Visual Presenters Selection and Manufacturer List

Over the past few years visual presenters have been surfacing in university electronic classrooms, corporate conference rooms, and courtrooms. Many models are available from several manufacturers, and appropriate selection requires basic knowledge of how a visual presenter system functions.

What is a visual presenter? The visual presenter (also known as video presenter, visualizer, video imager and by several other names) is a video camera mounted on a stand, which is very close in appearance to a photographic copy stand. Operating on a similar principle as its predecessor, the opaque projector, the visual presenter displays two dimensional objects such as photographs, documents and graphs. Unlike the old opaque projectors, the presenter can also image parts of three-dimensional objects that could include: a page from a book, a machine component, or a murder weapon.

How do visual presenters work? Manufacturers equip most presenters with a single chip video camera mounted on a folding arm and attached to a rectangular base. Usually the base has a control panel and two folding light arms extended up over the projection area. The camera transfers the video image of materials or objects, that the user positions on the base, to a video monitor or projector.

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What are the important features of a visual presenter? Most manufacturers build models with the following features: liner NTSC video output, S-video output, power zoom, a camera lens of at least 8x magnification and a control panel at the front of the base. Manufacturers make most presenters with over head lights, and the majority of models come with built in or attachable base light for transparencies. Manufacturers determine unit cost by camera capability giving specific attention to the size of the camera's CCD (Charged Coupler Device) Chip and lens magnification range. They also build in other features that may drive up the cost included are: audio video mixers, negative to positive conversion controls, and RS-232 terminal controls for IBM platform microcomputers. These enhancements are useful, however, perspective buyers should consider the necessity of such features in their respective environments.

If a school, company or organization has determined that they need a visual presenter, buyers should then devise a basic evaluation criterion. The following criterion of basic requirements is a good starting point:

• Resolution. The CCD chip images the light coming into the camera through the lens, and also helps convert the light into electronic video information. CCD chip sizes are half an inch and a third of an inch; the larger chips collect more light resulting in better resolution. The number of picture elements or pixels measures chip resolution, a chip listed with more than 400,000 pixels will yield a high quality picture. Another resolution measurement is the horizontal lines count, any system that lists a signal output of 400 lines or more will also yield a quality picture.

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• S-video offers the user higher resolution and should be considered for maximum performance. Most presenters come with s-video, however, buyers should not overlook this useful feature during selection.

• Resolution issues. Because of the limitations of NTSC video, photographic sharp resolution is not possible in many presenters. For example most presenters can not project a full eight and a half by eleven page of twelve point characters. In such cases, a user would have to zoom into half the page length to accomplish suitable viewing. The second cavity, which holds true with any video system, is that the resolution of your presenter is only as good as the resolution of the accompanying display unit. If for example, a visual presenter sends out a signal of 450 lines to a projector that only handles 380 lines, the projected resolution will be under the capability of the presenter.

• Zoom Lens and Magnification. Zoom lenses are available in maximum magnifications of 8X, 10X and 12X. Any increase in magnification directly correlates to an increase in price of a visual presenter and an 8X lens will usually suffice for most situations. The 10X and 12X are great for projecting small objects or parts of objects in detail.

• Lighting. Lighting is important because video and darkness have never been compatible partners. The more light that is cast on and reflected from an object the stronger the video signal and the sharper the image. Selection of a presenter with at least two six-watt lights will help enhance the projected image, especially under minimal lighting conditions. A base light is also an important feature if a user is planning to switch projection mode to conventional transparencies or zoom in on 35mm slides. Avoid models with attachable base lights that may be too cumbersome for users to put in place during a lecture.

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• Target, shoot or projection area. This refers to the area of the base that is within the camera view field. The wider the area the more flexibility a user will have in fitting larger objects on the base for projection.

• Rotation of the camera head is a feature that will allow the presenter more flexibility in showing various parts of materials. This avoids the need for excessive shifting of materials.

MANUFACTURERS:
This following is a current list of visual presenter manufacturers. In using this list, readers should note that companies discontinue lines and change model numbers regularly.

Canon
http://www.usa.canon.com/visualcomm/re350/index.html
Canon manufactures the RE-350 Video Visualizer

Eiki
http://www.eiki.ca/usahome.htm
Eiki manufactures the V-4100 Portable Videohead System

Elmo
http://www.elmo-corp.com/elmoei.html (under construction with details on some units available).
Elmo manufactures five Visual Presenters: EV-700AF (a high end three CCD chip system),EV500AF, EV400AF (mid-range model), EV-386 (the inexpensive model with optional accessories), DT100AF Desktop Presenter (the portable on the road model).

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JVC
http://www.jvcpro.com/p20.htm
JVC manufactures the AV-P20U Visual Presenter.

Panasonic
http://www.panasonic.com/MIVC/index.html (use the Panasonic search engine)
Panasonic manufactures the WE-160 Video Imager Copy-Stand Display System.

Samsung
Contact: Samsung Electronics America Inc, at (201) 902-0347 http://www.sosimple.com
Samsung manufactures the SVP4100 and the SVP4200 Video Presenter

Sony
http://www.sel.sony.com/SEL/bppg/videopres/vidpres.html
Sony manufactures two systems: VID-P300 3-CCD Video Presentation Stand (high-end three chip system), and the VID-P1000 Video Presentation Stand.

This article is copyright (c) Terrence McCormack. All Rights Reserved. All commercial use requires the permission of the author and the editors of this journal.

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