Originally posted by kaseki I can also try my FA 45mm which has a 58mm filter thread.
Bzzzt. The 45mm has a 67mm filter thread, so no go without a step-up ring. I may have one in a ring light kit, but that will be another day to look for.
Two images are shown below using all three 645-A extension tubes and the 75mm standard lens. The first is with the lens reversed using the adapter/attachment kit, and the second is without using the lens not reversed. The object is an avatar on my BenQ monitor screen. The avatar is of a Windows aquarium program that can be made to run on Linux. The width of the mini-aquarium is 19.5mm, approximately. Images are PF reductions from the 645Z jpg files. No post processing. Parameters (available to the camera) are in the exif files.
This is only a functional test. Target objects of finer detail need to be used to see if there is any difference in apparent resolution.
In my view, the slight gain in magnification from lens reversal for this lens is hardly worth the loss in camera control of the lens. Also, focusing via the focus ring seemed to be numb for the reversed configuration requiring tripod displacement to achieve focus, whereas the normal configuration, also with the extension tubes, allowed easy manual focus.