Hi,
Yes, and the 500 series outlasted the 200 series.
There is a principal problem with focal plane shutters, and that is that accelerating the shutter curtains induces reversed motion on the camera body. It is called conservation of momentum. Exactly the like phenomena as firing a gun, there will be recoil. Now let's assume that we need 1/500s sync time, so front curtain would have completed it's travel and second has still not moved.
Let's assume that curtain travel time must be below 1/1000s to allow for 1/500 s sync time. Let's also assume that the shutter travel is 50 mm on a MFD. That would mean that the shutter travels at 0.050/0.001 50 ms/s, now let us also assume that the camera weight is about 2 kg and shutter curtain weight is say 10g. So camera would move with 50 * 10 / 2000 = 0.25 m/s. Assuming shutter time of 1/500 the motion would be 0.5 mm.
Obviously a tripod or hand holding the camera will slow down that motion.
With a central shutter the moving masses are smaller, but most of all the different blades will accelerate in different direction, so the forces on the camera will cancel out.
If connection between camera body and tripod is very solid the whole thing would act as single coupled mass.
Now, would we go to 135 format, shutter travel would be less, say 30 mm and shutter curtain would be proportionally smaller. So it is easier to make a low vibration and high speed shutter for DSLRs.
Best regards
Erik
OK, got it: you are talking about why many people prefer having a focal plane shutter available, as in all current MF cameras except the Hasselblad H system.
So we seem to agree: nothing to do with the camera being an SLR or not. And not much to do with whether leaf shutter lenses are _also_ offered (Mamiya/Phase One 645, Pentax 645, Leica S2.)
It is interesting to me that Hasselblad had some focal plane shutter 6x6 bodies for a while, the 203FE and 205FCC, but reverted to leaf shutters only with the H system.