Been thinking about my 28mm on my Lumix. Given the 2x crop factor it should be like 56mm (equivalent*), but I don't think it is. I stood in the same place, and shot with that combo, and with the 35 on my K-30 (53.5 equivalent). Way different, which surprised me, as my 30 (46 equivalent) and 35 (53.5 equivalent) were much closer when I looked at them back to back - and that difference in focal length is greater.
Thinks... The adaptor is as long as the lens. As long as my 50mm lens, which is actually 50mm long.
So ... Acting like a small extension tube perhaps?
I think I will play with this combo through the month - including checking out infinity focus. Probably just jpg, as the RAW files from the Lumix are kind of crap.
*for the purposes of not prevaricating endlessly throughout this post, please take it as read that I know they're not equal, but there is at least an equivalence in terms of field of view.
Also, thinking about the themes this morning... Aside from the clang associations, they can be mixed and matched together quite nicely, even all four at once: a B&W architectural shot where the main point is the play of light on the texture of the surface.
or other combos as one might or might not fancy.
Have fun. 8)