[rally]

The success of adding a camera lens to a CCD camera is at least partially dependent on the metal back distance of the lens to the CCD image plane.

Here is a copy of an older list I found sorted from shortest to longest.

27.8 mm Leica (M bayonet)
28.8 mm Leica (screw)
28.8 mm Canon (screw)
31.5 mm Miranda
37.8 mm Alpa Bayonet
40.5 mm Konica Autoreflex
42.1 mm Canon (FD and earlier)
43.5 mm Minolta
44.7 mm Rollei 35
44.7 mm Voigtlander
44.7 mm Exacta
44.7 mm Ikarex BM
44.7 mm Topcon DM
45.5 mm Pentax K
45.5 mm Contax RTS
45.5 mm Petri Bayonet
45.5 mm Praktica/Pentax ###
45.5 mm Rico Bayonet
45.5 mm Yashika FR, FX
46.0 mm Olympus OM
46.0 mm Contarex
46.5 mm Nikon

### also includes Alpa 2000 Si, Argus, Chinon, Contax D and S, Cosina, Edixa, Fujica, GAF, Ikarex TM, Mamiya/sekor, Petri, Pentacon, Ricoh, Spiraflex, Vivitar, and Yashica SLRs with M42 Universal mount.

The list is not up to date because it doesnt include Olympus DSLRs (which btw are very short) and others,
So it would pay to double check your lens first, but I reprinted it for the discussion, since I couldnt quickly find a better one !

As you can see the Canon lenses have a very short metal back to image plane distance especially compared to a Nikon.
So what can be done on one brand/type of lens may not be achievable with another - with Canon being amongst the least flexible.

So success is highly dependent on your particular camera and lens and the distance from its housing to the CCD, the adapter you want to use and anything else you may want to insert in the middle - filters, OAG's etc etc

Cheers