Originally posted by Marc Sabatella I don't know about potential, but back to the subject here: even if Canon & Nikon's system *might* work a little better on the small handful of lenses that offer it - virtually all zooms - Pentax system *definitely* works better on primes, since Canon & Nikon basically don't offer any with IS/VR except for a handufl of mega-expensive long telephotos.
Pentax system offers an advantage but not that much - around 1 stop, I mean in real life. If you have to go further the results are not always predictable and / or repeatable. This applies to lenses such as FA31, FA43, DA70. Maybe my hands are shaking, but this procedure, to wait the "hand" and to be careful even about the breathe is not so effective (at least for me). Of course it is so welcome (better than nothing)
On the other hand, Nikon system is just so much better. I'm not talking about mega-expensive lenses. Take for example the 70-300 VR (around 480 Euros in Greece). It works just instantly from the first press of shutter, in panning, in shaking hands, from moving vehicle etc (there are two options for operation) and the advantage is easily around 4 stops ! So their system does not work just a little better. It really works much better and in a predictable and constant way.
I am not talking from technical specs. But I have both systems and work them a lot. For Nikon primes the old rule of thumb min shutter speed = 1/focal range works just fine, but with D700 high ISO capacity, really there is no worry.
Bye
Paul