I ordered 49mm to 58mm macro reverse adapter from Ebay last week. With this adapter I attached Pentax 50mm/1.4 M to my Sigma 105/2.8 macro lens.
You can get really close with this combination as the magnification is about 3:1. Only downside is that you must get really close to your subject.
Drops were about 1-2mm wide. I also used my DIY flash diffuser in these photos.
