A gobo is a mask you put over your light and it casts a pattern.
I loved the bark of this tree. After I began photography I thought I could help a friend of mine by sending her pictures of flowers every day. That was fantastic - esp for me - because I began to appreciate flowers, and then I learned about and began to appreciate macro photography. Once there were just no flowers around I asked what else she liked and she said bark. Now I see so much more in bark and find it fascinating.