It's fun to experiment with the S-M-C-Takumar 55mm/F1.8! This morning I mounted this lens in front of some (M42) extension tubes and re-photographed the mushrooms I shot earlier this week with the SMC Pentax-A 100mm/F4. It is quite a challenge to make photos with this combination, because one has to adjust for exposure fairly much, depending on the aperture. But once you get used to this, it is a great experience! Here are some of the results; I made the pictures somewhat larger here, and they are also clickable.