Scanners/Tablets/Cameras

A scanner is a machine that can take an image and scan it, and then put it on a computer to be saved or edited. The average cost of a  drum scanner is about £250-£5000 depending on the size and quality of the scanner you want. The cost of a flatbed scanner is about £40-£100.

A graphics tablet is a thing you can plug into your computer and use, in programmes such as Photoshop, to draw. It comes with a pad and pen, it can draw very detailed pictures and most tablets have a pressure sensitive surface, this means that the harder you press on the pad the thicker and darker the line on the screen. They come in many different sizes from A6 to A2. Prices range from £50-£1500. The difference in quality of graphics tablets it the sensitivity, on a more expensive tablet the sensitivity is a lot higher. Some of the more expensive tablets have screens on them so you can see where you are drawing easier.

Cameras are used to take pictures, most cameras are portable and take quick and easy photos. Some of the cheaper cameras have lower quality and use what is known as digital zoom, this is when the image isn’t actually zoomed in it is just enlarged making the image quality lower. More expensive cameras, like the ones paparazzi use, have optical zoom, this uses glass to  properly zoom in on the thing you are looking at. Digital zoom cameras are about £50-£250, whereas optical zoom cameras are around £500-£2000. The three types of cameras are DSLR, point and shoot, and camera phones. The resolution of a camera is measured in mega pixels. one mega pixel has one million pixels in it.

Lossy/Lossless/Image file types

Lossy compression is when an image file gets rid of some of the information it deems unnecessary  when saved, this makes the size of the image file smaller. This is only useful if you are only saving the file once and not using it again because each time it is resaved it loses more information.

Lossless compression is where the image file stores all of the original information on it, this means that the image quality is high but the file size is large.  This allows you to open and reopen the file without it losing quality.

JPG is used for images of high quality but small file sizes.  It is the most common type of image file around. It is a raster file type so it has high quality. The pros of this file type are that it delivers has resolution images and small file types which makes them good for photos. JPG's use lossy compression so they aren't good for saving and resaving a lot. 

GIF is also used for images and it is a raster file type. This has high resolution and large file sizes. The pros are that it has very high image quality. The cons are the large file sizes and it only uses 256 colours. GIF uses lossy compression. It can also use transparency and animation.

PNG is a raster file type, they are lossless and keep their image quality and they have large file sizes. They are good for photos. PNG also uses transparency.

PSD is used when saving images in Photoshop, these are high quality images but are extremely large file sizes. They are useful as Photoshop is industry standard and is commonly used so most people can use them. These are raster file types. It uses lossless compression. Photoshop files also save layers.

TIF is similar to PSD but the older version it is pretty much worse in every way, lower quality images and larger file sizes. It is a raster file type. It also uses lossless compression.

BMP is a raster file type. They don’t use any type of compression so they have large file sizes. Only used by Microsoft.

AI is a vector image type. This is mainly used by Adobe Illustrator. Which uses lossless compression. This type of image can be magnified thousands of times and never pixelate. They usually have average sized file types.

EPS image file types use lossless compression and is a vector file type.