Yes, it is the 17mm TS for FPS. I think(IMHO) the best advantage is to use higher shutter speed than "normal" tech camera without the need of ND under a sunny day and wide-open aperture for a paper-thin DOF.I have that same gear as you Mike: Lens, IQ180, FPS, Cube.
but just the straight 17mm spacer, not the TS version - that's the 17mm TS or the ? 6mm one?
is there some advantage to using the FPS for longer lenses I'm unaware of? So far I've been using mine with the 50mm HR, and like that combo. great to be able to keep shooting without taking your eye away.
Regards
Michael