Almost every professional photographer with a podcast, blog, twitter account, or heartbeat recommends shooting raw. As well they should; there are a number of reasons to do so.
With the common JPEG output, the camera applies adjustments to that raw data for white balance and other attributes, does some compression, and writes the final file. Once done (assuming you didn’t save the raw file separately), you can never go back to the raw data and make different adjustments the way you could if you had access to the raw file. Additionally, since the JPEG is already compressed, any additional edits you make and save are on an already compressed file, and each time you re-save it with the changes, it is typically re-compressed, reducing it’s quality each time.
A raw image file represents the, well, raw data recorded by the sensor with regard to light and color. Any adjustments that the camera is capable of making to an image is done in a preview-only capacity. The raw file still contains the raw data, theoretically uncompressed as in the case of the JPEG image.
These qualities of shooting in raw mode are the same ones that make it a really forgiving format, especially with modern software. What’s the point of ever touching your white balance options on your camera when you shoot raw? Got it wrong? Who cares! So what if your exposure is off a half step or so, you have enough information in the raw file to be able to make that adjustment in post-processing without anyone really noticing. Can you tell the difference between these images below? One was shot properly exposed, one was shot overexposed and one was shot underexposed; the latter two had their exposures adjusted in Lightroom. If there’s nothing I really care about in the highlights or shadows, why bother nailing the exposure in camera?
White balance? Schmite balance. Have you seen the white balance tools in Lightroom? The eye dropper? I can set the white balance in post production faster than I could put out my gray card and do the custom white balance with the camera. Why bother with that, either? I can set crazy white balances in the camera, pull everything in to Lightroom (which shows a preview based on whatever was set in camera, as seen below with the four images on the right of the film strip) and adjust the white balance on one image, and then paste those settings to all the other images. Painless!
Forgot to shoot with the Rule of Thirds in mind? No problem. Just shoot an image with enough real estate and crop it later. Straighten it later. Clone out unwanted objects later. Apply cool, trendy effects later.
These days, anyone with a camera and some software can create some pretty compelling images. Heck, download some presets or buy some plug-ins, and the software can almost run on autopilot. The photographer becomes nothing more than hired help to lug everything around, act as a tripod, and push a few buttons. No degree, advanced photographic knowledge, or free thinking required.
So what differentiates the photographer as an artist from a button pusher?