GIF

JPEG is a compressed format, that seeks a balance between image quality to and filesize. Most digital cameras save their images in this format as a default setting. The JPEG image is stored using lossy compression and you can vary the amount of compression. Lossy compression looses data to make the file smaller. This allows you to reduce file size while retaining the quality needed for a display or print medium. Computer displays do not require as much information as a print.

JPG stands for Joint Photographic Group, which is the name of the organization which created this format.

Digital editing programs will let you set the JPG quality:

• If you choose high quality then the JPG file will have all the details of the photograph, but the file size will be large.
• If you choose medium quality you will have a very decent photograph with a reasonable file size.
• If you select low quality then the file size will be small, but the image will appear blurry and blocky.

PNG is an image format that was developed as a replacement for a number of older formats. Like TIFF, it is lossles, and takes less disk space. Your camera is unlikely to support PNG but it can be a great post capture format.

PNG is an extensible file format for the lossless, portable, well-compressed storage of raster images. PNG provides a patent-free replacement for GIF and can also replace many common uses of TIFF. PNG is designed to work well in online viewing applications, such as the World Wide Web, so it is fully streamable with a progressive display option. Also, PNG can store gamma and chromaticity data for improved color matching on heterogeneous platforms. PNG supports 8 and 16 bits / colors /pixels depth. It's the perfect file format to archive your photographs. For more information about the PNG format see the PNG homepage.

TIFF may be stored by the camera in uncompressed form or using lossless compression algorithm (Adobe Deflate). It maintains higher image quality and the storage requirements are larger. Some cameras let you save your images in this format and it is a popular format because of its lossless compression algorithm. The problem is that the format has been altered by so many people that there are now 50 or more flavors and not all are recognizable by programs.

Some, typically more expensive, cameras allow you to store images in RAW format. RAW format is not really an image standard at all. It is different for every make of camera. RAW format images contain all the data that is taken directly from the camera's image sensor before the software in the camera applies things like white balance, sharpening etc.. When you are working with the RAW format you are working with all the information that the camera sensor had to work with. Many photographers will tell you that shooting in raw is more like shooting with film. The RAW format simply offers them maximum flexibility. The downside to this format is the large file size.

To learn more about RAW check out these very hel;pful guides. The Luminous Landscape and Cambridge in Colour.