A video magnifier (also known as a CCTV) is a simple way of reading text, images and maps for people with some useful vision. Printed material and objects are placed under a camera and the magnified image is displayed on a television screen or computer monitor. They are most often used for reading, but some can also be used for writing, checking a price tag, looking at a timetable or to read a whiteboard in a classroom.
Many people find they can read more comfortably with a video magnifier than with a traditional glass magnifier and therefore for longer periods. There is no absolute way of knowing whether a video magnifier will help you without trying one for yourself.
Models either have a fixed or variable level of magnification. Those with a fixed level of magnification tend to be cheaper, however are less adaptable to different print sizes which could limit the range of reading material available to you. For instance, the original print could be too large to fit on the screen after it has been magnified.
Each magnifier uses a camera and that is either black and white or full colour. A black and white camera is also known as monochrome as it will display black, white and shades of grey.
Most portable video magnifiers use a close up camera which is suitable for magnifying objects placed close to the camera. For distant objects such as train timetables, notice boards or a classroom environment then you will need a video magnifier with a distance camera.
Some models have enhanced colour options that can make reading text easier. By reducing the number of colours displayed down to two and removing shades, the contrast between text and background is increased. This makes the letters stand out more so it is easier to see. The most common enhanced colour combinations are black text on white and white text on black (also known as reverse mode). Some models have more colour combinations such as yellow on blue, blue on yellow, yellow text on black and a few even let you choose from a list of both text and background colours. Try experimenting with different colours to find the combination that works best for you.
This feature allows you to freeze the image on screen, similar to taking a photograph and is found on most models of portable video magnifiers. Simply hold the portable video magnifier at arms length, freeze the image then bring the magnifier closer to read, for example, to read price tags in a shop.
Desktop models tend to have a reading table (also known as an X-Y table) on four perpendicular runners which allow the table to move forwards, backwards, left and right. The video camera is mounted above the table with the camera pointing downwards towards the centre of the table. By placing a book on the table, you can move the table around, underneath the camera, and read the enlarged text on the screen. The X-Y table makes following the line of text easier and it is less likely that you will lose your place in the text. When reading a book or large amount of text it is advisable to use an X-Y table.
Types of video magnifiers
Video magnifiers can be split into four categories based on how they work and their intended use.
TV based video magnifiers
These video magnifiers plug into a television and tend to be cheaper than other options as you are only buying the camera. This is of course assuming you already have the television and are prepared for it to be used, at times, for reading. They are usually in the form of a handheld camera, similar in shape to a computer mouse, which rests on the paper and is then moved across a line of text. The magnification range and display options are more limited than with a desktop video magnifier but they do provide a simple and cost effective way of reading. These units are simple to set up and operate and can be easily unplugged and moved to another TV.
RNIB have two models of magnifier which plug into your TV; MonoMouse and the Max. The MonoMouse plugs directly into your TV using a SCART socket and will automatically switch channels to display the magnified image. The MonoMouse is available with either low or high magnification. The actual amount of magnification will depend on the size of your TV but on a 20 inch TV the low will provide 13 times magnification and the high 24 times.
The Max video magnifier can be connected to your TV via SCART or component cable and has a simple dial to enable you to zoom in and out for different text sizes. It also has two enhanced contrast modes; black text on a white background and white text on black. There are a number of different models available with prices starting from £89.00.
Portable video magnifiers
Primarily portable video magnifiers are intended to be used when you are out and about at the shops, travelling, at school, at work or at home. They have an integrated screen with a battery so it can be used for at least a couple of hours. They vary in size but are generally pocket or handbag sized so are easy to carry around. They are most often used for checking price tags, receipts, timetables, notice boards, bills, menus, newspapers and magazines whilst travelling. What makes each of the models different is their physical size, screen size, weight and camera location.
The size of screen can be particularly important, especially with high levels of magnification as the amount of text that can appear on screen will reduce as the magnification increases. Conversely a larger screen size will increase its physical size and then reduces its portability. It is therefore advisable to discover the size of text you can comfortably read and work backwards from there. As a rough indication, if you require text sizes of over 72 point (1.8 cm) it is unlikely that a portable video magnifier will display enough characters on the screen to allow you to read. In this case a TV based or desktop magnifier would be more suitable for reading.
Desktop video magnifiers
As the name suggests this type of video magnifier is intended for use on a desk or work surface. These are dedicated, standalone machines and as such, have the greatest range of features compared to other types of video magnifier. Generally they have a camera in a fixed position some distance above the desktop and printed material is placed on a reading table. This table is on rollers to allow it to be easily moved left to right and backwards and forwards. The image is viewed on an integrated monitor and can be adjusted for contrast, magnification and colour, all to suit you. Desktop magnifiers can offer a magnification range as low as 1.5 times and as high as 60 times, although the range is usually narrower than this.
RNIB and Humanware have joined forces to develop SmartView Synergy, a high quality desktop video magnifier. A number of different options are available for the SmartView Synergy however the basic model has magnification from 2.6 to 57 times magnification and 16 enhanced colour combinations. There is a choice of monitor sizes; 19 inch, 22 inch widescreen or monitor less so you can use one you already own.
The advanced model also has lines, blinds and red dot pointer. A line gives a solid black line horizontally or vertically on the screen which makes following a line or column of text easier. Blinds can be used at the sides or top and bottom of the screen and reduce the amount of text shown on the screen which can make it easier to read by hiding subsequent lines of text. The red dot pointer helps to identify where on a page the camera is focused. This is particularly useful when reading at high levels of magnification. Prices start at £1,195.00 for the basic model with a 19 inch monitor.
Computer based video magnifiers
Some video magnifier systems link to a computer and allow the screen image to be shared between the video magnifier picture and the computer display. These video magnifiers are often referred to as "screen sharing" or "split-screen" video magnifiers.
The Smartview Synergy advanced can be connected to your computer and enable you to switch between magnifier and computer while using one monitor. This reduces the amount of physical space required and enables more comfortable viewing. Prices start at £1095.00 for the advance model without a monitor.