1. Abstract
The notion that professional-quality video or films can only be produced by expensive and bulky cameras and finished on expensive post-production systems is over.
Today, even a smartphone has been successfully used by professional filmmakers to make feature films, while tiny point-of-view (POV) cameras are used for second camera footage (or B camera) in feature films, including 4K resolution footage.
The advent of 4K-capable DSLRs and mirrorless cameras have put professional quality in the hands of many people. Though a good quality film or video has less to do with the price or features of equipment, but more to do with a well-written story and an expressive cast, it is gratifying to know that equipment is no longer the inhibitor to the average person seeking to communicate through motion video. The success of online video streaming platforms such as YouTube or Vimeo means that more people are spending time watching video, rather than reading long blocks of text, or books.
Education is the same. It is difficult to engage students in a class unless an educator is exceptionally charismatic. It is far easier to present a good-quality video or film and discuss the salient points thereafter.
Let us explore some of the options of equipment, software, and techniques that are now more easily available to educators, and how best to think as a filmmaker and storyteller when approaching an educational topic.
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Table of contents:
- Abstract
- Introduction
- Understanding video formats
- Understanding polar patterns of microphones
- Understanding depth-of-field
- Basic video equipment for on-demand use
- Going further with live streaming
- Conclusions
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2. Introduction
Video is a medium that has consistently been a contender for education and training since the early days of non-linear editing (NLE), with suites such as Adobe Premiere 1.0 and AVID Media Suite Pro (MSP) on RISC-powered Macintoshes in the late 1990s.
More than a decade ago, video was recorded on magnetic tapes (VHS-C, VHS, MiniDV, Betacam SP, etc) and then the footage was digitized via FireWire connections. Digitizing the tapes into a digital format suitable for non-linear editing, editing them digitally on a computer, and then rendering the finished edit back to tape, were a test of patience, as computers were underpowered compared to today’s computers. Digital video that could be played back on computers directly was not high resolution either, as playback on client computers demanded far more computational power than most desktop computers could provide.
Therefore, video as a training or educational medium was confined to analog video tapes that had to be manually played and paused during discussions, or mastered onto proprietary and expensive laserdiscs.
Video became much more usable in both footage acquisition, editing, and playback, with the H.264 encoding algorithm, which eventually became pervasive on computers, smartphones, tablets, video cameras, and IP cameras (Internet protocol).
Today, hybrid cameras are capable of acquiring both still images and video, such as the Panasonic Lumix GH4, Sony A7, and Olympus OM-D E-M5 Mark II. Filmmaking has also become more affordable, with digital film cameras such as the Blackmagicdesign Pocket Cinema (BMPCC) and Digital Bolex, providing film-quality footage with high dynamic range that afford much flexibility to filmmakers and editors during the video editing and color grading stage. Even smartphones today are capable of capturing full HD (1920x1080p) quality, with some smartphones achieving 4K cinematic quality.
At the same time, the delivery platform has become much more sophisticated, with Google’s YouTube leading the way to populate video as the primary medium for social communication today, followed by other video platforms such as VIMEO, Instagram, Vine, Wistia, and so on.
According to a Cisco study (source: 2011), mobile video accounted for more than 271 million users and is slated to reach 1.6 billion users by 2016. Even in 2011, online video already accounted for more than 50% of Internet traffic, partly because video is a data type that takes up a lot of storage compared to textual or audio content, and demands even more from Internet connectivity.
For example, in July 2012, a virtually unknown Korean singer, Psy, suddenly became the global YouTube phenomenon with his Korean popular song (K-pop) “Gangnam Style”. Between July 15, 2012 to December 21, 2012, just a matter of months, his official music video on YouTube accumulated more than 1 billion views. And by April 2015, his official music video has accumulated more the 2.2 billion views. There were also many parodies to his song from all corners of the world, with many cover versions in various local languages.
List of most viewed YouTube videos: http://en.wikipedia.org/wiki/List_of_most_viewed_YouTube_videos
In 2011, a radio DJ Hooman Khalili and Patrick Gilles used a Nokia N8 mobile phone to shoot a full-length family film “Olive” (http://www.imdb.com/title/tt2125574/). The film was a poignant and delicate portrayal of a young girl who did not speak at all, but helped a few people transform their lives through her mysterious powers. Although the mobile phone was rigged to some professional attachments and rigs, the efforts of the “Olive” team showed that filmmaking has truly leaped forward, and that everyday smartphones and affordable hybrid cameras have brought good quality storytelling through the video medium not just a possibility, but a reality.
