Jeff Greenberg from Videography /
02.14.2014 03:54 PM
Adventures in 4K Acquisition
DOVER, DEL.—Though the adoption timeline is debated, 4K is clearly the future (high-resolution pun intended). In the next few years we’re going to see more high-end editorial shops and post facilities adopt 4K workflows to remain competitive in their markets. As the industry embraces the format, there are still a number of hurdles to overcome with regard to the production chain, primarily acquisition and drive bottlenecks.
Jeff Preston shoots at Bowers Beach, Del.

The editorial part of the chain already works. All the current versions of the major NLEs (Adobe, Apple and Avid.) handle 4K directly in some way. Even though Avid Media Composer can’t output 4K at this time, there are strong workflows that permit a full 4K output with Blackmagic Design DaVinci Resolve.

Delivery and display pose challenges. If your client wants to see an HD master in 4K today, it can be difficult and it’s going to be a challenge to deliver. How is your client going to evaluate a 4K H.264 file? And what about you? Right now, it’s likely that you don’t have a calibrated 4K monitor—and your clients certainly don’t (although the native display of a MacBook Pro with Retina display comes close). Monitoring in HD on a calibrated system is a similar compromise that resembles the HD/SD monitoring before HD monitoring was affordable. Of course, checking the focus at 100 percent is vital.

But I want to emphasize the front of the chain: acquisition. We’re talking about large data acquisition. While I love raw workflows, primarily for the flexibility they offer in color grading, most often they’re cumbersome for data piping and storage. That’s where technology developers like AJA are stepping in with cost-effective solutions engineered to simplify 4K workflows.

Of course, these images look much better in post on calibrated monitors—even in HD.

The Ki Pro Quad in particular makes 4K acquisition a manageable endeavor. I recently experienced this firsthand while preparing footage for an Inter BEE presentation for Canon and G-Technology on the topic of maximizing performance for 4K workflows.

For the project, my good friend and veteran DP Jeff Preston (DP/producer/editor at Visual Innovations) and I designed and implemented a 4K workflow based on AJA’s Ki Pro Quad. Our aim was to capture the highest-quality footage possible (we used a Canon EOS C500) and push it through every one of the NLEs I use—Apple Final Cut Pro X, Avid Media Composer 7 and Adobe Premiere Pro CC, as well as a few common compositing and finishing tools—to see how the footage and the software would perform together.

AJA Ki Pro Quad connections

One of the first decisions to make was whether to capture raw and, knowing how unwieldy it could be, how much of it. I also needed to design a less demanding workflow than pure raw, which is how I arrived at using the ProRes 4444 codec. It would give me “almost” full raw quality, so I’d have the flexibility to see how far I could push the footage in color grading. The Ki Pro Quad and Canon EOS C500 were a natural fit for this project. With them, we’d be able to record any flavor of ProRes, and also gather a few raw shots as test footage.

With our C500 and Quad in hand, Jeff and I began the test. We shot footage in three different locations for variety: a farm by the side of a road, a beach at sunrise and a state park. (We actually recorded some footage of my daughter, just so I could say I was the first person to shoot a home movie in 4K.) In each environment, we connected the Quad to the C500 with a single 3G-SDI cable. It mounted beautifully behind the camera. The Quad was able to debayer the camera’s raw footage while simultaneously encoding it into a log ProRes file, preserving as much dynamic range as possible for the compressed file format.

Ki Pro Quad 4K workflow with raw camera data

It’s rare in this business that you unpack a piece of hardware, plug it into another device and it just works. Usually adjustments need to be made or troubleshooting is involved, but with Quad, I plugged it in, hit record and I was capturing 4K ProRes 4444 footage. The default settings were ideal, and the C500 auto-trigger features built into the Quad were spot-on.

The Quad’s design made it easy to get up and running. Once you’re recording, the confidence monitor on the device gives a quick reference of the input signal, along with access to all operating menus. The HD-SDI and HDMI outputs permit the user to monitor at 4K and HD resolutions simultaneously, so we could ensure the quality of our footage throughout filming.

I was impressed by the Quad throughout the shoot, even when it came time for the gutsiest part: capturing 4K raw footage. I had installed AJA’s CamXchange software on my MacBook Pro prior to our shoot. To record uncompressed raw footage directly to my laptop, all we had to do once we were on set was plug the Thunderbolt cable from the Quad into my MacBook and fire up the software. It was almost unbelievable that we could look at uncompressed footage like that. It’s not every day that you get to play with raw material. For most workflows, you will want to attach a RAID or other appropriate storage to your CPU for best performance with the resultant uncompressed DPX files, especially on larger projects.

We never did try plugging in the audio.

The Ki Pro Quad took the uncompressed raw data coming across the SDI output from our C500 and transferred it over Thunderbolt to my laptop in real time. On top of that, all of the raw files created by the CamXchange application on my computer mirrored my ProRes QuickTime file names, meaning they’d be ideal for proxies. I couldn’t believe it; I’d expected the process to be five times more complex. If I were going to create a raw/proxy workflow, I’d use a less demanding version of ProRes, such as ProRes 422, just for the lower data rate.

By the end of the shoot we’d acquired 30 minutes of ProRes 4444, which took up close to 350 GB on our AJA Pak media (an SSD that slides into one of two slots in the Quad), and raw footage captured to the laptop. Once filming wrapped, I plugged the AJA Pak Dock SSD media reader into my MacBook via Thunderbolt, removed the Pak drive from the Quad and inserted the drive into the Dock. I was then ready to test in Apple Final Cut Pro X, Adobe Premiere Pro CC and Avid Media Composer 7, along with Adobe SpeedGrade and Blackmagic DaVinci Resolve.

When capturing raw, CamXchange matched the raw files to the QuickTime media, making a proxy workflow easy.

This 4K workflow wouldn’t have been possible without Ki Pro Quad. While the EOS C500 camera shoots in 4K, it captures only to HD without external hardware, and it’s pretty compressed. To capture 4K with the C500, you need to come off of its camera port using an external recorder. The Ki Pro Quad’s specs made it my go-to choice. It’s evident that AJA engineered the recorder to meet the needs of users in real-world production scenarios. I simply plugged a single cable into my C500 and it worked the first time, right out of the box. As a post pro, you can’t really ask for more than that.

The Ki Pro Quad is a piece of quality hardware that made my 4K production experience an enjoyable one. If image quality is important, then you can see why you’d want to work with a pure 4K signal. The device effortlessly recorded into ProRes, and performed admirably on the extra-special shots that required true raw. For those choosing the 4K path, Ki Pro Quad works like a champ.

Jeff Greenberg is a postproduction consultant and master instructor for Adobe, Apple and Avid, with nearly two decades of experience in editorial, compositing, sound, color grading and compression. He’s the chair of the Editor’s Retreat, a yearly getaway for editors by editors.

 


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