The Case for Cameras
No enthusiasm for document or PTZ cameras? Maybe you’ve been looking
at the wrong angles.
When discussing the technology needs of a classroom, be careful about mentioning
the word “camera”—it always requires further qualification.
To non-technical people, “camera” can mean any type of electronic
device that isn’t a computer, and which resides in a classroom. But here
are some thoughts on two specific types of legitimate cameras increasingly found
in today’s classrooms:
The concept is simple: This is a camera that looks down at whatever you put
under it; the video image is then sent to a monitor, codec, and/or projector
for viewing by a larger group. Sounds like a godsend, right? Yet, educational
users are mixed on their assessment of the usefulness of document cameras. Some
point to the prevalence of computer-based presentations and cite low actual
usage of existing document cameras to justify not placing them in new or renovated
classrooms. But others like the flexibility of being able to display nearly
anything to students both local and remote, and the ability to replace the venerable
overhead projector as a convenient tool for annotation and real-time, pen-based
interaction. These are the folks who want document cameras in every room.
Two categories. All current document cameras fall into one of two general categories:
those with low resolution output (composite and/or S-video) and those with high-resolution
output (1024x768 or higher). Many negative feelings people have about the use
of document cameras stem from the use of low-resolution devices, which often
deliver fuzzy, incomprehensible text when viewed on a large screen or through
When evaluating document cameras, here’s what you should be considering:
Resolution. Ideally, document camera resolution should
match the native resolution of your other display device(s). Having an SXGA
(1280x1024) signal going to your XGA (1024x768) projector is no better than
having an XGA signal from the document camera. Unless an application is video-only—with
no high resolution display anywhere in the system (and unlikely to ever be added)—I
normally recommend some type of high-resolution document camera over the low-resolution
types. The cost difference is not very much, and the difference in image quality
is immediately apparent.
Refresh rate. Not especially important when looking
at static images (such as a document), refresh rate is very important if the
instructor will be annotating on the page (as in the overhead projector replacement
scenario). The specified frame rate refers to the number of times per second
the screen is updated. Units with a low rate (less than 20 fps) will prove unsatisfactory
for instructors who like to annotate or frequently move the object underneath
the camera. For this style of document camera usage, a refresh rate of 20 fps
or greater is desirable, and 30 fps is considered ideal.
Zoom lens. Often touted as an upsell by manufacturers,
this specification matters much less than you may initially assume. If the instructor
needs to zoom in on small details of a document or a 3D object, then the greater
the zoom ratio, the better. But if the camera is being used primarily to present
text or graphics in the context of a full-size page, then the zoom ratio is
Form factor. Document cameras come in all shapes,
sizes, and mounting locations—from the portable and the full-size, to
the ceiling-mounted. Three ceiling-mounted options are especially worthy of
mention: The Wolfvision (www.wolfvision.com)
VZ-C12 ($12,960 MSRP) has a 16x optical zoom, lens and projects a light field
onto the flat surface below, both to provide added illumination for the subject
and to indicate to the user the extent of the zoom (the light is synchronized
with the zoom lens). The Elmo (www.elmousa.com)
HV-C1000XG ($9,995 MSRP) has a 12x optical zoom lens and a downward-shining
light, but the light is not controlled or synced to the lens, which can create
glare issues at a podium. The Vaddio (www.vaddio.com)
CeilingVIEW Mega-Pro Visualizer ($6,995 MSRP) d'es not offer a supplemental
light, but d'es have a trigger-able laser dot for aiming its 12x optical zoom
lens, based on a native 16:9 3-CCD Sony camera. Plenum above-ceiling housings
for a clean installed look (one of the main reasons for using ceiling-mounted
document cameras in fixed installations) are available from Display Devices
for the WolfVision camera, and from Elmo for its own camera, and the Vaddio
camera comes in its own plenum-rated back-can.
Refresh rate is a very important consideration, if the instructor will be annotating
on the page.
Price. WolfVision is known as the most expensive
brand, with some models above $20,000. But do your homework: Full-size models
VZ-8plus and VZ-8light are surprisingly affordable for many applications. Elmo
and Samsung Techwin (www.samsungtechwin.com)
offer high-performance products with mid-range prices, and several manufacturers
(such as Lumens; www.mylumens.com)
offer products at the low end of the price spectrum. One caveat when considering
document cameras at the budget end of the scale: Features found on more expensive
models are often left off, so if you are buying a document camera for $1,500
expecting to find a video output in addition to the XGA output, be sure to check
the specification sheet first.
Small, pan/tilt/zoom (PTZ) cameras offer a high-performance and low-cost alternative
to using security cameras (CCTV) and broadcast-quality camera systems in classroom
distance-learning, recording, and streaming applications. While new models have
largely replaced the old standbys—Sony (bssc.sel.sony.com)
EVI-D30 and Canon (www.canonusa.com)
VCC3 have improved incrementally in terms of lens zoom and other specs—the real
story is found in control over the cameras.
The new standard PTZ cameras include Sony’s EVI-D70 (18x maximum zoom
vs. 12x for the EVI-D30), EVI-D100 (65-degree maximum horizontal field of view
vs. 48 degrees for the EVI-D30), and BRC-300 (3-CCD instead of 1-CCD and various
options for connectivity including fiber with remote CCU); Canon’s VC-C50i
(26x optical zoom); and Elmo’s PTC-100S (22x optical zoom).
Options. Some options for controlling non-IP cameras:
- Sony offers the RM-BR300 joystick controller ($1,500 MSRP), which can control
up to seven cameras, each with up to 16 presets available.
- Telemetrics (www.telemetricsinc.com)
makes control panels for each of the standard PTZ camera models, including
for Sony, Canon, and Elmo. The CP-ITV series ($1,175 MSRP) controls up to
four cameras with four recallable presets per camera.
- Vaddio’s ProductionVIEW ($4,995 MSRP) controls up to six cameras
with up to 12 presets per camera, but also has a 7x2 switch and built-in LCD
preview for doing (cuts-only) production switching. All sources are synced
internally to prevent glitches.
Vaddio’s new TrackVIEW system will, at least on paper, track an instructor
automatically as he moves around in the front of a room, without relying on
him to hit preset buttons or touch switches or sensors built into the environment.
TrackVIEW uses a dual camera arrangement: one for watching the front of a classroom,
the other for following the instructor. The price for a TrackVIEW package varies
depending on the tracking camera; all systems use a Sony EVI-D70 as the reference
camera, but packages range from $7,495 MSRP for the Sony EVI-D100 as the tracking
camera, to $12,995 MSRP with the Sony BRC-300 camera as the tracking camera.
Once I’ve seen it in action, I’ll let you know how well theory has