Even with a strobe and spotting light, they're very sensitive in S-Macro. On the plus side, those sorts of subjects generally aren't moving much, so I try to frame them with 4-5 shots and keep the best 1-2. Usually most are out of focus. One solution is a close-up lens, which lets you back up a bit and get more light on the subject and allow the camera to bounce the focus beam a little better. Many on this forum use two of them stacked and then zoom a bit for focus.