PBS has contracted IPTV to produce a documentary on the historic pubs of Dublin, Ireland and the trip has given us an opportunity to evaluate the Sony XDCAM.
I have been watching the rollout of XDCAM with great interest for the last few years as a logical next step for our move into non-tape based production. Ideally, evaluation of the technology and its applications at IPTV would have been targeted to begin in earnest next year, after we completed the construction of all nine of our digital transmitter facilities and the completion or our HD production studio rebuild, scheduled for completion in December. But people who have worked with me know that I am always willing to look at opportunities when they present themselves and adjust the plan to take advantage of the circumstances.
HDCAM VERSUS HDV
Since the crew are still in Ireland at the time I’m writing this, I can’t give the depth of coverage to how things went as I would like. There will be a presentation on the project at the Iowa DTV Symposium, Oct. 1-3 that will highlight how the production went and how we dealt with the differences between producing HD on XDCAM rather than HDCAM. I can give some of my initial reactions and a little bit of feedback from the field regarding the project and the equipment. But first, I have to thank Fred Wood, Peter DiIorio, Bill Fleming and the rest of the folks at Sony who not only agreed to lend us the gear but embraced the project as partners to ensure that the final production will be impeccable.
The camera supplied is a PDW-F350, which is the latest addition to Sony’s Cine Alta line. IPTV’s initial experience has been primarily with the standard HDCAM hardware producing 1080i content at 29.97 fps and we have been extremely happy with the quality of the content that we are producing. Quite frankly, our focus most recently has been on what place if any, the HDV format will have in our operation. There is a considerable price difference between XDCAM/ HDCAM hardware and HDV hardware and we wonder if the performance justifies the price difference. Based on my initial comparisons on the type of content that we produce and environments that we work in, I say yes. I based this on comparing the technical performance of the XDCAM and feedback from the operators with whom I have spoken.
A lot of the technological benefit is much more clearly identifiable in comparing the XDCAM with HDV than was apparent in our first generation HDCAM systems when compared to HDV. Improvements in the imager made between the HDW-700 and HDW-700A in the first year were fairly significant and the F350 is using three of the latest generation of HyperHAD 1/2-inch CCDs. The fact that the imagers are 1/2-inch as opposed the 1/3 inch (HDV) should not be overlooked; this is one area where size does seem to matter.
While working for KHON TV in Honolulu, I was responsible for the migration of the news and production field cameras from 2/3-inch tubes to 2/3-inch CCDs. During the transition, I pulled the existing lenses off the tube cameras and placed them on the new CCD cameras. No one was able to spot any of the performance issues that were presented because even though the tube camera lenses had performance issues at the edges that the tubes masked and the CCDs didn’t, the display devices masked them as well.
The reason I make this point is that we will soon reach a point where the average home display will be as sharp and accurate as any professional display and will be of a size that even the average viewer will start to see some of the aberrations caused by limitations of physics. In my mind the 1/2-inch imager and the associated lens offer the best price/performance combination. That’s not to say that a 1/3-inch system cannot approach the performance of the 1/2-inch but who is going to hang a $2,000 camera on the back of a $50,000 lens?
Another area where the XDCAM demonstrates an advantage over HDV is in compression. Recently, there has been an ongoing debate on the PBS Connect messaging system about the evils of compression. I tend to be much more philosophical about it and look at compression as a common tool. One of my hobbies used to be working on my MGs or Triumph sports cars. Any number of manufacturers made tools to repair the cars; some were cheaply made and didn’t work very well. They either broke or didn’t fit the fastener correctly and often resulted in skinned knuckles and colorful phrases being shouted from under the hood. So the first lesson is to make sure that the tools you are using are of good quality.
Occasionally I would find myself under the hood holding a socket wrench when I suddenly needed a hammer and I would then find myself using the socket hammer which frequently resulted in more skinned knuckles and colorful phrases. Lesson two, therefore is to use the appropriate tool for the job.
Compression is just a tool; make sure you use a good quality tool that is appropriate for the task at hand. The F350 offers one hour of record time on a single disk at 35 Mbps which even in first generation looked better to me than the 25 Mbps HDV. In our environment, starting out at the highest performance level possible ensures that as the content is manipulated, the finished product will maintain the highest level of quality possible. I do have to admit that even though I don’t view compression as evil, I like the fact that the XDCAM audio isn’t compressed at all since I tend to notice audio compression artifacts long before I see video compression artifacts.
One of the potentially cool features that I didn’t get a chance to play with before the camera left for Ireland is the FireWire interface. By using the FireWire connection and the appropriate driver, the camera can be plugged into a Windows based laptop and appear as another disk drive. I would think this would provide access to the MPEG-4 based proxy files and allow for logging and viewing content using any MPEG-4 compatible player or the Sony supplied proxy browsing software.
When the crew returns, the second part of the process will begin which is ingesting the material into our Avid Adrenaline editing system. Unfortunately, I cannot comment on the process and how it works until the crew returns. If the end users’ experience for editing the project is similar to the acquisition phase, I am confident that XDCAM will become an integral part of the IPTV production process.