Why the 70mm? It has excellent IQ so it should hold up well with extension. Other SFL lenses you have also have excellent IQ, but the subject-to-camera distance will become awkwardly short. Try it with the 40mm compared to the 70mm. You'll get even more camera-to-subject distance with the 55-300mm, but as noted, the focus goes screwy if you attempt to zoom. I would try your Sigma 52mm close-up filter on the 55-300mm with a 52-58 adapter, AND on the 70mm with a 52-49 adapter, although you won't get the same image size with the 70mm. I don't know the diopter value of the SIgma close-up unit, but if it is less than +1, it probably won't give sufficient close focus with the 70mm, but will give good close-ups on the 55~300 set at about 200mm.
Fuji made several expensive, highly regarded "medium format" roll film cameras. These "super Leicas" as they were called generally have fixed, non-interchangeable lenses because of linkage to between-the-lens Compur-type shutters (Hasselblad is about the only camera that successfully tackled Compur-shutter linkage). The Fujis generally had normal or slightly wide lenses. Filter-thread mounted focal-length changers, available in multiple diameters from about 2X tele to fish-eye wide, are intended for VIDEO. They degrade IQ significantly, but in video recording, slightly different detail is recorded in sequential images, and your brain assembles these into a single image of much better IQ than any one image if viewed by itself. I used both 2.2X and 0.7X units on an early Fuji super-zoom digital (28~300mm equivalent). The wide was better than the tele, the latter being little better than just enlarging & cropping an image taken without device.
The Fuji 6X9 is best suited to carefully composed, tripod-mounted B&W landscape, stationary subject & studio photography. It is capable of producing deeply detailed negatives with wide, subtly graded tonality. If you want to include more or less, move the tripod. Do not try on-the-lens devices. It is a camera for thoughtful photography - sort of a compact, portable view camera without the adjustments.
---------- Post added 03-27-14 at 08:01 AM ----------
There are many-many books on taking macro photos. Two of the best that I have were published by Kodak (!). They are filled with technical information, graphs of depth-of field versus diffraction degradation over a range of f-stops down to f64 (present on some "process" lenses, notably the highly regarded Red-Dot Artar). Advice in some of these no longer applies. For example, compiling fragments from two different images by cutting and pasting prints then rephotographing, reprinting, and touching up rough spots in the final print with something like Spotone.
A really good on-line site for macro - BUT DO NOT BE INTIMIDATED BY THE TECHNICALITIES AND EXOTIC LENSES:
Extreme Macro Photography
AND, once you get a 100mm macro, it will trump any/all other methods for IQ and convenience for my perception of your photo interests.
Last edited by WPRESTO; 03-27-2014 at 05:06 AM.