Multimedia Devices

Multimedia is any media and content that goes beyond the traditional printed or hand-produced material.  Pictures, video, audio, and even computer animation are often used to enhance the storytelling process.  And after all, whether writing a novel, capturing a history, or presenting a news article, it all really just boils down to storytelling.  The first key, then, is to keep the story and the audience in mind.  Choose the media that best fits the story and audience and half the work is done.

Audio

While a picture is said to be worth a thousand words, we remain heavily reliant on quality audio.  For instance, watch a video presentation in which frames of images are sometimes lost and it is still possible to understand the crux of the message in most cases.  But watch that same video presentation with a few seconds of audio lost and it becomes increasingly difficult to capture the full message.  Cell phones, integrated devices like smartphones, inexpensive camcorders, and still cameras generally do not have the ability to capture audio well in any but the most ideal environments.

Here are a few quick recommendations to assure quality audio capture.  When recording audio on a computer, consider using an external microphone.  For individual recordings, use a headphone/microphone combination headset.  Even a relatively low cost version will help considerably to reduce the noise from computer fans, typing on keys, and a range of other background noises.  More expensive versions add noise cancellation to the microphone to further reduce background noise, and also provide greater sensitivity to capture the full range of voice of a great storyteller. A reasonable quality headset can be purchased for under $25.00 USD, while a high end headset can cost $100 USD or more.

For recording two or more people, a USB microphone is ideal.  A quality USB microphone will provide quality recordings for everything from a soft whisper to the loudest garage band.  For increased flexibility, choose a microphone that can be reconfigured to either record from a limited direction (cartoid recording pattern) or from a full 360 degrees (omnidirectional).  Expect to pay $75-$100 USD for a good USB microphone.

As with computers, using an external microphone with other devices will greatly increase their audio recording capabilities.  Most netbooks and many integrated devices provide some means for attaching an external microphone. Some camcorders also include external microphone options.  In most cases, external microphone inputs will be provided either through a 3.5mm input jack or a proprietary port.  The 3.5mm input jack is a widely supported option that provides considerable flexibility in microphone choice.  The proprietary ports, on the other hand, are more restrictive and are often mean only more expensive microphone options are available.  Some proprietary attachments, though, often include 3.5mm input jacks to open up greater flexibility.

A detailed look at microphones can be found at:

http://www.mediacollege.com/audio/microphones/how-microphones-work.html

Recommendations for audio recording equipment can be found in the Do-it-yourself instruction guide provided by StoryCorps at:

http://storycorps.org/diy/participate/

Still Images

For still images destined for the web and taken in good lighting conditions (outdoors or a well-lit room) a modern cell phone, computer webcam, or camcorder are all now able to take adequate pictures. Even a modestly prices camera, though, provides valuable features such as optical zoom, image stabilization, and increased light sensitivity for low-light situations.  Higher priced point and shoot cameras add increased control over the camera, allowing the photographer to manually control aperture, shutter speed, and sometimes even focus.  Increasing in price further, digital single lens reflect (SLR) cameras and SLR-like cameras include interchangeable lenses and the most control.

As a quick recommendation for a camera available in a collaborative space for most basic photography situations, look for a simple point-and-shoot camera with the following features:

  • At least 10 megapixels (MP).  This will allow reasonable 11×17 prints of originals and also 4×6 to 8×10 prints of cropped images (using software to digitally zoom into a select portion of the picture).
  • Image stabilization.  This is important to assure that slight shaking of the camera, including when the shutter button is depressed, does not result in a blurred image.
  • Optical zoom.  The ability to bring distant objects closer is best done with an optical zoom, in which the lens of the camera mechanically changes to adjust focal length.  This is compared to digital zoom, in which the camera selects a portion of the recorded image in which to store, but in so doing reduces the overall pixels stored for that image decreasing image quality.  Some cameras also include the ability to take wide-angle photos which can be valuable in capturing panoramic views.
  • Easy selection of auto and advanced modes.  For those who just want to pick up the camera and take decent pictures, the auto mode is very important.  But to support those who want to begin a foray into more creative photographic expression, the advanced mode allows for at least some control of aperture and shutter speeds.

