Over the years, closed-circuit television systems for visually impaired persons (today often referred to as video magnifiers) have been slow to change. The implication was that there were not many ways to design a product that provides basic electronic magnification. But that is no longer the case. Anyone who has attended an exhibit of assistive technology where video magnifiers are on display will tell you that almost every vendor has launched a new model. Some manufacturers—such as Optelec, which was acquired by the Dutch company Tieman in 1997—have introduced a whole new line of video magnifiers.
Although this innovation is undeniably a good thing, the question remains: How good are these new video magnifiers?
This Product Evaluation reviews Optelec's ClearView 700, a video magnifier designed to work with a computer. ClearView 700 uses a color camera and offers the ability to split the display screen for use with both the video magnifier and the computer. It uses autofocus technology, which is relatively new in video magnifiers, but what really sets it apart are the function and location of its controls. In an attempt to improve ergonomics, Optelec placed controls on the x-y table, the moveable tray upon which is placed the material to be viewed.
The ClearView 700 was tested on two computers: an older Gateway (75 MHz) with a Gateway EV700 monitor and a new Dell Optiplex (450 MHz) with a Dell Trinitron monitor and a built-in video card. In addition to observations of resolution and contrast using a black-and-white text document, a color photograph, color pages of a phone book, and a medicine bottle, particular attention was paid to overall usability.
Although the ClearView 700 is undergoing design modifications, and it is likely that the product that will be available when this evaluation is published will be different from the product that was tested, the product is now on the market and consumers deserve to see an evaluation. Because technology changes so rapidly and products are constantly updated, consumers should always check with the manufacturer to find out about new and updated features.
Getting Up and Running
The ClearView 700 is easy to set up. The manual was in draft form at the time of testing, but it was in large print and was clear and easy to follow. To enable the split-screen function, it may be necessary to go into the Windows Control Panel and reset resolution and refresh rate. The ClearView 700 requires a resolution setting of either 640 x 480 or 600 x 800 and a refresh rate of between 60 MHz and 75 MHz. The newer Dell computer tested was set at a higher resolution and had to be reset. If the settings are compatible, a green LED on the base of the ClearView 700 lights up.
Basic Form and Function
The ClearView 700's large, black x-y table is mounted on a base that extends beyond the x-y table at the rear of the unit. A support arm is affixed to the back of the base and rises over the middle of the x-y table. The camera and a light source are recessed within the support arm. At the back of the base in the right corner is a control panel and in the left corner is a pencil holder. The pencil holder is a useful feature that is unique to the ClearView 700. Hand grips on each side of the base are used for lifting the unit.
Two aspects of the ClearView's x-y table are particularly noteworthy: the two front corners of the x-y table are designed to be wrist rests, made of hard rubber, and between the wrist rests is a control panel. Push button controls on the x-y table set brightness, camera mode (black on white, inverse video, or true color), focus, and zoom (magnification range is 5.2x to 52x). In addition, there is a locator button that shines a red LED dot on the x-y table designed to help find the current location on the page.
Below the x-y table is a lever that can be set to four possible positions: locking the x-y table in a stationary position, giving the table full freedom, or limiting it to either side-to-side or back-and-forth movement. To operate the lever control, the user first presses it downward to disengage it.
The ClearView 700 model that was evaluated was designed to be placed next to the computer monitor. It was not designed for in-line viewing, in which the monitor is located on a platform directly above the camera.
Controls at the rear of the unit include four push buttons and two rotary knobs. A mode button is used for toggling between a camera-only mode, a computer-only mode, and a split-screen mode. In the camera-only mode it is possible to use another push button to display vertical or horizontal line markers. In the split-screen mode, this button selects a horizontal or vertical split. There are also two rotary knobs for controlling the split: one controls the position of the split and the other the width of a split-screen window. These knobs are also used for position and width of line markers.
