All this argument here is reminiscent of a storm in a tea cup ...
To Bernard's original question, if you want the simplest tech camera that'll provide tilts and swings and rear rise/fall then just go with a Cambo Actus DB. I can use this with anything from a Rodie 23HR through to, well anything long given a long enough base rail and bellows. Ditto with a Linhof Techno, I just prefer the size of my Cambo.
And for Theodoros, it tilts the lens around the optical center, assuming that the optical center is in the middle of the lens board. The tilt mechanism moves the entire board in an arc around that nodal point (unless you've raised the board - there's an optional front shift mount point for it on the base).
I've owned the Alpa for many years and used their tilt adapters. It is true that the axis of the tilt is behind the lens and in a fixed position which technically will move relative to the optical center of the lens if you change focus with the helicoid. However, as has been pointed out a number of times, it is really not difficult to use in the field and just takes small adjustments to dial in front/back focus and if necessary you may have to adjust a little rise/fall to compensate for the image shifting slightly.
Sure, there's theoretical perfection that Theodoros is obsessed with and then there's PRACTICAL usefulness that the pancake technical camera tilt functions provide. In this respect all of the pancake cameras are 'flawed' but they are nonetheless very usable and I've certainly never had any concerns about quality drop off when using tilt adjustments.
Finally there's also one advantage I found with the Alpa which was I could put the tilt adapter on the back of the camera and tilt the sensor vs the lens for looming of the image. Not quite as easy as doing it with a proper 4x5 view camera but still doable in the field, especially with decent CMOS live view. That's a difference between the Alpa approach and the Arca, although you can achieve the same thing with tilting of the entire camera body and then adjusting the tilt on the camera (Theodoros will have a mental breakdown over the geometric accuracy of that set up I'm sure!
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