RAW vs JPEG
if you have a camera capable of recording RAW files and you are still saving only JPEGs, you are missing out on huge potential in your final images.
First I ought to explain what a RAW file is, and why we do not call it a RAW image. It is not an image because the file is not in any recognisable image format. In fact, the RAW file contains data, a set of values if you like. These numbers represent the signal recorded at each and every pixel of your camera's sensor. Put simply, it is unprocessed data. Raw data.
What we do with this raw data is to pass it through a special program called a RAW converter which can interpret the data and produce an image from it. Every camera which can save RAW files will have the manufacturer's raw converter supplied with it, though many people choose to use something like Adobe's "Camera Raw" plug-in for Photoshop instead: it gives great control over the images it produces and it fits seamlessly into the workflow.
So what makes a RAW file so much better than a JPEG image? A long, long time ago when I had my first camera which could save RAW files and relatively few people knew much about them, I compared my JPEG against my image from the RAW file and could see no difference at all. Absolutely none! Fortunately for me, it wasn't too long before I found out that all the benefits came from the conversion process.
For example, if the lighting changes significantly between shots and your camera's white balance setting does not cope perfectly with that, your JPEG image will have a colour imbalance, or cast. When I photographed swim meets there were usually several different kinds of light in the one shot: daylight, fluorescent, tungsten, and probably others! This is an absolute nightmare for white balance, even on an "auto WB" setting. A RAW file, however, can be converted to an image with whatever white balance setting you want. In fact, the same RAW file can be converted as often as you want, and so any number of white balance settings may be used and then combined to form one final image if necessary.
This process of combining more than one version of the same image from multiple RAW conversions is useful for a lot more than just white balance. You can also alter the exposure, contrast, highlights, shadows, saturation, and a load more - and all of that from the original data instead of trying to make corrective adjustments to a JPEG image that's already been "incorrectly" processed. Some photographers like to apply as many adjustments as possible within the RAW conversion, saying this produces better results than doing it later. I've not done any comparative tests but it seems like sound thinking and I can see no harm in following it.
By now you might be asking why we bother recording JPEGs at all. Why do cameras that can save RAW files also let you save JPEGs? It's a good question. There are two drawbacks to using RAW files. First is that they are much larger than JPEGs, and this can present problems for anyone taking a lot of images, especially if they need to be stored for a long time. Second is that the workflow with RAW files is a little more involved, again causing issues for those photographers with huge numbers of images to handle or a limited time in which to do so.
A good example of needing to use JPEGs is from when I was working as part of a team of equestrian photographers. During a day's event we each might take a thousand or more photos, with these periodically collected and taken back to a central location for competitors to view on a touch screen system, and any orders taken on the day prepared and printed there and then. Preparing the prints had to be done quickly. Also, all images taken needed to be kept on disk drives, and these went back over many years. Storage of all that required a lot of external drives, and that was just for JPEGs. Had it been for RAW files, the storage requirements could have been 3 to 5 times more. Raw files were just too much trouble. Of course, we had to make sure our JPEGs were as well exposed and adjusted for white balance as they could be, straight out of the camera. Ultimately, our customers were mostly interested in how good their horses looked going over the fence, but we always strived to give them that along with high quality photography. However, the ultimate quality achievable from RAW files was just not practical to achieve.
Serious amateur photographers and professionals with lower throughput really should not be adversely affected by these downsides of RAW. Anyone looking to produce top quality images should definitely not ignore RAW. The additional work required when dealing in low volumes is minimal, and the benefits are undeniable. I strongly urge you to use RAW if you possibly can.