All digital cameras save pictures in the Jpeg format - you will notice when saving files onto your computer that the file name always ends in .JPG - but some cameras have the option of saving in a different format, known as RAW (although Nikon call it NEF).
Whether you should store photos in RAW format depends on what you plan to do with them after you have taken then. How important the pictures are may also have a bearing on your decision.
For normal, everyday shooting you will get perfectly good results from shooting JPG. There is also nothing to stop you making exceptionally large prints from Jpeg images. RAW becomes important if you plan to enhance your photos are you have taken then using products such as Adobe Photoshop.
Even if you do not have plans to enhance your photos shooting in RAW may be worthwhile if the photos are of great importance to you. For example if you had taken photos at a wedding. For that type of event you may feel that shooting in RAW gives you extra insurance if something goes wrong.
You can expect all Digital SLRs and Compact System Cameras to be able to store images in RAW, but it is worth double checking before you buy.
So what are the main differences between shooting in RAW and Jpeg?
To produce a JPG file the camera has to process the data that it captures. It analyses all the information and tweaks things like colour tone, contrast, sharpness and saturation in order to produce an end result that it hopes you will be happy with. In doing this it also discards some of the information, only keeping the essential data required to make the picture, and also compresses the data to keep files to a manageable size.
A RAW file is exactly the name suggests - all of the raw data is kept, nothing is discarded and no processing takes place.
More advanced cameras will allow you to shoot both JPG and RAW simultaneously. In other words, when you press the button, it will make two copies of the picture, one in JPG format and the other in RAW format. This can be useful, as the JPG is a 'finished' file that is ready to print out, to attach to an email or upload to Facebook or Flikr, whilst you also have the RAW file as your 'negative' if you want to do any additional processing.
Digital SLR Basics
Digital SLRs and Digital Cameras Key Differences
Digital SLR or Compact System Cameras
Digital SLR Handling
Help for Beginners
Lenses and Accessories
Buying a Camera Lens
Digital SLR Accessories
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Summary of Current Models
Recommended Digital SLRs
Digital SLR Guide Author
This guide was written by Ian Younger
There are a number of advantages in shooting in RAW format. Firstly the file contains far more detail than a JPG file, so it is capable of producing higher quality pictures. Secondly a RAW file has much more latitude for making corrections if there are any problems with your exposure. If the picture is too light or too dark you can adjust it and recover detail that may not have been initially visible. A JPG can be darkened or lightened a little, but this will not reveal any more detail, as the detail just isn't there - but in a RAW file there is so much more detail that can be brought out with careful processing.
A RAW file is sometimes referred to as a 'digital negative', because you can process it in exactly the way you want to get the desired result, rather than simply relying on the camera to process the file for you.
Shooting in RAW gives you much more leeway to correct errors after a picture has been taken.. If you had any settings wrong on the camera you can correct the results in the processing. For example if you were shooting outdoors but had left the white balance set to fluorescent your picture will have a blue colour cast, but when editing a RAW file you can simply re-process it as if the white balance setting on the camera had been set for daylight.
To give an extreme example, let's say you have accidentally left the camera set to shoot in black and white. If you only shoot in JPG you will be stuck with a black and white picture, as all the colour information will have been thrown away in the processing in-camera. If you have shot in RAW, however, all of the data is kept and you can change your mind and re-process the file on your computer to produce a colour picture. Sometimes shooting in RAW can be a form of insurance, giving you the best chance of rescuing something usable when you have made silly mistakes at the picture-taking stage.
Having said all of that, you need to be aware of the downsides of shooting in RAW as well. Firstly, the files are much, much bigger - because all of the information is kept and nothing discarded. You will need to make sure you have a large capacity memory card in your camera, as RAW files will eat up storage space - and if you have set the camera to shoot both RAW and JPG simultaneously then your card will fill up even quicker!
Secondly, RAW is not a universal format. Any software can open a JPG, but you need dedicated software to open and edit your RAW files. The RAW files from a Canon camera are completely different to the RAW files from a Nikon or an Olympus. Not only that but the RAW files from different models from the same manufacturer are different. However, the disk that comes with your camera will usually have some software on it that will allow you to open and edit your RAW files.
If you want a more sophisticated and powerful editing package then you may want to think about investing in something like Adobe Photoshop.