Originally posted by photolady95 Focus ring should be set to close focus, not infinity.
Either are OK, at least in my book. You'll get more magnification with the lens at MFD, but if you're getting the shot you want with the lens at infinity focus, then that's fine too. AFAIK, the stronger the diopter, the less the focus ring will have an effect. Also, obviously, the less a lens can go to close focus on its own, the less using the focus ring will have an effect. Finally, I think the longer the lens, the less using the focus ring will have an effect. FWIW, the DCR-150 is a +4.8 diopter, the DCR-250 is +8, and the MSN-202 is +25.
One more with D-FA 100mm WR and DCR-250: