A Visualiser is basically a camera that  has the ability to connect to virtually any interactive LED screen, projector, interactive whiteboard, PC monitor or televison to provide a striking visual element to teaching and learning, presentations and much, much more.

Simply put it allows a non-digital item to be displayed digitally.

A Visualiser captures images of text, 3D objects, transparencies and microscope slides and just about anything else you can think of.

Instantly, you can show images to your audience, or record and save images to be used or recalled later.

Visualisers are often called ‘document cameras’ as you can place documents such as A4 printed handouts, papers, magazines or maps underneath them, so that they are displayed on screen.

Overhead projectors, in a far more basic way, can achieve a similar result with text although require you to print or photocopy onto acetate (clear plastic) sheets first.

Visualisers can also display small objects such as insects, flowers, leaves, coins and watches, which overhead projectors cannot do.

You can even position a Visualiser to pick up images to show a Teacher carrying out an experiment that the whole class can see without crowding around a desk.

Visualisers can be used in 3 ways:

1. Camera only
2. With Visualiser Manufacturers Software
3. With third party software such as Interactive Whiteboard Software

 

Important features of a Visualiser

The following are important points to consider when selecting a Visualiser

Camera Type

CMOS or CCD?

CMOS Cameras are best for displaying text and allow better zoom to allow you to view smaller objects.

Most Schools tend to buy CMOS Cameras

A CCD camera is basically a Video camera so if you mainly intend to show Video this is the one you should choose

Camera Quality/Resolution/Number of Pixels

The resolution is the number of pixels that make up an image – e.g.1024 x 768 pixels means the picture is made of 1024 columns of pixels by 768 giving  a total of 786.432 pixels which make up the whole image.

The more pixels in your camera, the more defined your image will appear however the display device (Projector etc) may only be able to display less pixels so unless you plan to change it you can pay for a feature you cant fully utilise

Optical/Digital Zoom

Zoom is a great feature for getting close up with objects and text

The optical zoom use the lens to zoom in while the digital zoom uses a digital process to enlarge what the lens sees.

Optical zoom gives a higher quality image and high optical zoom lenses are more

Many Visualisers offer both optical and digital zoom  but the higher the Optical Zoom the better

Zoom power is expressed in the format ‘6x’ for example which means it can magnify the image by a ratio of 6.

Frame rate (FPS)

The frame rate is the number of images taken per second(often expressed as FPS).

The higher the frame rate the smoother the video performance  and the less ‘jerky’ the image looks.

The higher the frame rate the better the performance.

A word of caution! In our experience some manufacturers list the maximum fps a Visualiser can achieve whereas we state the median performance.

We have found some models with a lower stated FPS outperforming a higher stated FPS (hence the reason we suggest a demonstration!)

Ease of use

Entry level Visualisers have to be manually focussed by the user each time an item needs to be displayed

There’s nothing more annoying than trying to find the right focus.

Look for a Visualiser with Auto Focus and ensure your hands are kept free whilst teaching or presenting.

Visualiser with auto focus features ensures that the object being viewed is automatically in focus and remains sharp without needing any adjustment.

Manual focus can still be used to focus on objects out of the normal work area.

Connectivity

Most Visualisers feature a VGA connection to connect to a projector, a Composite video connection to connect to a TV (LCD / Plasma)  or monitor and a USB connection to communicate with a computer and/or interactive whiteboard.

Some entry level models only connect via USB and a separate splitter may be needed to allow switching between the camera and PC

Some models will offer DVI or HDMI connections for high definition pictures or network and RS232 connection for control.

It is important to ensure when choosing a Visualiser that it has the connections required for your application.

Other Features to consider

Image Freeze

This feature allows the presenter to freeze the image under the Visualiser and remove or change the object under the camera without the image being displayed on the display (Projector,TV etc) changing.

This can be useful when teaching to maintain pupil focus and attention.

Split Screen

A useful feature that a freezes one side of the screen allowing side by side comparisons to be made using the live side

Mirror

This feature gives a mirror image of an item under the Visualiser and allows discussion around reflection

Negative/Positive

A useful feature to show images as negative particularly in Art lessons