Fuji, like most lens manufactures, made many lenses for special purposes -- and most of these were not
available to the general, public, consumer market. Good examples are lenses made to be included in special
equipment, such as fax machines, copying machines, scanning gear, and mini-labs (the HUGE processors for developing
35mm film and producing prints). Most of these lenses, if you can find them, can be used on standard film
and digital SLR cameras -- even large format cameras -- but it depends on the lens, and your camera(s).
These lenses are hard to find. As a result, prices are all over the place. Some of these lenses can be bought for just a few bucks -- simply because the seller has no idea what it's used for! Other sellers ask absurdly high prices -- sometimes several hundreds of dollars!!!
One of these series of special lenses are the EFC series -- EFC & EFC-II. These should not be confused with Fuji EBC lenses. EBC was the name of Fuji's exclusive multi-coating process, and was applied to many of their optics from enlarging lenses to camera lenses -- and to the EFC lenses, below. If you do find one, chances are it will not come with a shutter. It may be attached to a plate or have a strange, unspecified, rear thread (see above). So you will have to figure out how to attach it to your gear. Here is an example of a 35mm setup:
And here is one on a 4x5 camera:
.
Some (most?) of these EFC lenses have front filter threads that may facilitate their use (reversed) with
the addition of a reversing ring -- and perhaps a step-up/down adapter ring.
When you find an EFC lens, it may or may not have a diaphragm. If it does, the smallest/minimum f-stop is probably f11 or f16. It may have some focusing ability -- probably not. If it does, it will be minimal, but may be helpful for fine-focusing. Some may have different features than those mentioned or shown here.
Most importantly, there is no way to tell what film size each lens will fit -- you need to test it yourself. BUT, for macro work, all of these lenses will work with enough extension/bellows draw -- because the picture size increases with magnification.
Here is a "small" example:
The Fujinon-EFC lenses were made in at least 17 different focal lengths from 35mm to 140mm in a variety of styles -- some easier to find than others:
Fujinon-EFC 35mm f5.6 -- fixed aperture
Fujinon-EFC 35mm f5.6-11.0
Fujinon-EFC 41.0mm f5.0-11
Fujinon-EFC 49.9mm (you read it right!) f5.6 -- Fixed aperture
Fujinon-EFC 51mm f6.3-12.0
Fujinon-EFC 55mm f6.0 -- fixed aperture
Fujinon-EFC 55mm f6.3-12.0
Fujinon-EFC 64mm f5.6 -- fixed aperture
Fujinon-EFC II 64.5mm f6 -- f5.6-11.0
Fujinon-EFC 65mm f6 -- f5.6-11.0
Fujinon-EFC 65mm f6.0 -- fixed aperture
Fujinon-EFC 72mm f6.0 -- fixed aperture
Fujinon-EFC 80mm
Aperture unkown, but it has a 49mm filter thread.
Fujinon-EFC 81mm f6.0 -- fixed aperture
Fujinon-EFC 81mm f6.0-16.0
Fujinon-EFC 85mm f6.0 -- fixed aperture
Fujinon-EFC 86mm f5.6-11.0
Fujinon-EFC 98mm f6.3-?
Fujinon-EFC 108mm f5.6-11.0
Fujinon-EFC 108mm f5.6 -- fixed aperture
Fujinon-EFC 140mm f5.6 -- fixed aperture