Is the AF 35mm f/2 really that good? I have not shot one before, but how is it compared to the AF 28mm f/2.8? Is it worth getting the 35mm when one has a 28mm? I'm thinking of getting a macro lens, at the moment I am using a reverse ring BR2a / extension tubes to get the close-up shots. However the DOF is so thin, one slight camera movement and the subject is out of focus. Will this happen with a dedicated macro lens like the highly praised Tamron 90mm?