The benefits of RAW.

The Highway 7 bridge between Mission and Abbotsford

Sometimes my images just come out all wrong.  In the above photo, I had unintentionally underexposed the photograph.  The top shot is how the unprocessed raw image.  You can tell by looking at the histogram (top right) that it is underexposed because the graph is pressed up against the left side while the right side has no data at all.  If you look at the slider controls below the histogram, they are all set to "0".  This means no changes have been made to the file.

The lower image is the same as the top one, but the slider controls have been altered.  The histogram now has a nice balance across the whole graph, and no end is empty or has data bars jumping off.  The image is clearly better.  Raw images are very flexible when it comes to altering an exposure.  This is because there is data present which would normally be lost when shooting jpegs.  This isn't to say that you cannot make changes on jpeg files, it is just that you will lose details in shadow and highlight areas which raw files will retain.

This doesn't mean that exposure doesn't matter.  You always want to do the best job you can in making an image.  Each error in making the image affects the final outcome, even if there is a certain amount of latitude.  Noise, fine detail distinction, and contrast are all adversely altered. 

The disadvantages of a raw file over the ubiquitous jpeg are many.  Raw images are larger, require post processing, and often are not readable without the correct software.  Raw files created by newer cameras may not be supported in older software, meaning that you will have to rely on conversion software such as Adobe's DNG Converter to access them.  All these issues pale in comparison though to their benefits.

Raw files give the user much greater control in colour balance, sharpening, and selecting the correct amount of image correction on a picture by picture basis instead of having to alter these values in camera.  There are fewer artifacts due to the lack of compression.  I especially love the greater latitude as mentioned above.

Keep in mind that not all raw files are the same.  I have found that compacts sporting raw capability do not measure up to the image quality produced by larger sensor cameras.  In general, it can be said that larger sensor raw images are superior to similar pictures created by smaller sensor cameras.  This is especially true once you drop below a 2:1 crop factor.