Sky’s “Prisoner“: Inside a combined on-set DIT and overnight dailies workflow

Prisoner is a Sky Original action series that follows prison transport officer Amber Todd after an ambush leaves her handcuffed to a dangerous inmate. As the unlikely pair go on the run across Wales, the country’s dramatic landscapes become an integral part of the story. For freelance DIT Will Cook and Howard Colin, founder of Pixel & Process in Cardiff Bay, the project was an ideal fit. Not only was it filmed on their doorstep, its scale also called for the kind of closely connected workflow their collaboration is built around: combining on-set DIT, overnight lab, and dailies services under one roof.

In this interview, Will discusses the integrated approach behind this 20-week production, highlighting the collaboration between the on-set and lab teams and the key role Silverstack and Livegrade played throughout.

Will has gained experience in many areas of the camera department, working as a camera operator, camera assistant, loader, focus puller, and eventually as a DIT. Along the way, he met his future business partner, Howard Colin.

„Howard was the most technically minded clapper loader I’ve ever worked with; he used to always carry camera technicians’ handbooks around“, Will remembers. 

Despite Wales’ growing film and TV industry, there were no locally founded DIT companies at the time. Howard set out to change that by founding Pixel & Process and teaming up with Will. „In 2022, we then decided to open our digital lab in Cardiff Bay alongside our on-set work,“ Will adds. 

The move into lab services wasn’t just about expanding their business. It was driven by a challenge they had encountered again and again while working on set.

„The idea behind it came from years of watching the gap between what a DP intended on set and what actually arrived in editorial. Sometimes a communication problem, sometimes technical. We understood both sides well enough to think we could do something about it,“ Will explains. 

And they did. Most recently, Prisoner gave them the opportunity to put their approach into practice on one of their most ambitious productions to date. 

We could offer something genuinely different: a lab run by people with deep on-set experience, who understand the pipeline from both sides.

“Getting Prisoner a major Sky series, 20 weeks, overnight lab & full dailies service, was one of those moments we feel that gamble had paid off. It’s genuinely exciting when something like that lands, and you realise the risk was worth it. Prisoner is a strong example of what we do at full stretch. We could offer something genuinely different: a lab run by people with deep on-set experience, who understand the pipeline from both sides. For a production of this scale, that context matters.“ 

So, what does that look like in practice? 

Overall approach and workflow design 

“What made Prisoner work was a lab that understood what was happening on set—not just the files arriving on a drive, but the decisions behind them,“ Will explains. 

Some of those decisions were made long before cameras rolled, allowing the on-set and lab teams to align on the same creative and technical foundation.

„Before the shoot started, DP Aske Foss came into our Cardiff Bay facility to work through the colour pipeline with us over his test footage. We initially explored an ACES pipeline, but neither of us liked what it was doing with LogC4, the colour space transformation felt wrong for what he had in mind. We moved to an ARRI REVEAL pipeline instead, using the ALF-4 Rec.709 as our CMT and DRT, and decided to build the look through daily CDL adjustments rather than anything baked in upfront.“

For Will, those early conversations embodied exactly what they had set out to achieve. 

„Having Aske in our facility before the shoot was honestly one of my favorite experiences of the project. The moment we decided to abandon ACES and find our own direction inside ARRI REVEAL, that felt like exactly the kind of conversation we’d built the lab to have. A collaboration figuring out what a show should look like, before a single frame has been shot for real. The fact that we then carried that decision through 20 weeks of production cleanly, with everything arriving in the lab intact each night, is what makes this project mean something to us.“ 

That level of consistency depended highly on an infrastructure that allowed every team to focus on its own responsibilities while staying connected to the bigger picture. As Will explains: „The overall workflow was built around a clean division of responsibilities with on-set DIT and the overnight lab working from a shared pipeline.“

On-set setup & workflow

Will’s share of responsibilities covered all the core on-set DIT duties: 

„I was managing data, monitoring exposure, and running live color for our DP, building daily CDL grades with him throughout the shoot in Livegrade. Silverstack XT was my primary tool for everything data-related. I used it for offloads, checksum verifications, and metadata management. Every camera card was ingested, verified using xxHash checksums, and logged with complete shot metadata before moving on to the next stage of the pipeline.“

To support his on-set workflow, Will’s setup was built around a 14-inch MacBook Pro (M3) running Livegrade and Silverstack XT. Housed on an Innovative Apollo 40 cart, the setup also included:

