@Ganesh Sir, I will surely try out the different play-arounds on the brightness and the border. The one in your link is wonderful, I couldn't have had such images. I tried several of them and one thing I was thinking is to be on a different side, tried to capture the circumference than the surface and it worked out different. I could have had a better PP. Thanks for your insights and guidance.
@Pramod, I had a bigger image and thought of cropping it, so that it would look something similar to the Iris (Eye). And it worked but not surely in a better way.
As you had mentioned choosing better DOF is a challenge. Thanks for sharing your views.
@Ramesh, I am passing the image through illustrative forum, here is the
Link, hope it interests you. The only trick as I had mentioned worked better here was when the focus was on the circumference. Thanks for your views.