Two additional push buttons are located on the rear control panel. One controls foreground and background color selections. The 11 background-foreground color selections can be reversed by pushing the mode button on the x-y table. The other button on the rear control panel is for toggling between the ClearView camera and an additional external camera, which can be attached to the unit for distance viewing. A foot-pedal is also available as an alternative to the mode button for toggling between the camera, the computer, and the split-screen.
How Good Is It?
The x-y table's wrist rests are well designed for comfort and easy access to frequently used controls. Push button autofocus and zoom control on the x-y table worked extremely well. Pushing an autofocus button is certainly much easier than having to adjust a rotary knob. The position locator is a great idea, but when we tried it, results were disappointing. The red dot locator light was not visible enough.
When using the wrist rests and testing x-y table movement, we encountered an unusual problem. When the x-y table was fully extended, the entire unit had a tendency to tip forward. Optelec notified us that they are redesigning the unit to solve the balance problem and at the same time offer a monitor platform above the camera to provide the option of in-line viewing. In its present design, though, the side-by-side monitor placement eliminates the need for a bulky structure to support the monitor. The ClearView 700 has a very attractive streamlined look, is lightweight yet sturdy, and offers plenty of working space for writing. Although many people may be used to an in-line configuration and may prefer it because it limits head movement, it remains to be seen if the redesign of the unit to solve the balance problem and to offer in-line viewing will change the product's usefulness.
We also had problems operating the lever that controls x-y table movement. It is not possible to press the lever down unless the x-y table is positioned so that it extends over the edge of the table on which it sits. In addition, locking the table in a stationary position takes more force than it should and often caused the entire unit to move.
The controls on the rear panel are probably not set and reset as often as the front controls on the x-y table. Nevertheless, we found it awkward to reach across the x-y table to get at the rear controls. When testing the controls, we encountered an optical problem in the split-screen mode. When we opened a window for a camera view, the image was slightly flattened. This was the case when we viewed a text document in black and white and a color photograph.
Resolution and contrast in black and white were good with two exceptions. When we viewed a text document at lower magnification levels, there was slightly less contrast at the bottom of the document. At higher magnification levels, the black letters had a slight amount of smudginess around them. More significantly, we found that the ClearView was not able to give us a well-contrasted image of a color photograph, even at full brightness. The image was too dark at lower magnification levels and had reflective sparkle at higher magnification. Yet contrast was not a problem when we viewed a multi-colored page in the phone book and a medicine bottle with a colored label and faded black-and-white text.
Summing Up
With its innovative x-y table design that includes wrist rests, x-y table-mounted controls, and push button autofocus technology, Optelec's ClearView 700 is a pleasure to use. There are a few design bugs that need to be worked out, such as weight distribution of the unit and ease of use of the mechanism to control x-y table movement. Also, the locator button to help find the current place in a document is a fine idea, but Optelec needs to improve it to make it more effective. The optical characteristics of the ClearView 700 model we evaluated get a mixed review. The most serious bug is the relatively poor contrast achieved when using the color camera to view a photograph. Priced at $3,295, the ClearView 700 is in the upper range of video magnifiers that offer split-screen computer capability.
Manufacturer's Comments
"As stated by the reviewers, the ClearView 700 as tested was brand new to the market, and the actual unit tested was a preproduction model. As such, the manufacturer was and is aware of some bugs and has taken the necessary actions to address the major concerns. One of the most significant improvements has been to increase the brightness of the image. Also, a monitor stand designed to the ergonomic curves of the base units is now supplied as part of the unit. This enables the user to have the monitor 'in-line' (which adds stability to the unit) or to have the monitor and unit side by side. The table lock has been redesigned and now has an effortless three-position locking mechanism. Although the manufacturer understands that some people may find the rear controls somewhat awkward, these controls are normally set once or twice during operation.
"Also, a foot pedal is provided at no additional charge, enabling the user to toggle between screens without having to reach to the rear controls."
Product Information
Product: ClearView 700.
Manufacturer: Optelec U.S.; 6 Liberty Way, Westford, MA 01886; phone: 800-828-1056; fax: 978-692-6073; web site: <www.optelec.com>. Price: $3,295 (monitor not included).
