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T356 2013 - Week 14
Announcements/Reality Check
Agenda
New Trends in Multi-Camera Studio ProductionMore and more TV studios are using motion control cameras, flourescent and LED lighting, and virtual sets. Multi-camera field production is incorporating camera mounts which allow for more interesting angles and dynamic shots. Motion Control Camera Controls: Shows that have elaborate openings are often programmed with elements such as robotic camera support. This provides a way to use repeatable and complex moves easily. Vinten's robotic-controlled pedestal:
Virtual Sets
Lighting More and more studios are using flourescent lighting and LED fixtures. These are more efficient than tungston/halogen lighting. Cable-mounted cameras: 2K & 4K HD is great but there's something even better: 2K and 4K. Check out the wikipedia entry on it.
2K provides only slightly more information than HD. 2048 pixels per line compared with 1920. But the format was embraced by the digital cinema industry. The Phantom Menace introduced the world to Digital Cinema. Digital Cinema is not about production- but the distribution of theatrical content. Most have ignored 2K and focused on 4K, which essentially provides 4 times the information as HD. Just as HD comes in varying pixel dimensions for broadcast and recording 4 comes in different sizes as well. Most variations of 4K have 4096 pixels per line.
Format ConversionVideo production editors and producers have to deal with a number of different media formats and need to understand the physical distinction between them. You can get from one format to another by using a number of different hardware or software converters. Companies like Snell & Willcox make conversion boxes. Panasonic makes a multi-format conversion VCR (PAL, SECAM & NTSC). After Effects, Final Cut Pro and a number of other pieces of software allow for electronic conversion. However one still needs to make sure the media is delivered using the correct format and matching medium. Some of the different formats include film, standard definition and high definition versions of NTSC, PAL, 16 x 9 and 4 x 3. NTSC (National Television Systems Committee) definition of standard definition TV, (used in North America, some of South America, Japan, etc) uses a frame rate close to 30, roughly 29.97 frames per second. There are 525 scan lines; approximately 480 of these are visible. The HD (high definition) standard for broadcast has been created by the ATSC, the Advanced Television Systems Committee, which was formed at the urging of the FCC to establish standards for the new high definition formats. PAL (Phase Alternate Line) is used in most of Europe, Australia, & Asia and runs at 25 frames per second using 625 lines. SECAM (Sequential Color and Memory) If possible it’s best to edit in the media’s native format. If you have high-quality PAL footage, it’s best to try to keep it in PAL. If you have 24 fps footage, it’s best to keep it in 24 fps. That way you won’t get conversion artifacts from changing frame rates and generation losses. But while ideal, we can’t always practice this. Often we’ll get a tape from another country, or that contains another type of media that must be integrated into our existing content. Film to Video When converting film to video we use a 3:2 Pulldown See Film runs at 24 frames per second. 24p refers to video shot at 24 frames per second progressive- that means there are no fields. Since film runs at 24 fps and video runs about 30 fps, the two aren't directly interchangeable at least on a frame for frame basis. (To be more precise, 23.976 film frames become 29.97 video frames.) In order to transfer film to 30 fps video, the film frames must be precisely sequenced into a combination of video frames and fields. A telecine is a piece of hardware containing a film projector sequenced with a video capture system. The telecine process is a term used to describe the process of converting film to video, also called a 3 2 pulldown. In the 3-2 pulldown each frame of film gets converted to 2 or 3 fields of video. Note how 4 (24fps) frames are converted to 5 interlaced frames (30 fps) in this 3-2 pulldown:
Another way to look at it:
DTV (Digital TV broadcasting) A number of industry associations, corporations, and educational institutions formed the Advanced Television Systems Committee (ATSC) in 1982. The ATSC is a not-for-profit organization that develops voluntary standards for advanced television systems (www.atsc.org). Such advanced systems include enhanced analog TV, digital TV (DTV), standard definition TV, high-definition TV, and data services. The ATSC’s published broadcast standards are voluntary unless adopted and mandated by the FCC. In December 1996, the FCC adopted most of the standards proposed by the ATSC, mandating that broadcasters begin broadcasting digitally. According to the ATSC, within one year of the November 1, 1998 rollout, more than 50 percent of the US population was in a position to receive digital broadcasts. During a transitional period, television would be broadcast both digitally under the FCC’s digital terrestrial television (DTT) guidelines and through traditional analog means. At the present time, Congress has voted to terminate analog broadcasting by February 2009, though the deadline could be extended. You can squeeze 4 SD programs in the same space used to broadcast one HD program. Both use MPEG-2 compression. Digital TV Systems:
Further resources: SD vs. HD Standard definition television (SDTV) can use either the 4:3 or 16:9 aspect ratios, HDTV always uses the 16:9 aspect ratio.
Beside having more pixel resolution, HD can display much more information in terms of color and brightness. HDTV While HDTV content is designed to fill a 16:9 frame, the display of programming from other sources with varying aspect ratios is also possible. Programs shot in the 4:3 aspect ratio or in wider, cinematic formats can easily be displayed inside of a 16:9 frame without distortion by shrinking the image. Unfortunately it’s quite common to see broadcasters delivering images with the improper aspect ratio (Example A of figure 2.3). Traditional, 4:3 content is ideally viewed on widescreen displays by presenting the image as large as possible, centered within the frame. (Example B) This is sometimes referred to as pillar boxing. This allows the original image to be seen as it was intended. Some broadcasters magnify the 4:3 image so that it fills the entire 16:9 frame. (Example C) This can often be identified by the lack of headroom. Content from cinematic formats with wider aspect ratios can be accurately displayed within the 16:9 frame with letterboxing. (Example D) It’s also frequently necessary to present widescreen programming inside of traditional 4:3 displays with letterboxing.
Metadata & Closed Captioning Metadata is embedded information about the program itself (such as the title, running time, production notes, etc). Closed-captioning is text that can be displayed on screen for the hearing-impaired. Carried in the vertical blanking interval, the FCC mandates that all stations broadcast programming with closed captioning data. In addition, with the advent of interactive or enhanced TV, there is quite a bit of information that can be packaged within the video signal. For instance you might want to embed information on products, actors, production notes etc into the program content, which, with the right systems be viewed by viewers with interactive-capable sets. Avid makes Metasync, a product which let's editors work with this data right in the timeline. If you watch closed-captioned programming, you'll see a variety of levels in terms of readability, placement and proper duration. Companies like Soft NI create stand-alone subtitler systems that let you integrate subtitles into a video stream. Adding subtitles involves proper placement on the screen. Softel-USA makes products for subtitling HD programming. Vocabulary (Know these terms)
Up to Jim Krause's T356 homepage
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