Choosing a Digital Format
When starting out in digital photography (and indeed, in many cases for those who have extensive experience in the field), the vast array of terms and acronyms can be bewildering. This is particularly the case for those who are in the market for their first digital camera, but who wish to skip over the lower-end consumer models. If you are in this situation then you may well be confused by manufacturers’ spiel and the ’easy-to-understand’ guides offered for first-time buyers.
File FormatsOne of the most frequently encountered set of acronyms is that which describes the file format in which digital images are stored. Many manufacturers have begun stressing the variety of file types available on some of their pro-sumer models, but what do these terms actually mean? Essentially, a file format is a standard way in which information is encoded for reading by other devices, such as a computer. There are a variety of different file formats for many applications (for example, your word processor will almost certainly be able to save files in multiple formats), and this is also the case in digital imaging.
The most common digital format is JPG, also sometimes referred to as JPEG. This stands for Joint Photographic Experts Group, the committee which established the standard. Today, almost every digital camera on the market will save images in JPG format as standard, and you will find it difficult to find manipulation software that does not recognise this standard.
Raw and JPGWhen you take a photograph with a digital camera, the information received by the sensor is translated into digital code, the format of which is unique to each model of camera (or at least to each manufacturer). This information is known as ‘raw’ data; that is, it has been unprocessed, and is not yet an image - rather, it is still simply a collection of noughts and ones arranged in a proprietary format. When you choose to have your camera save files as JPGs, it will process the raw data in such a way that it then complies with the JPG standard and can be read by other devices that understand this standard. This makes it an excellent way of ensuring compatibility. Similarly, during the processing of the data, the camera will compress the raw information, making the file smaller. This in turn means that you can fit a far larger number of images onto whatever storage medium you are using.
Some photographers, however, still prefer to keep their images in raw format. There are multiple reasons for this, but the most commonly cited is image quality. Photographers who require images of the very highest quality often suggest that the methods by which cameras translate raw data into JPG form is not good enough to produce the best possible results. Instead, they keep the images as they are and process them themselves using dedicated software. This also allows for greater freedom in the editing of images, although this extra freedom is only required by those who wish to perform very advanced tasks.
If you are shooting a large number of images then JPG is the only viable answer - keeping your images in raw format would result in the filling of your memory cards incredibly quickly. Similarly, the extra potential quality offered by the raw format is only available to those with expert knowledge of processing - and, indeed, is only of any relevance to those who are using images for highly specialized purposes.