DWU2 wrote:
Keni - thanks for your great post. I ran into a couple of issues where PS wouldn't let me use the art history brush - maybe you know the solution. First, I got a message that the A.H. brush doesn't work on 16-bit per channel images, so I converted to 8-bit. Then, I encountered the error message I have attached. Any suggestions?
I finally remembered how to fix that issue. After you have converted your photo to 8-bit you will need to go to Window and click on History. This shows you the history or list of changes you have made to the image since you opened it in PS. Click on the one that says 8 Bits/Channel then close that window and open your art history brush. It should work.
Basically every time you do something in PS it takes an internal snapshot. That is why you are able to undo an edit. PS goes back to the snapshot it took prior to what you just did. The Art History brush uses that history but initially only looks at the original image you opened. If you make changes to that image it no longer matches the original image in the history so you have to tell the Art History brush to look at the newest version in the history. I hope this helps.