• Two Sony PVM-A250 25-inch OLED monitors mounted on a Whaley Rail 
• A Tangent Ripple panel for hands-on color control via FSI BoxIO units
• Iris handsets for exposure control 
• A Blackmagic Smart Videohub 12×12 for signal routing, with camera feeds received via Teradek Bolt 6 wireless systems. The camera signal was also fed through to their video operator, Tom Frape, keeping the whole imaging chain consistent from camera through to video village 
• An EcoFlow DELTA portable power station providing battery backup for location work
• BNC cable drums for longer cable runs on location 

As Will describes it, the cart was “compact enough to move quickly, but fully specced for a two-camera daily operation with room to expand to four or five cameras on bigger days.“ 

That flexibility proved essential. The series was primarily shot on two ARRI ALEXA 35 cameras, recording  ARRIRAW HDE in 4.6K Open Gate at 25 fps, using Log C4 and ARRI Wide Gamut 4. However, the camera package was regularly expanded, adding further technical complexity. 

Keeping the colour pipeline and look coherent across all those formats was one of the central technical challenges.

„We also used a DJI Ronin 4D running as a C camera for specific sequences, shooting 6K ProRes RAW in D-Gamut/D-Log. We also had a DJI Inspire 3 drone shooting 8.1K CinemaDNG, as well as GoPros. Keeping the colour pipeline and look coherent across all those formats was one of the central technical challenges“, Will says. 

Livegrade played a central role in making that possible.

„Managing all cameras through a single Livegrade project was essential. Everything was visible and controllable from one place, with each camera’s treatment tracked separately. On days when we expanded to four or five cameras across multiple units, that single-software approach was what kept things coherent.“ 

Beyond keeping the technical side under control, Livegrade served as a creative collaboration tool. It gave Will and DP Aske Foss a shared space to refine the look throughout the shoot.

„Aske loved the familiarity of the ARRI Rec. 709 viewing environment, and the CDL approach gave him the freedom to discover the look as we shot. Each day we’d work on the grades together, responding to the light, the locations, and the tone of the scenes.“ 

To support that creative process, Will configured Livegrade so the DP could interact with and refine the look in a familiar, intuitive way. Using printer lights was central to that workflow, and mapping them to Stream Deck actions made their collaboration even more efficient, as he explains:

„The printer lights in combination with the Stream Deck were excellent for quick adjustments when managing multiple cameras simultaneously. And there’s something else to them, too: Printer Lights are a language DPs already speak. A lot of DPs can see and understand exactly what I’m doing as I make an adjustment, which can help keep the initial direction natural and immediate during a take. No translation needed.“ 

As the production stretched over 20 weeks, maintaining visual continuity became just as important as creating the look in the first place. Livegrade’s scene-based shot library provided quick visual references, helping preserve consistency throughout production and across both DPs.

Livegrade’s ability to save grades tagged to specific scenes and then search, compare, and apply them later meant we could track the look precisely across a 20-week shoot.

„Livegrade’s ability to save grades tagged to specific scenes and then search, compare, and apply them later meant we could track the look precisely across a 20-week shoot. Coming back to a location weeks later, I could pull up those grades, see where we’d been, and make sure we were consistent. That’s how you maintain look continuity across a long series, and how you hand that continuity to a second DP mid-production with confidence. That kind of institutional memory built into the software is something you can’t replicate manually.“

For Will, using tools that were built to work together was key to maintaining consistency across the production and streamlining his to-do list. Hence, he stayed in the Pomfort Ecosystem for both look and data management. 

„What made the workflow genuinely efficient was how the tools worked together. Once a card was offloading in Silverstack, I’d import my PFLA from Livegrade, tweak and perfect the grade, review it with Aske, and fill in metadata—all simultaneously while the card was still offloading. Nothing waiting on anything else.“  

Even under intense production pressure, Will and his team proved that a well-designed workflow could scale without losing consistency.

„We had a large stunt shoot that expanded to four Alexa 35s plus many additional smaller cameras around the space. The location at Bute Tunnel is a major dual carriageway through the city and could only be closed overnight. Hence, we shifted to night shooting for that stint. We brought in an additional data manager to help with the volume, because on wrap, we had to be out fast. Four carriageways of the road needed to reopen for the morning rush hour. Coffee was very much required! What made the extra crew so manageable was everyone living inside the same Silverstack project. The same structure, same handover process, just more of everything.“

The handover process

As each shooting day wrapped, Will assembled everything the lab needed to continue the workflow overnight.

„On wrap, I’d finalise the shuttle drive. That meant having all media verified, metadata exported from Silverstack, CDLs exported from Livegrade, everything organised into the agreed folder structure with military date and shoot day number. “

The shuttle drive was delivered by runner to the facility in Cardiff, where the lab team could pick up exactly where the on-set team left off, using Silverstack Lab. Sharing the same Silverstack pipeline and exchanging information via PSLA files ensured that the complete project structure and metadata were carried over seamlessly. 

