what is Raw support? why is it useful and what does it do?

Question

On Cnet.com they keep saying that certain cameras lack Raw support

Answer 1

Cameras that have RAW support can (also) store files where they retain the exact information from every single pixel. These are huge files, but they can come in handy if you want to make a poster size print, or if you want to do extensive editing.
Cameras normally store the pictures as jpg files. These are compressed - good enough for most stuff, but they don't give you 100% of what the sensor is capable of.
It's kind of like the quality difference of a store bought CD vs. mp3 files. MP3 files are good enough 99% of the time, but not always.

Answer 2

When a camera takes a picture it takes all the information gathered by the sensor and organizes it into a cogent image. The standard format for this a JPEG. This is a lossy format, which means that some info is lost during the compression routine (not alot I might add). However, every time the JPEG is modified and recompressed, more is lost, so it's a lousy format to use if you need to modify images with software. A better format is TIFF (a non lossy format), but the RAW is the best format. This is an actual recording of every bit of info gathered by the sensor with no interpretation or development. Being that, certain algorithms that make a picture have not been run yet (color development, exposure, white balance, sharpness, contrast, digital zoom etc.) Since they haven't been run yet, you can change them AFTER THE FACT. Don't like the result of the intitial settings, use software to change them and see if you get a better result....THEN run the JPEG routine on it to get the actual image without loss. Also, there is alot more info in the RAW file than in the JPEG. If you plan to modify the image in other ways, for example to remove facial blemishes, the image will look alot better if you do it on the RAW image instead of the JPEG.

Answer 3

RAW is definitely the best format to use if you plan to edit your photos later. As mentioned, RAW is the sensor data before some modifications have been applied to produce an image, so you can change these after you take the photo, whereas with jpeg, you’re stuck with them. These include very handy things like white balance, ev compensation, sharpness, saturation. It doesn’t include things like focus, shutter speed, and f-stop. Aside from increased file size, there is no downside to using RAW. Also if you edit settings in RAW, you can save and open and adjust these settings as much as you want without degrading the original data, they are stored separately from the image data in the file. Whereas every time you edit and save a jpeg file, you lose a bit of quality due to actually changing the image data and recompressing it.