In this issue we've got a complete review if the exciting new color correction book from Dan Margulis, 	, as well as info on some great new products that  	have been introduced just in time for Christmas. In particular, check out 	 for  	the Nikon D200 specs. We've also still got a couple slots for our second  	Grizzly Bear & Puffin week in July 2006, so 	.
The  	Photoshop LAB Book: The Canyon Conundrum
Could you fix the image on the left of Delicate Arch?
Can you turn  this image
   | 
  | 
Into  this image?
   | 
 If you are experienced Photoshop user, I'm sure your answer is "yeah,  	probably, but it might take some work." The first time I worked on those  	images it took me a long time also. Then I read Dan Margulis' book  	 and discovered how useful the LAB color space was  	for color correction. Sure, I'd always known that it could be used as a clever way to  	do Luminance sharpening and some tone correction, but never thought much  	about using it for color correction. Now it is one of the first tools I  	consider when I have an image that requires some color heavy lifting. 
 | 
After reading the book (or more honestly flipping through for the tidbits  	I could quickly understand) I was able to re-process this image and the  	others shown below in  	only a couple of minutes each and produce results that were superior to what  	I'd accomplished previously with oodles of layers, masks and fiddling. What  	fun! A more thorough reading revealed a whole new world of color correction  	opportunities using the very powerful LAB colorspace.
The Magic of LAB
As someone fascinated by the way human vision works, I've always been  	interested in the LAB colorspace. For those not familiar with LAB, it is a  	representation of color that separates the luminance (overall brightness or  	"lightness") or "L" channel from the color channels--"A" and "B". While we  	most often think of the human visual system as being RGB, it also relies  	heavily on the contrast between Red and Green and Blue and Yellow. Not by  	coincidence, those are the A and B channels in LAB. The result is a very  	powerful colorspace that can cause dramatic changes in our perception of an  	image by creating and destroying contrast easily and quickly. And by having  	the L channel separate from colors it is possible to do operations including  	sharpening without accidentally adding color casts.