I just found a used Raynox DCR-250 at my local store for about 35 USD. I had heard good things about it but I was nevertheless blown away by how well it works on the P45-175! It is easily the best makeshift macro combination I've tried compared to previous experiences with the O12-40, O12-50, O45, O40-150R and P45-175 plus various extension tubes and achromatic dioptres. These are at 1.88x magnification (plus some cropping), lit with off camera flash. The working distance at 175mm is great but getting into the right focusing range at high magnification can be a challenge - I'm finding that I typically need to zoom out to 45mm for initial subject acquisition.