If you’ve shot in any studio, then you know the rules. Larger studios may require the use of protective booties on a freshly painted cyc wall or some practice the unsaid "no shoes" rule when stepping onto background paper. But, unfortunately, that just doesn’t happen and if the subject is jumping or moving look after look that background is going to get dirty. We all know the pain of re-touching that dirt.
In my opinion, it’s probably one of the more annoying aspects of studio fashion re-touching, especially if you’re shooting on white seamless paper. It's so time consuming and perhaps so costly, that many photographers and editors just let it slip by without a second thought. But, after stumbling on a tutorial from my friend Aaron Nace of Phlearn, I truly believe my opinion had completely changed. I just had to give this method a try in my own video. What used to take 30 minutes with the Clone Stamp requires about 30 seconds with this method.
Create A New Layer. Type Ctrl-J (Command-J) or flatten all the layers into a new layer using Ctrl-Alt-Shift-E(Command-Option-Shift-E).
Add Median Noise. Click Filter > Noise > Median. Then select a Radius of 15 - 30 Pixels depending on the amount of dirt and grime on the background. In the preview window, make sure the dirt completely vanishes, but the shadows retain detail.
Create A Layer Mask. Click the Layer Mask button and then tap Ctrl-I (Command-I) to invert the mask.
Paint On The Median Blur. With a decent size white brush paint on the Median blur over the problem areas and watch the dirt disappear! Be careful of any edges, I recommend using a small brush to cover the fine details around shoes or props.
Add Noise. Although I do not mention this in the tutorial, reduce the blur banding by adding a slight touch(2%) of monochromatic noise to the original layer.
I've never claimed to be a fantastic re-toucher, I just share from experience and always try to pay the knowledge forward. This is one method that will come in handy time and time again.