So all this talk of RAW. Is it better to take pics in RAW than JPEG ?
Short answer, yes.
Long answer, that depends.
I know at least 1 professional wedding photographer (and this ones actually good, unlike the one sexytw met above) who only shoots JPG. He contends its always better to get the shot right in the camera, and hes good enough that he basically doesnt miss.
I only shoot RAW for a few reasons, some practical, some theoretical (ie because Im a bit of a geek)
1. Data quality. The camera (all current DSLRs as far as I am aware) produces 12bits per channel of colour data with a Bayer pattern colour filter. To create a displayable image, the image must be "de-mosaiced" and reduced to 8bits per channel by the application of a tone curve. There are a number of algorithms for de mosaicing bayer image data, the better ones require more processor time and so tend not to be used in camera. Hence shoot in RAW and process on a nice fast PC (or dont worry about how long the processing takes) and you end up with a better quality result with fewer artifacts in the fine detail. Also you get to pick which 8bits worth of data you keep, which gives you a little latitude to tweek the exposure after the fact.
2. White Balance. This is linked to the tone curve above. With a RAW photograph I can change the white balance 100 times having got it totally wrong to begin with and still have exactly the same data available I started with. With a JPG if its gone blue because you shot under daylight with tungsten ballence set there is little you can do about it, because the necessary red and green channel data has already been thrown away.
3. Flexibility. I CAN tweek a RAW to my hearts content. I have spent hours on one photo before now when I really wanted it to be perfect. Or, I can batch convert using default camera settings and get exactly the same output I would have got from the camera shooting JPG. Or, of course, any level in between.
JPG limits your options, RAW sets you free.
From what Ive read above,
RAWTherapee (my converter of choice for most shots) is to Lightroom as GIMP is to Photoshop. That is, Lightroom certainly has a few useful features which RT lacks, but wheather the difference is worth the price is quite open for debate.
Also worthy of note are
BibbleSilkypixCaptureOneUFRAW