Why You Should be Shooting Raw
Your camera most likely has a choice of image formats for storing the pictures on the memory card. JPEG is probably the format that is most familiar to anyone who has been using a digital camera.
There is nothing wrong with JPEG if you are taking casual shots. JPEG files are ready to use right out of the camera. Why go through the process of adjusting raw images of the kids opening presents when you are just going to email them to Grandma? And JPEG is just fine for journalists and sports photographers who are shooting nine frames a second and who need small images to transmit across the wire. So what is wrong with JPEG? Absolutely nothing—unless you care about having complete creative control over all of your image data (as opposed to what a compression algorithm thinks is important).
Just to give you a little background, JPEG is not actually an image format. It is a compression standard, and compression is where things can go bad. When you have your camera set to JPEG—whether it is set to High or Low compression—you are telling the camera to process the image however it sees fit and then throw away enough image data to make it shrink into a smaller space. In doing so, you give up subtle image details that you will never get back in postprocessing. That is an awfully simplified statement, but it’s still fairly accurate.
So why raw?
First and foremost, raw images are not compressed. (Some cameras have a compressed raw format, but it is lossless compression, which means there is no loss of actual image data.) Also, raw image files will require you to perform postprocessing on your photographs. This is not only necessary, it is the reason that most photographers use the raw format.
Raw images have a greater dynamic range than JPEG-processed images. This means that you can recover image detail in the highlights and shadows that just isn’t available in JPEG-processed images.
A raw image is a 14-bit image, which means it contains more color information than a JPEG, which is almost always an 8-bit image. More color information means more to work with and smoother changes between tones—kind of like the difference between performing surgery with a scalpel as opposed to a butcher’s knife. They’ll both get the job done, but one will do less damage.
A raw image offers more control over sharpening, because you are the one who is applying it according to the effect you want to achieve. Once again, JPEG processing applies a standard amount of sharpening that you cannot change after the fact. Once it is done, it’s done.
Finally, and most importantly, a raw file is your digital negative. No matter what you do to it, you won’t change it unless you save your file in a different format. This means that you can come back to that raw file later and try different processing settings to achieve differing results and never harm the original image. By comparison, if you make a change to your JPEG and accidentally save the file, guess what? You have a new original file, and you will never get back to that first image. That alone should make you sit up and take notice.