The Digital Intermediate - D.I.

Foreword

Digital Intermediate, often abbreviated or referred to as DI, is a process consisting of three separate processes of films 'scene to screen'.

  • Part 1 is considered to be the digitisation of the motion picture plates, known as scanning. Although as we have already discussed this could also be recorded in HD or another digital format, which does not require a lengthy scanning period.
  • Part 2 is understood to be the 'intermediate' section of the process. It is where manipulating the colour and other characteristics to change the look are creatively effected, it is usually the final creative adjustment to a movie before distribution in theatres.
  • Part 3 is the final stage where the manipulated, cleaned and compiled data is put back to film as the master negative from which the distribution prints are struck.

Although originally used to describe the process starting with film scanning and ending with film recording, the digital intermediate or DI is also used to describe colour grading and final mastering, even when a digital camera is used as the image source and/or when the final movie is not output to film. Some refer to it as the Digital Lab, which can also cause confusion.

This new process will influence on set production, to the delivery of content to consumers and everything in between! To see its full potential the Digital Intermediate process requires combining many skill sets from film and video infused with information technology (IT) professionals.

 

Ideally the process begins in pre-production with the production team finding a post house they are comfortable using and testing with them. The team should investigate different looks working to the boundaries of the material and also understand the workflow requirements within the facility, discussing their needs during production. As I’ve mentioned in previous sections, I personally think this is an absolute necessity so the DOP, Director of Photography, should be well aware of how to best exploit the advantages of the process, plus all of the production concerned is confident in the post house or creative(s) driving their project.

Additionally, the producer should understand how the DI would affect the budget and scheduling, because every post house will have its own unique workflow requirements and can recommended ways in which the production would get the best from their material and more importantly possible savings in production costs and budget.

The Digital Intermediate offers many enhancements over the traditional optical processes of old, so much so it is changing the film production route. Benefits for the production are multiple; the ability to see the project and review at any stage, greater colour control and ultimately the deliverables can be derived from one master timeline.

 

The Basics of the Digital Lab

For a DI facility to ultimately meet the needs of its client, there are a number of parameters that must be met by its intermediate process. Many bespoke operations have sprung up to cater for the client, all very successful, however there are many manufacturers and software options you can choose. You should at least become familiar with the major players and I shall interrogate a few within the ‘Manufacturers’ branch of this section. The point being, there are basic fundamentals which I feel need to be met to hold a DI project in its entirety.

  • You need enough disk space to hold every frame, segment/cut/scene, scanned or ingested; including handles (over scanned material), tails and VFX variants in the full pre decided quality, ultimately 2K, and 4K at best but could be HD.
  • Auto conform from the offline EDL or AAF
  • Playback the entire project, preferably in real time with temps, animation, previews and with full sound
  • Display the film in the true intended output colour space (3D LUT applied)
  • Perform basic functions for the completion of the project, basic editing, opticals, colour correction, titling etc.

As I have mentioned it is generally accepted a DI is carried out at 2K or 2048 x 1556 pixels, with 10 bit log sampling. A new ideology of DI is to utilise 16 bit data files, the push to this is gathering momentum. However playing these files in real time requires greater bandwidth and more processing power. 4K images are also now beginning to push the boundaries with real time playback and ease of workflow. However 2K is generally accepted as the standard, with good quality and enough headroom for colour manipulation.

The following headings conform, effects, dust busting and deliverables will hopefully illustrate the different areas of workflow within the Digital Lab, making the workflow understandable. Equipment is an addition to this section basically to introduce the idea of a “one stop shop.” A general ideal look at facilities using software and different hardware solutions, some are hybrids with a combination of both, but these types of machines are getting rarer as off the shelf hardware is becoming robust, stable and fast enough to do the work, thus many more facilities are able to offer part, if not all of the services required to offer their services as a DI Lab. I also added the manufacturers section here to highlight some of the companies dedicated to making DI work and manufacturer’s names that you may hear when approaching post production houses. Each section will give an idea whose products help for a smoother workflow, it is ultimately down to cost and personal preference of each facility to purchase and champion whichever manufacturers system. Forgive me for giving colour correction its own section but DI is greatly associated with grading and my background as a colourist makes me slightly more bias towards the subject.

 

Costing

Today the cost of a Digital Intermediate is anywhere from £60,000 to £120,000 GBP. This might still sound expensive to an independent producer but as more post production facilities have offered DI and technology has gotten cheaper, the costs have been driven down. What was once a niche market is being saturated by many post houses opening their doors and offering the service. However possibly one thing to bare in mind, some of these post houses are springing from other fields of expertise and you may be competing and having your time managed if a facility has many projects being ushered through its doors. Ultimately if they have sprung from a video background, one has to beg the question do they really know enough about film and its technicalities?

It is important though to look at the big picture when looking at costs. This process substantially reduces the cost to create HD, SD & DVD deliverables from the Digital Master timeline, thus saving repetitions in your pipeline. If the film was shot on 16mm the process also allows delivery to 35mm at no additional cost. Other cost saving can come from the ability to combine digital dailies and 3 perf 35mm in the camera, reducing by 25% the amount of film used per minute on the set.

The point is, the price of a typical DI is coming down and savvy producers will find ways to leverage this technique to reduce production costs while increasing the quality of their final deliverables, opening bigger markets for distribution and success.