We photographers and wannabes work hard to create our images, so why would we ever want to throw away significant amounts of data that comprise our photographs? I would argue that, in most circumstances, you wouldn't.
Shooting RAW means that you are maintaining all of the data that was collected when your camera took the shot. Shooting in JPEG format means that the camera has made decisions for you concerning, brightness, contrast, sharpness, etc. and discarded data that was not needed given those decisions. A RAW file (photo) is unprocessed; a JPEG file is processed. That's not to say you can't do some further processing on a JPEG image in whatever software you're using like Aperture, Picasa or Lightroom, because you can, but you can do more with the original RAW file.
But just like an archer, you'll pull the arrow from your quiver that you think will reach your mark, and by that I mean you may not always want to shoot in RAW, sometimes JPEG could reach your mark. I would suggest that you would want to shoot in RAW when:
- You know you want maximum control over the look of your final product.
- You know you want to process the entire image yourself.
- File size doesn't matter, because raw files are significantly larger than JPEG files.
- You are not shooting in continuous or burst mode, capturing several images per second, as raw files fill a camera's multiple-shot buffer faster because they're larger and once the buffer is full, you're done shooting until the images are written to the memory card and you can start again.
- You want to maintain the original file unaltered (the digital RAW negative) in your archives.
I would suggest that you might want to shoot JPEGs, when:
- Space is an issue, either on your memory card or on your computer - JPEGs take up far less space than raw files.
- You don't mind if the camera makes some processing decisions for you concerning, brightness, contrast, sharpness, etc.
- You are shooting fast moving objects like planes, cars, children and the like, in continuous mode as you will get more images per burst shooting JPEGs because of their smaller size.
- You have no need to preserve the original digital negative in its entirety.
There's a place in this world for both types of files and shooting, but if you remain undecided, you can always set the camera to shoot both RAW+JPEG at the same time - just know that that will take up even more precious storage space on your cards and computers. I must admit when I firsted started working in this digital world, I shot RAW+JPEG. It was like an insurance policy. I knew I'd have a finished picture right away (for the immediate gratification person inside me) but I'd also be able to work on the RAW file to learn the art of post-processing. I will say that I didn't do this for very long because it became very confusing. Now I make a decision at the start of the shoot depending on what I will be doing with the images at the end of the day ... or week ...or month ... or year.
Note: By looking at the control panel on your camera (on the top right of this Nikon D90), you will see the number of images that each Image Quality setting will give you, in this case on a 4 gig memory card:
On a RAW Image Quality Setting, this 4 gig chip will hold 261 RAW images.
On a large, Fine JPEG Image Quality setting, this 4 gig chip will hold 534 JPEGs.
On a RAW+Fine Large JPEG Image Quality setting, this 4 gig chip will hold on 175 distinct images.
Check out the J is for JPEG post by clicking here.