Also Known As Document Cameras, Image Presenters, Visual Presenter.

A visualiser is simply a digital camera fixed on the end of an arm (Rigid or Flexible); using the controls on the base unit and/or software you can zoom in and out, freeze and capture an image of whatever is positioned under the camera. Visualisers have the ability to connect to other forms of technology, such as projectors, interactive whiteboards, PC / laptops and TVs.

The Camera is mounted 30-50cm directly above a display space to which any item can be placed i.e. Text, images, Artefacts and living things (for demonstration). You can also save images that you have taken or videos that you have recorded and recall them later to show to your audience.

Visualisers have the ability to connect to virtually any projector, interactive whiteboards, PC Monitors or TV (LCD / Plasma) showing any image to your audience, or saving an image to be used or recalled later. This piece of technology helps visually and interactively to bring the message across to your audience and/or in the classroom to your pupils.

The Zoom capability helps show the item or parts of the item in tremendous detail, with the rotation options this can be from multiple angles. Using Microscope Adapters you can enhance the level of zoom capability to microscopic levels, ideal for scientific/medical applications. Using your visualiser, you can display smaller objects or living things. Items such: flowers, leaves, animals (frogs, insects) etc.

This makes visualisers ideal to have in school classrooms and science labs, as this is something that an overhead projector cannot do. You can also position the visualiser to show what the teacher is doing in the classroom (during a science experiment, for example), which means that the whole class are able to see what is happening without having to crowd around a desk.

Visualisers are sometimes referred to as "Document Cameras", as you can use them to show documents which you may have infront of you instead of files on your computer. For example, you may have a newspaper article that you want to show to your audience or even a map that you can display on a big screen for everybody to see.

Visualiser Key Features

Camera Type

CMOS Cameras tend to be better for displaying text. They also have better zoom capabilities, which helps you to view smaller objects. CMOS Cameras are more commonly found in Schools.

CCD Camera has more of the features which you are likely to find in a video camera and is designed to be used when shooting videos. If this is what you are intending to use your visualiser for, this is definetly the type that you will need.

Resolution

The number of pixels used to make up an image if the resolution. For example, 1024 x 768 pixels (XGA) means that the picture is made up of 1024 columns of pixels by 768, which makes up the whole image. The more pixels that you have in your camera means that your images will appear more defined. However, if your display device (Projector etc) displays less pixels, you will be paying for a feature that you cannot fully utilise.

Zoom Options - Optical/Digital

One of the main features people look for when buying a visualiser is the zoom capabilities. This is a great feature to have, allowing you to get up close to objects. There are two types of zoom - optical and digital.

Optical Zoom uses the lens to zoom in, while Digital Zoom enlarges what the lens sees by using a digital process.

So, "which is better?" I hear you asking. Well, Optical Zoom produces a higher quality image, but the lenses are more expensive. Luckily, many visualisers come designed with both optical zoom and digital zoom, but it is true the higher the optical zoom, the better.

Frame Rate - FPS (Frames Per Second)

Frame rate is determined by the number of images taken per second. It is normally referred to as FPS (frames per second). It is generally said that the higher the frame rate, means the smoother the video performance and also better performance. However, it is important to point out that the human eye can only see a maximum of 30fps (frames per second).

Auto Focus

Auto Focus is another key feature to look out for when looking at purchasing a visualiser. Visualisers that comes with auto focus features, means that when you place an object underneath the camera, the visualiser recognises this and automatically focuses in on the object keeping the image sharp, without any manual intervention. However, some of the 'entry level' visualisers do not possess this feature and have to be manually focussed by the user each time an item is displayed. Having Auto Focus, allows you to keep your hands free so you can point out key areas of information or even go and speak to members of your audience or pupils in a classroom.