Making small edits to a DNG in Photoshop

Question

Hey there, I have a very simple question!
•Is it possible to edit a DNG file (using Lightroom's "edit in" option) in Photoshop CS3 while still keeping all of the image data intact?
e.g. I go to edit a DNG file.. right click image>edit in>CS3.   TIFF / 16-bit / ProPhoto RGB file handling options. I do whatever it is that I need to do in CS3 cloning and blurring and save the file which then creates a copy in Lightroom. When I edit this copy in Lightroom it doesn't hold all of the information it use to..meaning there's nothing that can be brought out in deep shadow or blown out highlights; whereas if I was working with the DNG/RAW file I could just under or overexpose and there would be something to work with.
I hope this is clear! Thanks,
-jope

Answer 1

This is to be expected. RAW files usually have some headroom left over above white since usually not all three channels are completely blown out and you can still recover some info from them and reconstruct blown out areas, which is what Lightroom does with the RAW file. On the shadows side, there is usually a lot of info hiding that you can bring out by several methods such as exposure compensation, Fill light, lowering the blacks, etc.. Rendered files such as tiff however, do not have this headroom. White is white, and black is black. Nothing you can do when a pixel is all black or all white. So as soon as you bring your file into Photoshop, you are stuck with the rendering you had. Sometimes you can get around this by using smart objects in Photoshop, but not all operations (such as cloning and healing indeed!) can be done on smart objects.