If there was such a thing as a photographers' bar (and maybe there is and no one's told me about it yet), I'm sure that one of the most heated topics of happy-hour debate would be the perpetual row over RAW vs. Jpeg camera formats. Other than the fifty-year Canon vs. Nikon holy war, nothing incenses the opposing factions in photo circles like the discussion over which recording format is better. And if you think that I'm going to stick my foot in the middle of that dog fight, well...maybe just a bit.
The truth is, of course, that neither format is inherently superior to the other; it's all a matter of how you work and how involved you are with image editing (and if someone insists that one is intrinsically best, beware that bulging vein in their neck--it's about to start throbbing). It actually took me years to arrive at the decision that RAW was a better format for me and, in professional circles, at least, I was very late to the game. Now, however, I shoot RAW almost exclusively--and I'll tell you why.
First, let me briefly explain the differences. Whenever you take a photograph in the jpeg format, regardless of how you have the camera set up or what mode you're working in, the camera processes your image before you see it, automatically enhancing things like color saturation and sharpness, for example, to make your images look as good as possible right out of the camera. And for a lot of photographers (and photographic situations), that's a good thing. If all that you do is drop your card off at the local CVS to be printed, for instance, this will vastly improve the quality and "prettiness" factor of your images. So what's wrong with that? Nothing.
The price you pay for that quality convenience, however, is that the camera has taken a certain amount of creative control away from you. You can choose to set the white balance to "cloudy day," for instance, to warm up shots on a cloudy day--but you are stuck with that white balance. You are also stuck, to a degree, with the exposure that was set when you shot the photo. Again, in many cases, this isn't that big a problem. A larger problem is that, in order to keep files as small and manageable as possible and to keep your camera cranking out images as quickly as you can press the shutter button, the camera also compresses those images. That's what jpeg is--a compression scenario that shrinks images by tossing out similar pixels before you even seen them. Jpeg, in fact, is known as a lossy format--it loses information during processing.
RAW images, on the other, hand, are recorded with virtually no behind-the-scenes enhancement. The image that comes out of the camera is almost exactly as you shot it. The most common analogy for this, in fact, is that a RAW image is like a camera negative--all of the information is there for you to alter as you like in editing--just as you would interpret a negative in the traditional darkroom. Even more importantly, nothing is lost or left behind in translation. Every pixel that was exposed is maintained and nothing is "compressed," thus RAW is referred to as a lossless format.
Where RAW really gets interesting, and quite useful, is during the pre-editing process. Whenever you download and then open a RAW file you must first go through a "conversion" step that enables you to change some key things like exposure, white balance, tint, contrast and saturation--and on a very detailed level. In terms of exposure, for example, you can be off be several stops in-camera and actually change the exposure during editing. You're not just making a curves or levels adjustment, as you can do with a jpeg file, but you're actually changing the exposure. You can also adjust the white balance in any way you like. If, for example, you weren't sure if you wanted the image to be warm or cool, or if the dominant light source was tungsten or daylight, no problem--you can make that decision after the fact. You can also adjust the hue/saturation/luminosity of each individual color before you even begin to edit the image--quite amazing. And you can pre-adjust curves in the conversion process (though to be honest, I do all of my real curves work in Photsohop after conversion.)
It was largely the ability to change the first two things--exposure and white balance--that won me over. That and the fact that my good friend and one of the world's premiere food photographers, Jon Van Gorder, convinced me that by not tossing away duplicate pixels and by editing in 16-bits instead of 8-bits (another RAW feature), the quality of my images would vastly improve. I tried it for a few weeks and he was right. Once I switched to RAW, my images were radically better. My editing also became more careful, more calculated and I understood more about what I was doing and why.
Are there downsides to shooting RAW? Yes, but for me they are slight. For one, RAW files take up huge amounts of both card space and hard drive space. But memory prices have plummeted so much that that is no longer a concern to me. You can buy a terabyte hard drive now for a few hundred dollars--unimaginable when I started shooting digitally. Also, because the files are so large it slows your shooting down; it simply takes the camera longer to transfer the images from the buffer to your memory card. And finally, there is that extra step in processing that you must go through.
So is RAW better? Ask me in the photographers' bar some night. In the meantime, look at the type of work you do, the level of quality you demand from your images, how much time you want to spend editing and how many memory cards you're willing to own. Don't let anyone tell you you're wrong to shoot jpeg if the balance for you tips in that direction. But if RAW sounds appealing to you, try it. I think once you do, you'll be evangelizing in no time.