I'm HUGELY excited about both the 180/190mm lengths and the 300mm for macro.
At this point, I mainly want a lens that improves substantially on the color and contrast of the EF 180mm f/3.5 L Macro USM. I've owned that lens for a long time, and it is a critical lens for most of my insect work--I seldom use the 100mm length anymore as the extra working distance is critical for so many species I work with. While the 190mm f/4 2X is intriguing, I have my doubts about how well a 17-element design will perform, and suspect the 14-element 180mm might perform better optically. Unlike the 100mm focal length, I don't think this lens needs any value-add features (like 2X) to become a strong seller. While less important than getting a body with the features I want (now being fulfilled by the R1), the absence of an RF replacement was a minor consideration on whether to continue waiting to migrate to the R lineup. I hope, hope, hope that Canon will stop viewing their key macro lenses as amateur sales and make this lens the best they can, damn the price.
The 300mm design is a curiosity. When I bought the EF 300mm f/4L IS USM a long 26 years ago, I loved what it could do with my old Elan IIe. But I eventually outgrew it and replaced it about a dozen years ago. My fear is this will be designed with an amateur price-point in mind and won't be up to snuff. The old EF lens focused to 1/4 life size, which served me well for close-ups of hummingbirds and such. I'm not sure how easy it will be to follow dragonflies with such a narrow cone. If the optics are top-flight, I would probably buy this too, even if I didn't use it as extensively.
R1, 50mm, 180mm, some wide angles... darn, my wallet feels palpably lighter already!