What made it work was the metadata chain. Silverstack was running both on set and in the lab.

„What made it work was the metadata chain. Silverstack was running both on set and in the lab. At the end of each day, I’d export a PSLA file. It gave Howard not just file lists but the full context, clip names, camera reports, scene and take information, and the color metadata tying everything to that day’s Livegrade CDLs. That single export took about five minutes, and Howard had everything he needed to begin work the moment the shuttle drive arrived. No phone call at midnight asking what a grade was supposed to look like. The metadata told the story.“ 

As a result, communication became remarkably straightforward.

„Honestly, we didn’t talk much—and that’s the point. The Silverstack reports distributed at wrap told the lab everything they needed to know before the drive even arrived. Howard could see exactly what was coming, what it looked like, and what colour treatment it was carrying. When the software is doing its job properly, the conversation takes care of itself.“

Overnight lab and dailies workflow 

At the Lab, Howard and Lab Operator Natalie Ball processed everything through to Avid-ready dailies overnight. Their workflow included verified offloads to two production drives and LTO, quality control, Resolve transcodes with the CDL and ARRI REVEAL pipeline applied, sound sync, Avid bin creation, and finally uploading the complete delivery package to the editorial team in London.

As Will explains, handling sound sync at the lab was another way to create a more connected workflow and reduce friction between departments. 

„Sound sync is often the assistant editor’s job, time-consuming and detailed work that sits on their plate alongside everything else. By handling it in the lab overnight, it doesn’t slow us down, and we take that task off them entirely. They receive fully synced, organised media each morning ready to cut, without having spent their day doing it themselves.“ 

Because the workflow had been established before production began, the lab could continue working from the same creative and technical foundation as the set.

„Both set and lab were working from the same ARRI REVEAL spec, the same ALF4 LUTs, the same CDL export from Livegrade, and the same software. Howard’s lab monitors were also calibrated to Rec. 709 Gamma 2.4 to match the on-set standard. “

However, that alignment did not remove the complexity of managing footage from different camera systems. The challenges Will encountered on set continued into the lab, where the team had to find the right approach for each format within the overnight workflow:

„At the lab, the multi-format camera package was also the biggest technical challenge. The Alexa 35 pipeline was well-understood. The DJI Ronin 4D shooting ProRes RAW was a different matter; at the time, DaVinci Resolve didn’t handle ProRes RAW cleanly for our workflow. Howard solved it by creating mezzanine files, converting ProRes RAW to ProRes 4444 via colour space transformation before bringing it into Resolve. It added a step , but it was the right call. The drone CinemaDNG needed its own treatment, too. Managing all of that inside a coherent overnight pipeline with a hard morning deadline was genuinely demanding.“

As an additional layer of verification, the team also used Silverstack to create simple reference points between the set and the lab.

„Exporting stills from Silverstack each day with custom filenames meant we could quickly cross-reference looks between set and lab at any point, a simple, reliable sanity check that kept everyone confident the image was travelling correctly. If anything looked different, we could trace it to exactly where in the chain it had happened. In practice, the consistency of the pipeline meant that was rarely necessary.“

On a production processing 4–5TB overnight with a hard morning delivery deadline, any ambiguity in the handover would have cost time nobody had.

All of this contributed to an integrated process that not only maintained consistency but also helped the team stay on schedule. On a production of this scale, that was no small achievement, as Will explains:

„On a production processing 4–5TB overnight with a hard morning delivery deadline, any ambiguity in the handover would have cost time nobody had. Across a 20-week shoot, I averaged less than 15 minutes overtime a night.“

While efficiency is often measured by its impact on production, its effect on the people behind the workflow shouldn’t be overlooked, as Will highlights: 

„I had a newborn at home, so getting out on time meant I actually got to see her before she went to sleep (or we hoped she would). And of course it also keeps overtime costs down for production, which any line producer will tell you matters just as much as the rushes arriving on time.“

Final reflections 

While we’ve talked a lot about the technology that made this workflow possible, it’s only one part of the equation. Ultimately, even the best tools depend on the people using them and the decisions they make throughout the day.

“The most challenging part of the job is managing multiple stakeholders simultaneously. The DP wants the image to be right, production wants the schedule to hold, editorial want their material on time, camera department want their mags cleared. Every decision touches all of those at once.“

With that in mind, Will is clear about the role technology should play in the workflow.

“The kit and software are tools. The job is making everyone confident that their part of the pipeline is being looked after.“ 

Big thanks to Will for sharing these insights with us!