6 Things
You Need To Know About Document Cameras
Remember the days when high-tech presentations were limited to overhead
projectors and transparency
sheets? Today, technology has given birth to a wide variety of options such
as document cameras.
Also known as visual
presenters or Elmos (though Elmo is a specific brand name), document cameras
allow educators, court room attorneys, or anyone who wants to give an effective presentation the
right tool to do so. Read below for more information on how to choose the perfect
document camera option for you.
Connections
How do you want your presentation
to be viewed?
- Data Projector (the most common display method)
- Large enough for number of people to view it comfortably
- Computer Monitor
- Good for small meeting rooms or If there is no access to data projector
- Use images with software such as PowerPoint
- Switch from computer images to document cameras with a touch of a button
- Television Screens
- Good for small meeting rooms
- or if no access to data projector
Portability
- Fixed Installations
- Great for using on a stage or in a library
- Generally full-featured
- Variety of options
- Portable Document Cameras
- Greater Mobility
- Basic to fully-featured models
Resolution
The resolution of the document camera you choose will determine the quality
of the image that is portrayed.
Measured by
- number of lines
OR
- number of pixels (most common)
Document cameras are categorized
by their resolution in the same manner as data projectors.
It is important to match your document camera resolution, or input
resolution, with your output resolution, whether it is a data projector or a
computer monitor.
While not directly related to resolution, frame rate has a great impact on
the overall appearance of the image.
- Frame rate is the number of times the image
refreshes per second and is often referred to as fps (frames per second).
For
example, a presenter that refreshes 30 frames per second will have much smoother
movement than one that refreshes 15 frames per second.
Zoom
There are three ways to make objects appear larger when using a document
camera.
- Bend the gooseneck so that the head is physically closer to the object
- Optical zoom involves a physical movement
- no degradation in quality of image
- may be more expensize
- Digital zoom resamples the image to
make it appear larger
- Slight degradation of quality
- less expensive than optical zoom
Lighting
Many document cameras are equipped with lights that allow you to brighten
the subject and dispel shadows. The type of lighting you need will depend on
the room in which you plan on doing your presentation. In a bright, well-lit
room, lighting may not be needed; however, in a dark room or room with uneven
lighting sidelights can be used. A special type of light is a backlight, which
allows you to use transparencies, X-rays or slides.
Image Storage
A growing number of document cameras / visual
presenters allow you to actually
capture and store images for later use. Some more elaborate presenters use memory
cards for storage but most utilize internal memory that can later be downloaded
into a computer.
Camcor Links
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