BACKGROUND ON RAW:
If you're not familiar with ViewNX, it's Nikon's utility for processing .NEF raw camera files. When the camera saves a photo in JPEG, what it does is use the raw data, apply processing to it (e.g. saturation, white balance, etc. etc.), then compress it. Photos saved in raw format contain the unprocessed image information from the camera, with little or no compression. Note: There is no single raw format for cameras (although Adobe made a format called digital negative .DNG which can be used as a raw format, and indeed is used as such by some cameras such as Pentax). Each camera maker has its own raw format.
By saving the photo in a format before processing and with only little or no compression, using raw allows greater flexibility in adjusting the photo (especially white balance and exposure) while preserving the image quality as much as possible. It's like the childhood game of "Pass the Message." If you needed to change the original message, would you rather work from the original message directly, or one of the later messages that is a version of the original message? This isn't only a theoretical advantage. If you do any significant changes to white balance or exposure during postprocessing, the result will look a lot better with raw than with JPEG.
The main disadvantage of using raw is that files are much larger, and processing them takes a much longer time.
Because raw photos have no processing, the software we use to process them can have an impact on the results we get. Some raw processors are simply better than others in terms of color, noise, etc. I like ViewNX for Nikon NEF raw files because the image looks the same as what I see on the preview screen, and the images look punchier. When I process the same raw files in Picasa, for example, the image looks bland. (Adobe Lightroom 3.2 looks pretty good too, though there are a few differences compared to the ViewNX output. I'm still checking it out.)
HIGHLIGHTS OF IMPROVEMENTS OVER VIEWNX:
- Simple movie editor.
- Improved editing. Now includes a crop function (finally!), a straightening function, auto red-eye, auto lateral color aberration correction.
- Improved interface.
- GPS and geotagging support.
Fortunately, ViewNX2 is still free to download.