Buying a portable or desktop closed-circuit television (CCTV) is a costly venture for most people. Although the prices of various CCTVs are generally comparable, users should be prepared to do their own price and product comparisons before they purchase a CCTV. Costs aside, there are several factors that you should consider before you purchase a CCTV, whether for yourself or if you are assisting another person to purchase one.
First, it is essential to undergo a comprehensive clinical low vision evaluation to determine your visual functioning. During this assessment, the vision specialist (an optometrist, ophthalmologist, or another professional with expertise in visual impairment) can determine how your visual functioning can be enhanced through the use of optical devices (such as hand or stand magnifiers and prescriptive lenses) and nonoptical devices. Some low vision clinics also conduct adaptive technology assessments, including assessments of the use of CCTVs.
Aside from the obvious personal benefits of having your vision thoroughly evaluated, an assessment is also an opportunity to experiment with several low vision devices that may otherwise be unavailable to you. It is important to try out various devices because what appears to be a good product is sometimes not as good as you thought it might be before you tried it. In this "how to" article, you will discover what you need to know to purchase the best CCTV to meet your (or your client's) needs.
Understanding the Eye Condition
It is essential to understand your eye condition. Most users expect to be able to use a device for several years. Therefore, the CCTV that you purchase should be able to meet all your visual needs, whether your vision will worsen over time or remain stable or if secondary complications arise.
- If you have a progressive eye condition, consider a desktop CCTV that is able to magnify up to at least 20X or 30X magnification to meet your need for larger letters as the condition worsens. This magnification should serve your needs until you reach a near visual acuity of approximately 20/600 or greater. However, if extreme magnification is needed, you may wish to consider an alternative reading medium to print, such as braille, speech output, audiotape, or DAISY-formatted reading materials.
- If you are sensitive to light, consider CCTVs that have a dimming feature and a reverse polarity feature (the majority of CCTVs have both these features).
- If you are unable to perceive color, then purchasing a color CCTV is a waste of money because color CCTVs are usually more expensive than are black-and-white CCTVs.
- If you have poor eye muscle function, purchasing a CCTV that can manipulate the text in a way that requires only limited movement of the eyes (such as single-line continuous text movement across or down the center of the screen) would be appropriate.
- If you are extremely sensitive to glare, an LCD (liquid crystal display) panel or monitor will likely have less glare reflecting off it than a monitor that has a glass covering. Also, if the monitor can be angled differently, you can manually manipulate the amount of glare that is reflected off the screen by tilting the monitor. Tube monitors typically cannot be tilted, whereas LCD panels typically can be tilted much more easily.
How and where you plan to use the CCTV will influence the type of CCTV that should be purchased. The majority of persons with low vision use CCTVs for accessing print materials at work or at school and for leisure reading. The general rule of thumb for prolonged reading tasks is to use a desktop CCTV with a large monitor, so you can see several words and lines of print on the monitor at one time. For short-term reading tasks like reading a menu or looking up a telephone number, a portable CCTV is sufficient.
- If you intend to engage in prolonged reading tasks, it is better to buy a desktop CCTV, so more text is visible on the screen at one time. Also, a larger monitor can help reduce eye fatigue and strain by enabling you to focus on several enlarged words at the same time, rather than to read a word letter by letter on a portable CCTV with a much smaller screen.
- If you intend to use one location as a reading-and-writing station, a desktop CCTV is suitable. With a desktop CCTV, you bring reading materials to the CCTV, rather than bring the CCTV to where the reading material is. For example, in schools, students tend to have their desktop CCTVs in a resource room or library--they leave their classes and bring the reading material to the CCTVs to complete their reading tasks. Similarly, adults with low vision who are in the workforce usually keep their desktop CCTVs in their work spaces, closest to where they are required to do most of their reading and writing. At home, many elderly people with low vision keep their CCTVs in the living room, family room, or study because these locations are usually where they engage in leisure reading activities.
- If you need to move from one location to another (at school or in the workplace) to complete reading and writing tasks, then a portable CCTV may be the most suitable in any setting.
- If you want to connect the CCTV camera to a computer (for example, to obtain split-screen viewing of a book or manual while you are working on the computer), the CCTV that you need to purchase must include a video cable that can be connected to your computer system. Not all CCTVs have this capability, and most portable CCTVs do not.
- If you are an elderly person who wants to be able to perform only simple literacy tasks (such as reading an issue of TV Guide or checking labels on medicine bottles), an elaborate CCTV that has lots of control switches and the ability to connect to a computer, for example, may not be necessary. A desktop CCTV that simply enlarges print material is likely to be all that you will need.
- For young children with low vision, a CCTV must be able to stand up to impatient hands. An LCD panel may not be the best monitor for young children because young children tend to want to touch or poke at the monitor. A tube monitor may hold up better than an LCD panel to intentional or unintentional misuse. However, a large-tube CCTV monitor can be dangerous if a child accidentally knocks it off a table or a desk.
Individual Preferences and Differences
All people have preferences for how far away they sit from a monitor, what type of chair they like to sit in, how they position their feet when they are reading or writing, how large the desktop or table is, and what sort of lighting they like to have when reading or writing with a CCTV. These preferences will influence whether they use the CCTV efficiently and comfortably. In some cases, the monitor may be too high or the X-Y table may be too low if users are unwilling or unable to modify their surroundings (by, for example, changing the height of the desk or chair).
