Director of photography Sean Bobbitt BSC explains how he shot a series of short films based on famous works of art using the Arri D-21 digital cinema camera in raw capture mode.

Article first published: May 2009

There’s a director I’ve worked with who’s come up with the concept of recreating specific works of art using modern visual mediums, as a way of introducing the art to a modern audience. He’s been commissioned by a museum in Fort Worth, Texas to create five small films based on works of art owned by the museum, and the first was The Butcher Shop, a painting by Italian renaissance artist Annibale Carracci. The idea was to recreate the painting itself and the moments leading up to it. We were looking for the highest quality medium we could use to capture the images, some of which were going to be digitally worked with afterwards to create a photographic representation of the painting itself. I knew that Arri was getting very close to testing the Raw Data Capture on the D-20, but in fact the camera we used was an early prototype of the D-21. Arri’s desire was for a project to test the Raw Data Capture workflow, and ours was to recreate imagery of an exceptional nature, and the two seemed to fit together quite nicely.

Physically, the D-21 is exactly the same as the D-20, but it’s had extensive changes in its software and circuitry, and significantly improved signal-to-noise ratio. Because it’s designed by Arri, it fits with all the other Arri accessories. So if you had a film camera, you could just take the film camera out and slot in the D-21. It’s also simple to use because it’s based of film camera technology. The menus are very simple, and they only do what you need them to do, there’s not a lot of gubbins to mess around with.

The greatest single feature from an operator’s point of view is that it has an optical look-through, so what you see is what you get. If you’re used to working on film, then you know this is fantastic, and there is no other digital camera that has an optical look-through. You get no lag at all, of course, it’s not black and white, you know exactly what you see is what you get, and that is a huge benefit.

Along with all the film accessories, you can use standard 35mm lenses, so your optical quality is absolutely maximized, and again, this a huge leap forward from earlier digital cameras where we were having to use specially made digital zoom lenses, and the quality of those wasn’t anywhere near the same as prime lenses. So you’re maximizing your optical quality as well as all your picture information, and for a DP, more often than not it’s the lens that really matters.

Part of the beauty of the D-21 is its flexibility. You can shoot it in so many different ways depending on what the ultimate application is going to be, in terms of transmission or projection. You can shoot in linear, 4:4:4, 4:2:2, onto HDCAM, onto anything you want; or you can shoot it log C, which is putting you in a cinema color space. Again, most people go 4:4:4 onto an HDCAM SR recorder, or you can shoot it log F, which is more of a television color space, again onto the SR recorder, and again you can go 4:2:2 or 4:4:4, depending on how you’re going to post-produce. Or you can shoot it raw data capture, and at this point it’s only the S2 recorder that has the capacity to take in that much information and store it. The flash mags simply aren’t fast enough or large enough the take that level of information.

In raw data capture, the dynamic range is quite astounding. You are getting close to 35mm, although 35mm still has the edge, particularly in the shadows. But compared to other digital cameras, particularly the earlier HD cameras, it’s truly astounding. On The Butcher Shop, there are white shirts that are quite brightly lit, but I had no doubt that all of the information and detail would be retained in those highlight. Black is always a tricky thing. Initially, the D-20 was renowned for having noisy blacks, but the D-21 doesn’t have noisy blacks.

For me, sensitivity isn’t the most important thing. It is the clarity and quantity of the picture information that matters. I don’t need a high-speed camera; I’m working in drama, not documentaries. I can light it up to what the camera requires. So we rate the camera at 200ASA ostensibly, but it depends on what you’re shooting in. If you’re shooting linear, then you can also rate it 320 or 500; you can adjust the sensitivity to your requirements. Of course, you start to introduce noise as you increase the sensitivity of the chip. If you’re shooting in log space, or in raw data capture, then the chip just catches everything. You don’t rate it; it is what it is.

What you end up with in raw data capture is, of course, just data. So you have no image at all; you have to create a 3D look-up table (LUT) to even see what it is, and even then that only gives you a proxy of the image. So in some ways it is very much like working on film; you are acquiring the information, which you record onto a recording medium, you then take that information and process it. In our case, we processed it through the Arri Image Booster software to create 10-bit DPX files, from which we could then conform and grade the material. DPX is becoming the standard for high end post-production; it’s completely uncompressed, so each frame is an independent file containing all the picture information that has come straight off the chip. So you’re maximizing the quality of the optics, and the quality of the chip, without compressing it in any way or denigrating the quality of the image.

To get a sense of the image, we created our LUT and ran the information out of our S2 recorder and into a Cine-tal monitor. The Cine-tal has a built-in computer you can download LUTs into. We pre-created a LUT for the shoot so the director could see what was going on, although of course it’s only metadata – it’s only a possibility of what the image might look like once it’s been processed – but it gives you enough information for you to see that what you’re doing is what you want.

The workflow for the D-21 is dependent on what format you’re shooting, and every format has a different route. With raw capture, it’s a matter of acquiring all the data uncompressed onto the S2 recorder, which puts it into the DPX wrapper. You then take the drive, plug it into another machine and make copies. These become your archive and your master, which are stored on LTO4 tape. It’s just a data tape, but you are moving out of the virtual domain onto something solid, which is a major requirement if you’re shooting a feature film. If you want to get the film bonded you have to get it on to a tape format. That LTO4 is then plugged into a RAID array and the image is processed in Image Booster, and debayered, at which point we put it onto Firewire drives. Post-production was taking place in New York, so the director was able to take the Firewire drive with the 10-bit DPX files on it to New York and simply plug it into their system.

It is incredibly flexible once you get it into the 10-bit DPX file area. You can go anywhere with it and do anything to it, in fact they cut it there, they conformed it in New York, they sent a Firewire drive back to me and I took it to my favorite grading house. They were able to just plug it into their system, grade it, and lay it back onto a Firewire drive. That drive was taken to Munich where it was burnt out on an Arrilaser by Arri and transferred to 35mm film. So, once the material has been processed into DPX files, it’s very easy to work with.

Initially, I think that all of the digital formats were far inferior to film in terms of the quality of the imagery and the complexities of the workflow associated with it, but we’re seeing movement now with cameras like the D-21 and the Genesis into an area of image acquisition that is starting to comparable to film, and in terms of the quality of the images it is very exiting. You still though have the problem that connected by a cable to a separate recording system, and that is a huge step backwards in terms of technology. If you’re used to 16mm or 35mm film, where you have the freedom to move the camera wherever you like, it is actually really restrictive, and something I know manufacturers will be addressing in the near future. For me, that is the single major problem.

At this point in time, the D-21 is my camera of choice by far for drama acquisition.

Sean Bobbitt BSC Sean Bobbit BSC is a cinematographer whose work includes Sense and Sensibility (BBC), Mrs Radcliffe's Revolution, The Long Firm, Jeffrey Archer: The Truth and episodes of Spooks.