Here’s an excellent overview on the three main formats (.jpg, .tif, .raw) for saving digital photos on your camera and some of the pros and cons of each from one my favorite digital photography blogs, EarthBound Light. I know I’ve kicked around the the JPEG vs. RAW format encoding debate with photographer friends plenty of times since I’ve started shooting digital photos and this a great tutorial and overview on the basics for anyone getting more serious about digital imaging.
JPEG – Joint Photographic Experts Group
“With JPEG, the camera applies all the settings you have chosen including sharpening, exposure, white balance, color space and so on. All JPEG images are 8-bits per channel. If you do a good job taking the picture and get it right in camera, all is well, just as it is would be on film. There are better choices though if you want to maximize the potential of your images post-capture.
One nice thing about JPEGs though is that they are all but universal in terms of support. You can take the images straight from the camera and use them in a wide variety of applications. Although smaller than other image formats, even jpegs generally have to be downsized some to send by email. A typical JPEG from the Nikon D100 will be between one and three megabytes in size.”
TIFF – Tagged Image File Format
“TIFF is a very portable format as it is supported by a wide variety of photographic and publishing applications. It makes a poor choice for in camera use though. An image captured as a TIFF is much larger than the same image captured as JPEG, but will only marginal added benefit.
If you want to maximize storage capacity or throughput, stick with JPEG. D100 TIFF files are over 17 megabytes each. If you want to go for maximum potential for quality, read on to find out about RAW.”
RAW – The RAW image format is the data as it comes directly off the CCD, with no in-camera processing is performed.
“The raw data is called “raw” since it is totally unprocessed. At this point, white balance and other adjustments have not been made and the data is still an exact recording of what each photosite recorded. One photosite makes one pixel. Enough pixels and you have a raw image. It won’t look like much until it gets processed into a visible image, a process that happens whenever you open a raw file in Photoshop Adobe Camera Raw, Nikon Capture or other raw file converter.
Raw files contain the absolute maximum amount of data possible, giving you tremendous power to post-process them to maximize your creative efforts. Nikon RAW files (also known as NEF, or “Nikon Electronic Format” files) are 12-bits per channel, as are the raw files created by many other current digital cameras. This makes them ideal to archive as “digital negatives” but does mean that you have to process every file at least to some extent before it can be used as an actual image. NEF files shot on the D100 are right around 10 megabytes each.”