- If you prefer a rigid chair or a table that does not adjust in height, the CCTV must be positioned in a way that will enable you to view the monitor comfortably. If your head is tilted upward to see a monitor that is positioned on a desk or table that is too high, neck strain will result. Consequently, a higher chair may be needed to bring your body into better alignment with the monitor. Similarly, if the monitor is too low, neck strain will also occur; in this case, a lower chair may be needed.
- If you sit in a wheelchair, an LCD monitor that is separate from the camera and X-Y table could be placed on the wheelchair's tray table. You can then see the monitor from a reasonable distance while your hand manipulates the X-Y table on a different work surface to the side of the wheelchair. However, good manual dexterity and physical strength are needed for such a system to work effectively. In some cases, another person may have to manipulate the reading material under the camera so you can concentrate on reading what is on the CCTV monitor. A tube monitor is far too large and heavy to be placed on a wheelchair tray.
- For young children whose feet dangle from the chair because of their small stature, it is important to ensure that the table and chair are at the correct height for the placement of a CCTV monitor. Also, providing a footrest or footstool upon which a child can place his or her feet will "ground" the child and give him or her a sense of security in that position. However, most desktop CCTVs are too tall for young users. LCD panels that have a tilting feature can be angled so that small children are better able to see the monitor more comfortably.
- For users who are young, elderly, or cognitively challenged, elaborate CCTVs with lots of buttons and switches can impede their ability to use them independently. Sometimes, simple is better, especially if an individual is used to a certain type of CCTV.
When you use a CCTV for reading, it is important to think about how much reading you will do with the device and the type of reading tasks that you typically undertake. Where the majority of the reading tasks take place is also important because environmental factors, such as lighting conditions, the height of the table and chair, and the availability of space can affect how well the CCTV works for you.
- If you intend to use a CCTV for prolonged reading tasks, it is best to purchase a desktop CCTV. As was mentioned earlier, a large-monitor (tube or LCD panel) desktop CCTV can display more words at one time than can a portable CCTV with a smaller display. Given comfortable seating and a table or desk of a suitable height, you can generally use a CCTV for prolonged reading tasks (such as more than 30 minutes at a time) with minimal visual discomfort. However, using a portable CCTV for prolonged reading tasks will likely result in visual fatigue because typically (depending on the level of magnification) only one or two words are visible on the display at a time, which forces you to work harder to keep focused on the line of print and to maintain your place on the page.
- If you intend to use a CCTV primarily for short reading tasks, a portable CCTV will be sufficient. Many portable CCTVs are now small enough and light enough to fit in a shirt pocket or purse with ease. Filling in forms, reading labels on files, and checking an address in an address book are examples of daily living tasks that can be accomplished by using a portable CCTV. It is important to note that a handheld magnifier can also be used to complete these tasks if the magnifier enlarges print to the necessary size. A magnifier may therefore be a better and cheaper alternative to a portable CCTV. However, they do not have the ability to reverse the polarity of print (such as from black print on white paper to white print on a black background). The ability to reverse the polarity of print may be a feature that users need to read comfortably and efficiently--a portable CCTV can change the foreground and background colors, thereby making it a better choice than a magnifier for some users.
When you purchase a CCTV, it is important to remember your writing needs, as well as your reading needs. Having ample clearance between the camera and the writing surface is important in both portable and desktop CCTVs. If you have the opportunity to test several CCTVs, it is imperative that you try to write under the CCTV. It may turn out that the CCTV in question is great for reading tasks but awful for writing tasks.
- If you intend to write for a prolonged period, a desktop CCTV with ample clearance between the X-Y table and the monitor and/or camera mount is preferable. How the CCTV is positioned is also important, since one component of the task is often sacrificed for the comfort of the other. That is, depending on the type of CCTV being used, if the monitor is placed at eye level, the X-Y table may be too low to write comfortably. If you adjust the height of the table to make writing more comfortable, then the monitor may be too high. Finding a desktop CCTV that includes a height-adjustable monitor will solve this problem.
- If you intend to write for short periods in various locations, a portable CCTV is suitable. However, since many portable CCTVs are not designed to provide clear magnification when writing, you need to try out various models before you purchase one. Given that you must hold the portable CCTV in one hand while writing with the other hand, the task can be difficult if you want to write several lines; for example, the paper may slip, and you may not be able to keep the camera focused on the tip of the pen.
Size and Weight of the CCTV
Many styles of desktop and portable CCTVs are on the market. The introduction of LCD panels has changed the overall look and design of CCTVs because the monitors are much thinner and lighter than the traditional tube monitors. Before you decide which type of CCTV to buy, you need to consider the size and weight of the device. For example, not all apartments, classrooms, and offices have enough room for a 21-inch tube monitor, and not all portable CCTVs are small enough to fit into a purse.
- If the amount of space that is available for a CCTV is limited, consider purchasing a CCTV with an LCD monitor.
- If you anticipate having to move the desktop CCTV from one location to another every so often, consider buying a lightweight CCTV. Again, CCTVs with LCD panels tend to be lighter than those with tube monitors.
- If you need a portable CCTV, make sure that it is light enough to be carried in a purse, backpack, briefcase, or pocket. Although there are many types of portable CCTVs, some are more portable than others.
The Bottom Line
Many factors need to be taken into account when you decide which CCTV to purchase. It is important to understand your or your client's visual functioning and needs, as well as how you or the client intends to use the CCTV. If possible, persons with low vision should try out several CCTVs, both portable and desktop, so they can make informed choices. Weighing the benefits and drawbacks of the devices according to the factors discussed in this article should help them make a wise decision.