Digital intermediate (DI) is the new buzzword floating around film-based post houses - but what does it mean for the TV industry? David Wood investigates while Kevin Hilton looks at the new skills the process will require of Soho's online editors and colourists.
Digital intermediate (DI) is the new buzzword floating around film-based post houses - but what does it mean for the TV industry? David Wood investigates while Kevin Hilton looks at the new skills the process will require of Soho's online editors and colourists.

New technology has always brought change to those who operate the previous generation of equipment and, in the world of film transfer and colour correction, digital intermediate (DI) is currently changing the landscape.

Telecine is the conversion of film-based images to videotape. TV programmes shot on film need to be transferred to video to allow the pictures to be edited and then broadcast.

For this, they require cumbersome, expensive telecine (TK) machines (such as the Thomson's Spirit or Cintel's C-reality) which are usually kept in dedicated, darkened, airconditioned rooms in a facilities house or a film laboratory.

Currently, when the telecine machine scans and converts the film it is also graded - the process of -giving the image its look - which has always involved a highly skilled -telecine colourist.

The way a colourist uses colours in conjunction with the narrative of a film or TV drama can significantly influence the entire mood of a piece. Rich, warm colours may convey happiness, optimism and hope just as desaturated, colder colours can be used to achieve the opposite.

But a new workflow is emerging. With the DI process, film scanning and grading are separated so that the film is scanned to hard disk and later the grader works on the digital images which have been stored instead of directly from film.

The separation of the grading from the scanning, and the ability to create a finished film negative from a digital image, mean that all the standard video colour correction tools are now available for feature films and a director, producer or DoP can now gauge results immediately rather than waiting for prints to come back through the lab. DI systems also allow immediate access to online editing, special effects and compositing. In theory, this means that the whole process can now be carried out by an online editor rather than a dedicated colourist - although many in the post-production industry still believe that the role of the colourist will not be diminished by the emergence of new technology.

"The colourist is the last bastion job," says Phil Green, creative director and grader at Dragon Digital, a new DI facility in south Wales. "Colourists are sought after for their skills and command good rates. Things won't change from that point of view - what will change is the technology used."

But it's hard to deny that a new breed of operator is emerging from this change in technology - a hybrid editor who performs conform checking, some visual effects and a colour match. One such is the Moving Picture Company's Thomas Urbye, who insists that his colour-matching work does not yet threaten the -facility's established colourists.

However, Urbye admits that he's continually building his colouring experience and, as DI spreads, future colourists will become further removed from the traditional telecine process. However, this doesn't mean facilities are turning their backs entirely on old school colourists who come with a dedicated skills set.

When Wardour Street-based facility Lip Sync Post moved into DI without having had a traditional -telecine department, it spent time looking for experienced colourists. "We didn't want to automatically train up a senior editor," says Kevin Phelan, head of post-production.

The VTR Group also has a purpose-built DI department for feature film work but maintains a conventional telecine for pop promos and commercials. Colourist Duncan Russell has already made the move from telecine over to DI, which he feels allows him to be involved early on in other stages of post. "I can consult on some of the special effects and make them match," he explains.

The need for some retraining is not underestimated because, as Jet Omoshebi, a colourist at Pepper Post, observes, grading tools on DI -systems tend to be based more on editing technology. "There's an -element of retraining involved," she admits, "but the editors have a similar problem. It's not just about having 'the eye'; colour correction is a real-time, interactive function."

Because of this factor, online editors taking over colour work is not perceived as a serious threat to TK staff. "Grading is a specialised operation," says Steve Shaw, a colourist who advises DI facilities through his consultancy, Digital Praxis. "There's more chance of colourists picking up additional skills such as onlining."

This change in technology certainly hasn't precluded old style colourists from running the new systems. Vince Narduzzo, head of telecine at St Anne's Post, sees no great difference between DI grading and "a normal TV grade" if both are done on a monitor. The difference, he says, is grading on a screen. "That's a bit of a learning curve," he says. "Film graders will also need some retraining as the days of grading in the lab are numbered. In post suites DI is being done by people like me because I understand both Da Vinci [a telecine tool] and Baselight [a DI tool]."

