Here’s the usual story: You went on that once in a lifetime experience – diving with the nautilus, took your camera with you and thought you had the perfect shot, perfect strobe position, perfect lighting. As soon as you get that card downloaded in the computer and viewed it on the screen, you gasp as the photo is filled with numerous speckles of white, it looked like there’s snow underwater! The evil backscatter is every underwater photographer’s nightmare because it takes so much time to clone/heal each and every one of them in photoshop. I would like to share a technique that i learned to make elimination of backscatter in Photoshop as easy and quickly as possible. It will work up to a certain extent only, and is not the absolute solution.
Before shot, showing numerous white speckles. (please click image to see it large)
We now open the file in photoshop, in my example, I am using Adobe Photoshop CS5. We will be working in layers.
1) Make a duplicate layer, or layer from background
2) Using your spot healing brush, content aware, heal the obvious white spots, and leave the smaller ones behind.
3) Click the filter tab, look for the “dust and scratches” option then click.
4) A window will open prompting you for two slider values for RADIUS and THRESHOLD. I put mine at 14 and 5 respectively. Click okay, and this will blur your image.
5) Now comes the fun part. On the layers panel, highlight the Background copy layer, and then press OPTION + ADD VECTOR MASK to make the mask black.
6) Using a white brush at 100%, paint over the areas with the remaining backscatter until no backscatter is visible. If it appears too much or too artificial, lower down the opacity in layers.
7) Press SHIFT + OPTION + COMMAND + E to make another layer. We will now sharpen the image.
8) Open filters tab again and look for High-Pass filter. Put radius at 3.0 pixels then press ok. The layer will appear gray.
9) Change the blending mode to OVERLAY, opacity at 100%.
10) Flatten and save your image.
Final image, with backscatter gone!
Contributed by Wendy Capili-Wilkie, an underwater photo enthusiast, frequent diver at Sam’s tours.