Media mention: http://www.theguardian.com/film/2011/dec/02/olive-film-shot-on-smartphone
3. Understanding video formats
In the early years of video, whether analog or digital, the pre-dominant resolution was the VCD format, which when translated to pixels, measures 352 horizontal pixels. The later DVD format measures either 704 or 720 horizontal pixels (source: http://en.wikipedia.org/wiki/DVD-Video).
Moving up, the HD (high definition) format is split into 2 formats, HD, and full HD. The HD resolution is 720p, or 1,280 horizontal pixels by 720 vertical pixels. The full HD resolution is 1080p, or 1,920 horizontal pixels by 1,080 vertical pixels.
Larger video formats are intended for cinema applications, such as 2K (2,048 horizontal pixels by 1,536 vertical pixels in the 16 mm format), and 4K (4,096 horizontal pixels by 2,214 vertical pixels in the 35 mm 1.33 aspect ratio format) (source: http://www.videotechnology.com/0904/formats.html).
4. Understanding polar patterns of microphones
For audio acquisition, we need to understand microphone polar patterns, namely: omnidirectional, cardioid, and figure-8 (or bi-directional) (source: http://ehomerecordingstudio.com/microphone-polar-patterns/).
If you like to record video for a live event, such as a round-table discussion where your microphone has to pick up multiple voices or audio in all directions, or live large room performances (such as an orchestra), then you can use a recording microphone with an omnidirectional polar pattern.
If you like to record video for a stage performance where the main voices and audio come from a more concentrated source, or rooms with poor acoustics (such as concrete rooms with no audio-softening materials such as thick curtains or carpets), then a microphone with a cardioid polar pattern would work.
If you want even more audio isolation and thereby shutting more ambient noise while using a microphone at a distance, then a microphone with a figure-8 polar pattern would work. Remember that the figure-8 microphone (usually known as a “shotgun” microphone) does pick up audio in the opposing direction (usually towards you, the user), and so you must reduce noise from you the camera or audio handler.
Some omnidirectional microphones, despite having audio pickup in all directions, may actually work well to isolate vocals from the ambient noise. These specific microphones are Lavalier microphones which are often used by broadcasters, and can be wired, or wireless. They can work in environments with ambient noise simply because their proximity to our voice is very close, and therefore the signal-to-noise ratio (SNR) is manageable enough for us to pick up sufficient vocals despite the background noises.
5. Understanding depth-of-field
In an educational context, the notion of focus may be important.
For example, if we want to illustrate the assembly of a smartphone through video, then our visual focus should zoom in to smartphone being assembled, rather than on the background or the foreground. The technique to “blur out” the background from the subject or object in question, is often achieved with a shallow depth-of-field (DoF).
A typical removable lens on a hybrid camera has 2 sets of adjustable attributes, the distance (which determines focus), and the aperture (which is expressed in f-stops).
So, a lens may show f-stop values from 2, 2.8, 4, 5.6, 8, 11, 16, and 22.
If an image is acquired at F2, the background will be blurred against a sharp foreground subject or object. This is due to a shallow depth-of-field (DoF) at F2.
Conversely, if the lens is at at F22, the aperture becomes very small, and invariably not only the foreground will be in focus, the background will likely to be in focus too. In this scenario, since both the foreground and the background are both in focus, then the viewer may be more distracted because of the background.
Therefore, whenever possible, it is ideal to have as shallow a DoF as possible, and this often means using a prime lens, rather than a zoom lens. If the location is large, then it may be possible to use a prime lens that is more telescopic. If the location is small, then a wide-angle to normal lens may be more suitable.
6. Basic video equipment for on-demand use
What kind of equipment should an educator choose when producing video content for on-demand use?
Remember, it is not about having expensive gear, but how we tell a story well.
Typically, a hybrid camera, such as a mirrorless interchangeable lens camera, such as the Panasonic Lumix GH4, Olympus OM-D E-M5 Mark II, would be best. There is little reason to go for more expensive (though more capable) cameras since both of these cameras produce very good still images and video. Both these cameras are capable of accepting external audio through a 3.5mm audio jack, which means that you can plug in powered microphones, including wireless lavalier microphones, for much higher audio quality otherwise unobtainable through the on-board microphones. The Panasonic Lumix GH4 also features a headphone jack so that you can monitor the audio you are recording, while the Olympus E-M5 Mark II requires an additional HLD-8G external grip to get a headphone jack for monitoring audio. The Panasonic Lumix GH4 trumps the Olympus E-M5 Mark II by shooting 4K resolution as well. If you want to shoot in a “run-and-gun” format where you are moving with your camera and the camera is not mounted on a tripod, then the Olympus E-M5 offers a 5-axis image stabilization technology that can provide you with very steady footage. The Panasonic GH4 requires stabilized lenses which can be more limiting.
