19 Aug 14. All right, dig up last Friday's image and let's compare. Friday's shot was primarily a study in color (reds), today it is a study in luminance which we'll approximate with (B&W). Over the last couple of years you have heard me ramble on about shooting in RAW vs jpg and while I realize that those of you who are avid digital photographers understand the difference, I'm not certain that applies to everyone. So here is an opportunity to perhaps make that somewhat more clear. In simple parlance, luminance refers to just the light values in an image, ranging from total black to total white, and everything in-between. Think in film terms of a B&W negative which is basically nothing more than that. A RAW image is the same thing, a recording from the camera sensor of the light values that are striking the sensor, and nothing more. There is additional info that is carried along with those light (luminance) values that the software uses to add all the details into the final output - what you see either on the back of the camera or displayed on your monitor - but the RAW file itself is just a recording of the light values for each pixel ranging form 0 (black) to 255 (white). A B&W image is the closest one can get to grasping the ides of a RAW image but of course it too has all the additional info added to it. The advantage then of the RAW file is that we can manipulate it to be whatever we want the final output to be. We cannot do that with the jpg because it is already a manipulated RAW image, manipulated by the camera's software, to be what the engineers who wrote that software think is the best way to manipulate a RAW capture. The choice then becomes who gets to decide. Now let's play a bit with a RAW capture that I've provided in two versions, both now being jpegs. Do one of the following, whichever is easier for you. Either place the color image from Friday next to today's image, or place them on top of each other so you can cycle between them. Look first at the color image and study it for a few seconds, then look at the B&W and do the same. Do you notice anything different about them? Remember, they both started from the same RAW capture. Obviously one has "color" and the other doesn't. But that's not the question. In which photo do you see more detail? Think about it for a moment before you answer. What happens when the "distraction" of color is removed? Now if we were back in grad school I'd suggest that the answers to these questions are left as an exercise for the student. IF you keep what I send, and I know that some of you do, go look at other B&W/color couplets that I've shared throughout this year and make the same comparisons. What are your conclusions? Unlike the color version I shared on Friday, in which there really wasn't a lot of ways to present it that you would have found acceptable, in the B&W approach I can create multiple versions, all of which you would find acceptable because color is not there to get in the way. This version could have been created from a flower that was yellow, or orange, or white, or pink, or any of several other hues instead of red and it would still look the same if I so desired. What does this say to to you about color? Is it as important as luminance? Is it important at all? And just what does any of this have to do with photography? Nikon D300s; 105mm Macro; ISO 400; 1/320 sec @ f /10. ---- There will be a test.