Saved by RAW...

Or... How not to BLOW IT!  And if you do, how to make sure you can recover....

There is constant chatter about which file format should be used when creating digital images..  Jpeg?  RAW?  TIFF?  Which is better and why?

Well... it depends.

Few people capture directly to TIFF, so let's leave that out for now.  By far the most common choice is jpeg.  It's easy to share, has very small file sizes and in general requires less work from camera to computer to output (print, web or computer display).  Jpeg's are the result of the camera's automatic processing of the raw data captured by the camera sensor.  A lot of highlight and shadow information the captured by sensor is discarded during this processing as camera's cpu deems it unimportant to the image.  This brings us to the jpegs biggest drawback..  If you want to use some of the information in post production to bring up detail in the shadows or highlights, you can't.. it's on the cutting room floor.

So you need to be dead on with exposure and white balance because there is very little room to work with a jpeg image in post processing.

On the other hand, the RAW file format is, as it's name would lead you to believe, the raw data the camera's sensor has captured....all of it, nothing is discarded.  This leaves a genrous amount lattitude in post processing techniques to utilize the additional information for creative reasons, like High Dynamic Range processing, Double RAW processing or just extending the dynamic range in the image.  Or, to save your butt when you screw up!

As an example..  I live on the Great South Bay.  I see lots of Sea Gulls, plenty of sparrows, an occasional Osprey or Egret but rarely an in-land bird of prey...  So when I spotted a Sharp Shinned Hawk perched in pines at the back end of my property, I immediately grabbed the camera.  But I the last time I had used the D300 I was doing bracketed sets of the Christmas tree and I had unknowingly left the settings that way.  Well, sunlit medium bright bird on a predominately neutral back ground...might need some exposure compensation... long story short, I blew it, I dialed over the bracket set and blew out the image...

If it weren't for having shot in RAW the image would have been trash..if this was my daughter at a dance recital I would be dead meat...  But shooting RAW saved the day..  Below is the before and after...  Not an award winning image, but it proves the point..