However, it is entirely possible to go for bridge cameras, which have zoom lenses but these lenses are not interchangeable. For example, the Panasonic Lumix FZ1000 or the Sony RX10 are good choices. Both of these bridge cameras, also feature 3.5mm audio jacks for you to plug external powered microphones into. Both the Lumix FZ1000 and the RX10 are image stabilized bridge cameras.
If however, you intend to use a smartphone as your image acquisition device, then the Microsoft Lumia 1520 and Lumia 930 are good smartphones that offer very good small-sensor cameras for video, since these smartphones have built-in optical image stabilization. The Sony Xperia Z3 and LG G3 offer very good optics with optical image stabilization too, running the Android operating system. The Apple iPhone 6 and 6Plus are good for portable video acquisition too, with what Apple terms as “Cinematic Video Stabilization”, some form of software-based video cropping and stabilization algorithm that works very well too.
http://www.microsoft.com/en/mobile/phones/all/
If your camera or smartphone does not feature built-in image stabilization (either by software or hardware/optical), then you may need to mechanically stabilize your camera or smartphone. This is typically achieved by mounting your camera or smartphone onto a tripod. A smartphone typically does not have a tripod mount, and you may need a small adapter that allows your smartphone to be mounted onto your tripod. There is typically no need for a heavy-duty tripod as you are likely to use a consumer or prosumer camera, or a smartphone for video acquisition.
While most cameras today feature HD video, and even smartphones today feature HD or even 4K video, the weakest link is often the audio.
In most consumer or prosumer cameras and smartphones, the on-board microphone is typically of average or below-average quality, and will not offer you a good signal-to-noise ratio that brings out the vocals in your video.
Therefore, some kind of external microphone should be linked to your camera or smartphone.
The caveat is that not all consumer cameras have an input port for audio (a 3.5mm audio-in jack). It is advisable to select only consumer or prosumer cameras that have audio-in capabilities. Smartphones typically have an audio jack that can be used as a microphone-in jack.
For most purposes, a powered microphone is required, as unpowered microphones typically have very weak audio signals. A good “shotgun” microphone is best for our purposes, to record vocals of trainers or professors.
Next, we will need to find a way to import our video footage into a computer, and then use a non-linear editor (NLE) software to edit the footage into a completed video. For educational purposes, we do not need to use the NLE to have special effects or extensive editing – just “cuts-only” videos will do.
Once we complete the editing of our video, we can output the finished video to industry-standard formats, such as MP4 (MPEG 4). Most online video hosting platforms such as YouTube or VIMEO will accept MP4 formats.
7. Going further with live streaming
Some educational video content can be streamed live to audiences around the world. With YouTube and other comparable live streaming options, live streaming of video content is now within reach.
First, for live streaming of video, the camera must offer a clean HDMI-out signal. Some prosumer cameras offer a HDMI-out port, but cannot output clean HDMI signals. A clean HDMI signal is one where the video signal is directly output through the HDMI output port without going through the internal compression-decompression (codec), usually providing a higher quality video signal. This signal is usually streamed to a HDMI encoder that is wirelessly connected to the Internet, and the video feed is then compressed “live” by the hardware encoder to a remote web server that can interpret the live video signal, and then presented to audiences using the RTMP streaming protocol (realtime messaging protocol) with a web browser (which can be viewed on the desktop, tablets, or smartphones).
Usually, the HDMI encoder is connected to the Internet via WiFi, although there are some encoders capable of connecting to the Internet via 3G/4G LTE cellular networks.
For smartphones, there may be no necessity to use a HDMI hardware encoder, as most smartphones allow live streaming directly via its own built-in WiFi or through 3G/4G LTE networks. Although the video feed may not be as adjustable as a good quality camera, the smartphone may suffice for most educators.
8. Conclusions
In the new economy, more people are learning by self-directed means. The emergence of advanced and increasingly miniaturized smartphones and cameras capable of acquiring good quality video has brought about the empowerment of everyday people, including educators. It is no longer necessary to rely on expensive equipment, or large crew, to acquire and stream video content to learners.
The pace of improvement of such equipment is quickening, while the costs are decreasing. The shift from learners merely reading textual content to viewing video to a large extent, means that educators have to adapt to a changed learners’ world, where video will be key.
(PS – This paper was based on my “live” delivery to educators and marketers in separate occasions).
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