Additional features that might be considered when purchasing a basic point-and-shoot camera include:

  • Maximum aperture.  A camera that can take decent indoor pictures without flash will have an f-stop of around f2.0 (the smaller the f-stop number, the greater the opening to let in light).  An added advantage of a low f-stop is that it can decrease the depth of field, keeping the main part of the image in focus but blurring the foreground and/or background.
  • Burst mode.  Some cameras allow multiple images to be taken with the single depression of the shutter button.  How many pictures taken per second varies based on a range of factors including shutter speed and the speed of the flash storage device.  But an ability to take several pictures per second can help capture the moment when no one was blinking or the highlight of an action scene.
  • Battery options.  Cameras either use standard AA batteries or proprietary rechargeable batteries.  A camera that uses AA batteries makes it easy to carry around or buy spares if you find yourself with dead batteries and an immediate need to take pictures.  But AA batteries typically can’t take as many pictures before needing to be changed and unless you use rechargeable versions aren’t as environmentally friendly.

For more on digital camera features, check out:

http://photo.net/equipment/digital/basics/

Video

Using a cell phone, still camera, or inexpensive pocket camcorder can work just fine to catch simple action shots destined for sharing in a window on your computer.  Of these, only still cameras typically include image stabilization and optical zoom.  Overall, while improving these devices provide only low to mid-quality videos.

Dedicated camcorders provide several options that are optimized for video and result in higher quality video recordings.  The first is the quality of the lens.  Canon is known for their high quality lenses, while Sony and Panasonic use well known Carl-Zeiss and Leica lenses, respectively.  The second is the imaging device, which on most camcorders sold today is referred to as the CCD.  The highest end camcorders use one CCD for each of the three primary colors (red, green, blue), which is why their color fidelity is so much better.  They also use bigger CCDs (1/3” compared to 1/6” found on compact home camcorders), requiring larger camcorders but producing more vibrant colors in indoor and other low light recording environments.  The third is recording format.  The highest quality video recordings are still achieved using mini-DV tapes and is the only recording format available today that allows frame-by-frame editing.  In addition, the mini-DV tapes can provide a valuable mechanism for archiving recordings.   Tapeless camcorders store MPEG-2 or MPEG-4 format to flash memory, hard drives, or mini-DVDs.  However, because of image compression used in MPEG to reduce size, image quality is sacrificed.  On the other hand, MPEG formatted media can be played directly on computers, while the DV format must first be imported in real-time (10 minutes to import a 10 minute video).  We have found that in most cases the hassle of importing from mini-DV tapes isn’t worth the quality gain when using an entry-level camcorder except for special needs like archiving historic artifacts where image quality is of major importance.

Today both standard definition and high definition camcorders are widely available to consumer markets.  When capturing images, cameras and camcorder takes samples at regular intervals.  The result is a grid of pixels that can be specified by the number of columns and the number of rows within the grid.  Standard definition images using the standard 4:3 display have 640 columns and 480 rows (640×480 display).  A widescreen 16:9 display has 720 columns and 480 rows (720×480 display). High definition videos are either 1280×720 or 1920×1080.  In a window taking up a portion of a computer screen, either will display OK.  Even in full screen on a standard computer monitor or TV, a standard definition video will display most objects OK.  High definition becomes valuable when it is important to effectively capture small objects or when wanting to show high quality video to very large displays.  Still, a low quality pocket camcorder or still camera taking high definition images will likely have an overall poorer display than a mid-level full-sized standard definition camcorder.

Important Side Note Regarding File Compression

Compression is the process used to decrease the overall filesize of audio and video recordings.  A simple way to think of compression is to consider the number 25.77777777.  This number is comprised of 11 distinct characters.  If each character is one byte, storing this number as is would take 11 bytes.  But we could also use shorthand to store the eight 7′s in a row as [8]7, making the number 25.[8]7 or 7 distinct characters.  We could also round off the number to 25.7778 (7 distinct characters) or even 26 (2 distinct characters).

By changing notation or by rounding, we reduce or compress the amount of data stored.  In changing how we write the number, we compress the data in a way that doesn’t loose any information.  That is, we can reproduce the number just as it was originally captured.  In rounding, we loose a little or a lot of detail, but can potentially significantly reduce the size of the file.

All cameras and camcorders perform some level of compression by default.  For some devices, the level of compression is selectable.  For instance, many cameras allow selection of image quality (as opposed to selecting recording pixels).  Increasing the quality increases the file size but also means the reproduction of the image will be closer to the original image captured by the camera.

On camcorders, selecting the bit rate per second determines the level of compression.  Higher quality videos are typically captured at around 9-10 Mbps (megabits per second), while lower quality “long play” videos are captured at around 3 Mbps.

With video, it is also possible to compress images between frames by only capturing the portions of subsequent images that changed from the first image.  This further reduces video size but can subsequently impact video editing.  Only miniDV video recordings do not compress images between frames, increasing their overall video quality and making possible frame-by-frame video editing.

Leave a Reply

Your email address will not be published. Required fields are marked *