Originally Posted by macdonaldj2

I was like you when I started to shoot SLR, I thought the higher the F-stop the sharper the image, but then I learned about diffraction, for the most part f10-f13 should allow for plenty of DoF. You might just want to leave the shutter open longer, so instead of 30 seconds, do one full minute and see what that looks like. The starburst effect can be achieved by a filter if you really wanted to have it. I also learned that when doing good or real macro work, then you should use a higher F-stop, or if you were doing some homage to Ansel Adams. Personally I rarely shoot over f13, f10 in most cases for me is extreme. Hope this helped...