I have an Olympus 40-150 for my EM-5. On rare occasion I want to go beyond the 150mm range. While one option is the digital teleconverter in the camera, I am exploring purchasing a telephoto conversion lens as another option. There are three models I have seen discussion about: - Olympus TCON-17 (1.7x) - Raynox DCR-1540Pro (1.54x) - Raynox DCR-2025Pro (2.2x) All provide the magnification I am after. What I want to make sure of is that the image quality holds. In that regard, the TCON-17 seems to get the best reviews. One downside on the TCON - its back thread size is 55mm, whereas the front thread on the 40-150 is 58mm, so I will need to use a step-down ring. Downside aside, any thoughts on using the TCON-17 with an EM-5 and/or the 40-150 lens?