As the owner of "regular" ALPA cameras and the FPS, I've been intrigued for a while now about how/whether the range of tech-cam lenses that work with the FPS would be extended beyond the existing SB34 (34mm short barrel) lenses.
ALPA did mention right at the launch of the FPS that SB17 lenses would be able to be used in the future, and I'm happy to report that lenses in this new mount should be available within the next 3 months.
Here's the background...
The regular ALPA 12 series cameras (TC, STC, Max, etc) separate the lens from the back by a distance of 11mm. So, all Long Barrel ("LB") lenses from ALPA have inherent in their mount design the understanding that the lenses will be mounted 11mm from the back.
Short barrel ("SB") lenses come in one of two shortened mounts - SB34's have their mounts shortened by 34mm, and SB17's have their mounts shortened by 17mm.
On the regular ALPA cameras, this means that you can then take advantage of the various 17mm and/or 34mm adapters placed between the lens and the back (I'm ignoring macro-use here and just discussing how to retain infinity focus).
The FPS though has a different spacing between the lens and the back, because it has to accommodate the focal plane shutter. What this means is that you can't mount any of the regular long barrel lenses on an FPS and retain infinity focus.
If you look a the second PDF diagram under the section "The ALPA 12 platform enhanced" on this page, you can see that (currently) you can only mount SB34 lenses to the FPS, and need to include the 17mm FPS adapter to get the right flange distance.
Worth pointing out at this stage that the FPS differs from the regular ALPA 12 cameras in one other crucial way - the mount on the front of the FPS, where lenses and lens adapters connect, is the opposite to the other cameras. It's a receiver mount (it doesn't have the hooks).
The reason for this is so that you can mount ALPA cameras to the front of the FPS, not just lenses.
Existing ALPA lens mounts - LB, SB34 and SB17 - cannot be directly mounted to the FPS. You have to use an FPS adapter to mount them. The FPS adapters are different to the adapters for the regular cameras because they have the hooks on BOTH ends. (As an aside, I hadn't actually realised this when ordering my FPS and accessories - I got the FPS 17mm tilt adapter thinking I would also be able to use it on the TC and Max, but of course it can't be used on those cameras.)
Going back to that PDF I linked to earlier, there is currently no way to mount SB17 lenses to the FPS and retain infinity focus. Notice that SB34 lenses need a 17mm spacer to mount them to the FPS. The maths here is simple - the SB17 lenses therefore would need a 0mm spacer. Which would not be possible. It is this that has been puzzling me for ages as to how an SB17 lens could ever be mounted on the FPS.
A new FPS-specific SB17 mount that includes the hooks on the lens barrel itself This will allow direct mounting of the lens to the FPS, with no need for an adapter.
But wait, I hear you object - if the new SB17 mount has the hooks on the lens itself, you then won't be able to mount it on the regular cameras, will you? Nope, not with the regular 17mm spacer, you won't. So, there will be a new adapter with NO hooks on it (receiver at both ends) so that the hooked SB17 lens can be connected to the hooked camera.
The adapter thing at first seems confusing, but it's actually pretty simple -
Regular camera, standard SB34 or SB17 mount lens - adapters are receiver on the camera side, hooked on the lens side.
FPS, SB34 - adapters are hooked on both sides.
FPS, SB17FPS - no adapter necessary.
Regular camera, SB17FPS - adapter is receiver on both sides.
Currently - excluding BTO options, only the Rodie 50HR and 90HR, and Schneider 120 (in SB34) can be mounted to the FPS. Hopefully we can look forward to SB17FPS versions of the Rodie 32HR, 40HR and 70HR's, and the Schneider 60 and 75, in the coming months.
The joys of a modular system!