Camera's

There are different type of camera's including camera phones, compact camera's and DSLR's. A camera phone cost's from £20 to £600 and is used by mainly friends taking quick snaps of each other or someone needing to take a quick picture at an unexpected moment. These are generally quick and easy to use and carry around however the quality is generally not very good due to it using a digital lens zoom. This is poor quality because this is where the camera uses software to zoom instead of optical zoom where the camera uses the glass to zoom like binoculars. The compact camera cost's from £50 to £300. They are quick and easy to use and carry around and are lot better quality than camera phones. Allthough they are better quality than camera phones they are not as good as DSLR's. They use optical and digital zoom and typically are 10 megapixels plus. The DSLR is the best cameras you can get, they range from £300 to £5000. Then a further price of around £5000 is needed to buy a lense which is sold seperatly from the camera. These are generally used by proffesional photographers who need to get picture's with details in quick times e.g. the press. These are very high quality however they are very expensive and are a lot bigger than other camera's, and not very easy to carry around. They use optical zoom and are generally 20 megapixels plus and are very high quality. These are the best camera's.

Scanners

This transfers what ever you put on the scanner onto the computer as an image. There are different types of scanners including flatbed scanners, negative scanners, hand scanners and drum scanners. The flatbed scanner is generally used for home use and is usually combined with a printer and ranges from £30 to £300. The disadvantage of this scanner is that it can only scan A4 pieces of paper at most. A hand scanner is small and handheld and scans as you move it over the paper. It is generally poor quality and costs £20 plus. A negative scanner is used to scan negatives and costs around £100 and up. A drum scanner stands up tall and is high quality, it costs from £5000 to £10000. Generally the more money you spend on a scanner the better quality and the higher dpi it is.

Graphics Tablets

These plug into your computer through a usb connection. It is basically a screen which you can control with a pen and draw on and it is sent to the copmputer and the image you are drawing will show up on the screen as you are drawing it. There are many types of tablets ranging from around £50 to £3000. They are all different sizes and usually bigger is better. Some tablets it is possible for what you are drawing to appear on the tablet screen as well as the computer screen so you can see what your drawing like your drawing on paper. These are the best tablets and start at around £1200. Tablets have different levels of sensitivty, for instance some you may have to push the pen really hard to and others you may just have to hover the pen over the tablet.

           
   

File Types

JPG- This is used when dealing with image file types. It is most common image format for camera's, and is mostly used for websites or within e-mail messages as the files are so small. They are not very good for printing and cannot be resized or changed without loosing a lot of quality, however most programmes are able to display, use and save this file type.

GIF- This is similar to jpg and is used when dealing with image file types. This is also a raster file. They are highly compressed files, which unfortunatly means they shudn't be used for graphics with gradients such as photo's.

PNG- This is mostly used to store graphics for web images and the final distribution of images as the files arn't compressed as much as jpg's. This is also a raster file. This supports true colour which is 16 million colours, a real qadvantage. Unfortunatly some programmes to do not run this file correctly and tend to save and print darker than they should.

PSD- This was created by and is used in Adobe Photoshop. This is a vector file and is great for use of Adobe programmes although not many other programmes recognize it.

TIF- This is an image file type, and is a raster file. When you save this file there is no loss of quality. A disadvantage is that the files tend to be very large. The smallest file is still to large to send as an e-mail.

BMP- This is an image file format used to store bitmap digital images. This is a raster file This works well with windows programmes, however is uncampatable with other platforms.

AI- This is an Adobe illustrator file which is a graphics design programme. This is a vector file. A ai file is usaully an original file so you know it was originally used for developing your design. This cannot be brought into other applications unfortunatly.

EPS- This can contain both vector and bitmap data. If the file only contains vector data it can easily be enlarged or reduced without loss of quality.

What is Lossless Compression?

Lossless compression is where all original data in the file remains there after the file is un-compressed. This is generally used for text or speadsheet files as losing bits of information would be a problem.

What is lossy compression?

Lossy compression reduces a file by perminately removing certain infrmation. Usually redundant information. When the file is uncompressed only some of the information will be there however the user may not notice as redundant information was took away. This is generally used for sound and video files as a loss of information will not be noticed by most users.

What is resoloution?

This refers to how much detail the image holds, they are measured in dpi (dots per inch) or ppi. 320 dpi for printing, or 72-100dpi for on screen.