Shaw believes that telecines will decrease in functionality, so getting them out of the colour suite and using them purely as a transfer tool to DI is the way ahead. Arthur Johnsen, film imaging and post-production account manager for Grass Valley, agrees. "In 10 years telecine will still be around but it will be more of a background device," he predicts.

Even today sales of telecine machines remain healthy. Cintel continues to sell SD machines and over the past 18 months Grass Valley has supplied Spirit 2K/4K datacines to Framestore CFC, Midnight Transfer, Technicolor, The Mill and Glassworks.

While the machines may be around for at least another 10 years, there are still concerns that the artistic value of colouring is being lost in the technological and financial arguments.

But as much as DI could be seen as a threat to the old ways, the facilities sector, as always, is adapting.

Goal! - a DI case study

Shot on 35mm, recent UK feature Goal! tells the tale of a talented Mexican footballer Santiago Munez (Kino Becker) who grows up in LA and sees little hope of realising his dreams until he is headhunted to join Newcastle United. Golden beaches and year-long summers are then replaced with muddy pitches, cold winds and crunching blows from team mates. To create dramatically contrasting looks in the film between Mexico, Los Angeles and Newcastle the production team went to Framestore CFC's Digital Lab where senior colourist Adam Glasman worked on a digital intermediate (DI) that would offer a range of looks for the different locations. The original camera negative was scanned, conformed and graded using FilmLight's NorthLight Scanner and BaseLight grading system. Senior colourist Glasman then worked with DoP Michael Barrett and director Danny Cannon to create a strong look for the scenes set in LA and Mexico. "They're bathed in a warm and golden light. They'd used some tobacco grades but much of that golden look was added in post," says Glasman. Unsurprisingly, for the Newcastle scenes a much cooler look was created. After colour correction, the finished result was shot back onto film using an Arri laser recorder. The traditional lab route of finishing features allows only corrections of colour and brightness to be made. With a DI, the client can use a much more powerful digital toolset to make real-time changes to saturation, contrast and colour, as well as selectively altering specific details within the frame; while viewing everything on a 2K digital projector.

Our panel

Andrew Johnston, FilmLight sales

Andrew joined FilmLight as sales and marketing manager in July 2004, bringing experience in marketing at Discreet, Softimage, Kaydara and Unique ID. He's responsible for the sale of all FilmLight products such as the Northlight scanner, colour grading system Baselight and Truelight, which allows comparison of the digital image with a film original.

Shane Warden, Pepper Post joint MD

Shane Warden is joint managing director and senior DS artist at Pepper Post. He started his career as a Channel 4 engineer, before working for seven years at YTV as an online editor. Shane joined TVI as senior editor in 1995, before moving to West1 TV and Pepper. He has a reputation as a leading light in HD posting.

Mark Foligno, Molinare joint MD

Mark took over as MD of Molinare in July 2003 before negotiating an MBO from TV Corp along with joint MD Steve Milne. Since then Molinare has become heavily involved in HD and DI and is currently working on some major film and TV projects.

David Klafkowski, director of operations, the Farm Group

David is responsible for the technical specification of all the Farm Group's facilities - The Farm, Home, The Shed and Uncle. Home opened up in 2000 offering the UK's first full service HD facility.

Our panel of experts tell you everything you need to know about digital intermediate, from what processes it is replacing to the dangers that could catch out inexperienced users

What is DI?

Andy Johnston:

It means different things to different people and depends on how strict you want to be with the terminology. In film it's the process of transferring to digital for fixing and finishing things in post before going back to a film print. In TV people refer to it as transferring from tape to a digital format, but both definitions are about processes concerning the finish and look of the piece; changing colour balance or mending the fact that the lighting on the set wasn't effective or changing viewers' focus on what's on screen.

