Monday, May 9, 2011

Making Something Out of One Poorly Exposed Shot Using HDR Pro

What happens when you have one shot that has some potential, but it's a little over exposed?  You know you can bring it back using Adobe Photoshop CS5's HDR Pro, but you still have only the one shot.  You can try CS5's HDR Toning, but that'll only take you so far.  If only you had three shots about three stops apart.  There's actually a pretty easy way to do it if you just happen to have Adobe Photoshop Lightroom 3.  (You can probably do it in LR 2, I don't remember if it was part of the first iteration.)  One of the things available to you in LR3 is the ability to make Virtual Copies.  Virtual Copies have several interesting uses.  The first that comes to mind is variations.  You can try out an image as a B&W, or High Contrast, or a Split Tone and the beauty is that it doesn't take up any disk space.  You can think of it as a family tree type structure, with the "real" image as the trunk.  You can make any number of first generation changes and then make changes to that generation and so on.  You can see how the "branches" would form a tree structure.  What happens is a set of "What-If" type statements.  Everything will point back to the original image.  The statement might be something like "what if I take this image and make it B&W (the first Virtual Copy) and then make a Virtual Copy of that and make it sepia toned and then make a Virtual Copy and do a Split Tone of the sepia and on and on.  The key is the Virtual Copy.  To learn more about how Virtual Copies made today's image possible, hit the "read more".
Well, like I said in the opening sentence, I had these one shot and if wasn't even that great a shot at that.  I wanted to play around and learn something.  I knew I'd need a much darker copy of the image and a somewhat lighter copy.  In LR3 I tried making two Virtual Copies and adjusting each as they stood.  They looked exactly like what I thought I needed.  Selected all three and went to making a three shot HDR image (Photo/Edit in/Merge to HDR Pro in Photoshop).  A dialog box came up that sort of surprised me.  Each one of the three looked exactly the same.  The careful adjustments in exposure were gone.  The dialog title was "Manually Set EV".  It showed one copy of the image and had a picker at the bottom saying 1 of 3, 2 of 3, 3 of 3.  It gave the settings that the shot was taken with (1/60 sec, F 4, ISO 100) as one option and EV as the other.  I could have set one copy as is, one copy as 1/7 sec, F 4, ISO 100 (or 1/60 sec, F 1.4, ISO 100 or 1/60 sec, F4, ISO 800) .  I could have set the third copy totally the opposite way, 1/500 sec, F 4, ISO 100, etc.  The other method was to set the EV values at -3, 0, 3.  Seems much easier to me to use method two (less math). 
By setting the values in that dialog box PS CS5 goes to town with the calculations necessary to build an HDR Pro image.  It brought up the typical HDR Pro dialog box and all normal sliders available.
Everything after that was pretty typical.  It's a different interplay between Adobe Photoshop Lightroom 3 and Adobe Photoshop CS5 demonstrating the synergy between the two applications.