”

There's nothing wrong with that of course - except that working with the current crop of high-end data cameras can be a false economy. “The push from film into digital acquisition is being driven by financial rather than quality imperatives,” declares Ascent 142 chief technology officer Adrian Bull.

Pepper Post joint managing director Shane Warden agrees: “These cameras are aspirational and will always be the preferred option for a DoP who has been told that film is out of the question. However, the production is forced into dealing with a small number of suppliers which hold the monopoly on the technology, leaving the production looking for extra funds - usually at post's expense.”

“There's a steep learning curve for facilities and producers making the leap to these types of camera,” observes Blue Post production executive Sara Hill. “As soon as Red came into the country we got hold of one and did tests to be prepared for any jobs that come in. If you don't set the workflow up correctly it could prove very costly.”

Even cinematographers who are experienced at filming in video are wary of the fast pace of development.

“The problem with electronic equipment is that it relies on new software which is being beta tested in the market,” says DoP Gavin Finney, who used the Arri D-20 to shoot Terry Pratchett's Hogfather and The Colour of Magic. “That's fine for word processing but it's not okay when you're shooting on a big-budget drama. The kit needs to be reliable before it's used and currently that's not always the case.”

Red's critics claim that its proprietary codec complicates production, although details have now been released to third party manufacturers so this problem should ease. Those renting or buying the camera will need to factor in the cost of key accessories - the most critical of which is a lens which can triple the initial quote.

“The biggest mistake people make with Red is to treat it like a video camera,” argues Bull. “They don't realise that you need a proper camera team to operate it - including a DoP, focus puller and someone to look after the data.”

A Red spokesman says: “Certainly, the Red One is not a video camera. Its operation, function and workflow is more akin to a motion picture film camera. It uses the same lenses as a 35mm film camera and its post is very similar to film, in terms of grading and final.”

While producers are continually advised by post houses to shoot at the maximum resolution possible in order to preserve detail, shooting at resolutions above HD can actually deliver too much information.

“There is limited benefit to shooting at 2k or 4k when the output is standard definition,” says Prime Focus London creative director Derek Clarke. “Even if the output is HD, the 4k image contains so much detail that you need to take some information out of the image before it can be compressed into HD otherwise the codec simply can't manage it and you end up with artefacts [pixelation].”

Warden agrees: “Posting in 4k for HD is like driving to work in a Formula 1 car - we'd all love to do it as it's flashy but it's very costly and not practical.”

The debate over whether digital imaging is superior to film is hotly contested. Certain digital cameras can have the edge over film in terms of their ability to capture detail in low light but many cinematographers argue that 35mm and even 16mm perform far better in daylight or for capturing explosions.

“If the output is HD then the advantage of shooting at higher resolutions comes from the greater colour depth, allowing the picture to be pushed a little further in the grade,” explains Clarke. “4k is also good for VFX-intensive projects because in 4k you can extract detail for tracking or reframing, resolve composites or key in backgrounds and still finish with a great image.”

“Film remains the benchmark,” states Milan Krsljanin, business development manager at Arri Media, which continues to do sterling business renting its 35mm and 16mm cameras. “We believe that our digital cameras [D-20 and D-21] are the best on the market but they are still not as good as film. No single digital camera can rival film's performance in terms of exposure latitude [the extent to which a light-sensitive material can be over or underexposed].”

Sooner or later digital technology will exceed the colour depth and resolution of film: “Why bother with developing, telecine, 2k scans when you can take the files straight out of the camera and start editing?,” asks Jon Wright, workflow consultant for facility 4K London.

Other arguments for shooting 4k will be familiar to those who pioneered HD. “There is a point in shooting 4k, producing a 2k version now and having it stored as 4k data to future-proof your rushes,” explains Bull.

4k will present a genuine challenge for facilities simply because the infrastructure required to manage it lags way behind. Currently there are very few 4k projectors and monitors around, let alone real-time 4k colour graders.

“The sheer size of the images complicates the process,” declares Avid marketing manager for post-production facilities and services Vincent Maza. “Post houses will need to invest in larger, faster storage systems that can preserve their workflow.”

“Most productions will downsize straightaway on ingest to 2k or 1080p HD for their post pipeline,” explains Wright. “The extra resolution makes a big difference at the camera stage, but can become an unnecessary complication after that.”

Facilities don't seem fazed by the introduction of new digital camera formats, arguing that a data-only workflow is simpler to manage than a “film to data to tape” one. However, Axis Films' Carter warns: “Our experience is that Soho houses are anything but geared up to handle data. They can't deal with high volumes of data since everything has to be converted into their existing tape-based set-up. They may claim to operate a data-centric facility but not all claims are verifiable.”

BBC1 drama pioneers the Red One
A new BBC1 adaptation based on the Kurt Wallander Mysteries books is the first UK TV drama to use the Red One.

The 3 x 90-minute series starring Kenneth Branagh is a£6m co-production between Branagh's production company, Yellow Bird, and Left Bank Pictures through BBC Scotland.

Together with director Philip Martin, director of photography Anthony Dod Mantle made the decision to use the camera instead of 35mm for budgetary reasons. “The bottom line is the quality of the image,” says Dod Mantle. “Given that I'm working against the clock with a small crew I can get away with less on set and achieve more with further manipulation of the image in post.

“I can get enough quality with my minimal lighting but magnify it significantly because there is much more definition, resolution and luminance.”

The drama is being graded at Swedish facility Chimney Pot and finished at The Farm.

“The problem with handling such a huge amount of data for broadcast output is at what point do we scale the files to HD?” asks The Farm technical director David Klafkowski. “You don't want to risk losing important image information by downscaling but at some point you have to, so you need to store the original 4k data in case you need to go back to it.”

Processing data ultimately takes as much time and cost as telecineing rushes. The problem is simply removed from the lab and into the post house. Consequently facilities must set up data management and answer questions like how many copies do we keep? Where are those copies? And which is deemed the master?

The role of a digital imaging technician
Most productions recording data require someone to manage that data on set. On feature films, it is becoming increasingly common to hire a digital imaging technician (DIT) and broadcast is gradually following suit as 4k capture becomes prevalent. The DIT is an addition to existing crew such as the video playback assistant. Consequently production costs rise.

Crucial part of production
“A DIT is crucial to production and will have a high level of expertise,” explains Axis Films managing director Paul Carter. “They have sole responsibility for the safe storage and archiving of data.”

The DIT takes care of metadata for use in post-production, spots and corrects any issues with corrupt files, and helps set up the camera and monitors according to how the DoP wants the project to look.

“Digital imaging is in a bit of a ‘Wild West' state,” says Carter. “The DIT's role varies from project to project. On some projects they may take more of a hand in colour management. There are no hard and fast rules.”

DITs bridge the gap
According to Gavin Finney, a former President of the British Society of Cinematographers: “DITs should act as a bridge between a second AC and a video assistant. It's certainly useful to have an engineer to monitor the electronics and check you've saved what you think you've saved, not least because with each new digital camera format the amount a camera crew has to learn goes up exponentially.

“My concern though is who is training them - since currently anyone can walk up and claim to be a DIT.”