Shane Warden:

DI is a term used to describe feature film post-production carried out in the digital domain. Regardless of whether you're shooting on film or HD, the digital intermediate stage is what goes on between shooting and projection. If it's done digitally it's DI, if it's on film, it's not.

What are the traditional processes that it is set to replace?

David Klafkowski:

The telecine lab processes. The end game is a totally digital post-production and delivery system without going back to film. If you've shot on film you scan it once at 2K or 4K and from that scan you grade your DI. But I can't see a day in my lifetime when film will stop being used as an acquisition medium.

What tools are involved in the DI process and what pieces of kit are they starting to replace?

SW: You use the same scanners and telecines as normally and from that point onward you would grade on the normal systems - Da Vinci, Pogle, Lustre, Baselight, Discreet, DS Nitris, Quantel. But you've got to remember that if you are scanning at 4K you are going to need some serious processing horsepower.

What are the advantages of DI over these traditional methods in terms of cost, time and efficiency?

AJ: There's a chunk of efficiencies because by transferring to digital you can do things in a non-linear way, allowing immediate access to online editing, special effects and compositing, plus there's no lab time so you don't have to wait before you can see how digital manipulation of the film image will look.

Is it used in TV programmes?

AJ: DI-style workflows are certainly becoming more common as the market moves towards HD. The fact post houses are upgrading to HD is a good opportunity for them to look at what kit is out there that can cope with the extra processing power that HD entails. A DI-style workflow in TV means you can shoot on anything from DVCam to film to HD and in the final programme mix all that up. DI working and colour grading allows you not to have to worry too much about how different formats will look in the final product.

What do post supervisors need to know about DI?

AJ: How it changes the workflow. They might need to take money from different funding pots - the traditional dailies budget, finishing budget or the deliverables budget - to finance the DI process.

Does the HD format have any bearing on DI?

Mark Foligno:

HD affects DI a lot. We use HDCam-SR as an interchange format and deliver onto HDCam or HDD5 - it's enabled us to use HD as a DI format. But it's crucial to understand that HDD5 is heavily compressed - after six to seven generations you start to see artefacts. HDcam is even more compressed. You have to appreciate the limitations of the technology you are getting into.

Do post-production facilities that are not already offering colouring services need to think about adding them?

AJ: With DI workflows it's possible to get into colour grading without having a telecine - that's new. Particularly with the BBC doing more post work in-house - post houses need to adapt and develop, offering the kind of services that the BBC isn't. Colour grading is going to make you more money than just about any other thing you can do in post. If you can do the colour grading the chances are you can hold onto digital effects work and dubbing' It becomes a rain-maker for the facility.

SW: It's got the potential to be lucrative - certainly for the manufacturers. The problem is if you're tempted to do film work the stakes are so much higher than TV. If you're not used to working with feature film clients, be warned: it's a completely different world and you can't just 'Elastoplast' over the cracks. Everything is on a much bigger scale - particularly with issues such as storage - and the -potential risks are enormous with missed deadlines. A $20m lawsuit from a US studio is no joke.

What are the dangers of jumping into DI if you're new to it?

MF: It's a steep learning curve. These are big files you are throwing around - 12Mb per frame of 2K and 50Mb for a 4K frame is a lot of data so your infrastructure will soon be full with one or two projects. You have to look at what you are delivering, how your clients expect it to work and go forward on that basis - working back from the end point to the start.

What do producers need to know?

MF: Decisions about scanning have a huge impact. Do you do it at 2K or HD? What aspect ratio are you ending up on? And what deliverables will the broadcaster need? All these questions have to be asked up front before going into DI. If you make mistakes at the scanning stage the consequences are very difficult to recover from.

DK: It's easy to forget that DI is about people, not hardware. There are lots of boxes on the market that can do it but few people have the colour grading expertise of [The Farm's] Aidan Farrell, say. What really matters is the content.