HDR and Immersive Audio Dominate SMPTE Conference
The 2015 Annual Technical Conference and Exhibition of the Society of Motion Picture and Television Engineers (SMPTE) drew record crowds to the Loews Hollywood Hotel in Hollywood, CA, 26-29 October 2015.
A packed agenda of presentations from the industry’s leading experts was dominated by Ultra HD topics, particularly high-dynamic range (HDR), wide color gamut (WCG) and high frame-rate (HFR) video, and immersive/personalized audio topics. Facility conversion to IP-based technology was also covered in depth, along with the latest in file-based media workflows.
Other topics included video compression technologies, archival storage and recovery, cybersecurity in media production facilities, and over-the-top (OTT) TV distribution. A session on the development and status of ATSC 3.0 was also featured.
The annual pre-conference Symposium on 26 October covered Virtual and Augmented Reality, including a roomful of interesting demos.
A new item at this year’s conference was the SMPTE-HPA Student Film Festival, a juried competition in in which a dozen finalists vied for best in show in three technically oriented categories: Best Creative use of Technology to Engage the Audience in the Story, Best Portrayal of Entertainment Technology in the Film-Documentary Format, and Best Creative Use of Virtual Reality in Storytelling.
Exhibit space was sold out, resulting in overflow areas being set up to host the 80+ exhibitors on hand.
The recent merger of SMPTE with the Hollywood Post Alliance (HPA) was also in evidence, with cross promotion of upcoming HPA events throughout the conference.
Among the most interesting new findings reported during the coverage of Ultra HD video technologies were the interactions of various UHD components. For example, one presentation pointed out that as luminance and screen size increase, they also increase the perceptual effects of flicker. Higher luminance also increases the perception of hue shifts.
Human perception was deeply explored, including our vision’s adaptability to a wide range of ambient light conditions, and the time it takes for that adaptation to occur. One presentation reported that at any given time, human vision perceives the equivalent of 14 f-stops, but that 14-stop range can slide over a broader absolute range given adaptation time of 30 to 60 seconds. Another presentation considered how human perception might react in a mixed world of high- and standard-dynamic range video, such as might be encountered on a given television channel or service during the Ultra HD transition period, as HDR and SDR content changes between programs and interstitials, or across channel-changes, or even in flipping between guide screens and content.
Several papers addressed the new challenges faced in lighting for Ultra HD productions. For example, with a given imager size (e.g., 2/3-inch), moving from HD to 4K video loses two f-stops of sensitivity (due to the smaller pixel size). Similarly, going from HD to 8K loses four f-stops. Moving to higher frame rates and smaller shutter angles also reduces light available to the imager, on the order of one f-stop lost for every doubling of frame rate.
On the other hand, it was noted that HDR cameras have the inherent fringe benefit of providing higher luminance headroom, which can be useful in live work (especially in the field), thereby reducing the occurrence of overexposures, and requiring less camera-control manipulation in live control rooms.
A related benefit of HDR camera development is increased sensitivity in low-light environments. One impressive demo from Canon showed its ME20F-SH, a specialized low-light camera, operating at the equivalent of ISO 102,000, producing reasonably low-noise HD images with accurate color rendition. Rather than a “night-vision” effect, the resulting video was near-broadcast quality. The camera accommodates standard lenses and output interfaces, and has a maximum sensitivity of greater than ISO 4,000,000. The clever demo of the camera placed objects at the back end of a light-insulated tent, with the front of the tent left open to allow attendees to peer inside. The objects at the back of the tent were obscured by the darkness and rendered completely invisible to the naked eye, but a video monitor fed by the camera looking into the tent revealed the subjects clearly (see photo below). For skeptics, the demo staff shined a flashlight into the tent to show that the objects were indeed present at the rear of the tent.
Numerous demos and papers presenting the currently competing formats for HDR kept the event interesting. There was also more evidence of the subjective value of HDR’s addition to HD (1080p) video, which has been increasingly reported throughout the industry. This led some to conclude that Ultra HD might need to be defined as “anything that is better than HD,” such that 1080p with HDR is as much an “Ultra HD format” as 4K video. Perhaps the ultimate takeaway from the conference was therefore that Ultra HD is clearly coming, but what it includes, or precisely how it’s defined (including its audio capability), remains unspecified at the moment.