Thank you very much for the great input , and its a lot input for me 
im really new in the MF digital world and you have to take so much into consideration and relearn your workflow 
, its quite challenging 
@ jason
the sinarback solution sounds really interesting, the reason i have never looked into sinar is because i always thought they have no back display for fast image check, all backs i had seen were non display backs, maybe the new line changed that, and the changeable adapter plate sounds promising
im really thinking of something in the p25+ or Aptus II 5 area , the older Aptus 75s would be great too, thx a lot ulf and yair for the tip!
i think i will try to post a "want to buy" thread here in the forum , perhaps some has updated their older backs and would like to sell their older ones....
@ yair
what are the price the leaf adapter plates are going for? RZ and GX680III ?
@ Theodoros
thank you very much for your offer, so yours is an RZ adapter for the sinarbacks ? Where could i get into contact with graham?
Luke -
As has been pointed out, the biggest disadvantage of using a digital back on an RZ or GX680 is the lens crop factor. It is not uncommon for someone with an RZ to augment their RZ with a Phase One/Mamiya 645 camera, and for wide shots, switch from the RZ to that camera, and gain auto focus as well for those situations. That said, if you don't shoot wide angle, that is not an insurmountable issue. The RZ and GX680 cameras are actually extremely popular with those who use them. Someone coming from a non-medium format background might have the impression of - My gosh, run away - or - These are awesome cameras....
They are awesome cameras. From a traditional perspective, they feel like "real cameras". They're big, heavy, complex looking - though complex looking from the standpoint of how manually do you adjust them, not which buttons or menus should I use. Very different from the mainstream cameras of today. Even with the reduced lens coverage, looking down into a waist level viewfinder on a 6x7 or 6x8 camera is a wonderful thing. I've always loved the focusing rail of the RZ. And there is nothing today like a Fuji GX680 - a medium format camera that has in-camera tilt/swing movements with a variety of through-the-lens viewfinders. We still have numerous clients using them in multiple set studios because of their unique feature set.
Using them outside the studio in less than locked down conditions does present some challenges (though not without ways to overcome them).
Both the Phase One and Leaf digital back products can be used on a Fuji GX680, but both require the KaptureGroup OneShot solution. neither Phase nor Leaf ever made a front end comm solution for the Fuji. However it is possible to utilize the KG OneShot Box for the Fuji in a pretty inconspicuous manner with a custom tripod mount that tucks the box away. There is no digital back that can shoot to a Fuji without some sort of cabling, so cables are a given regardless.
On the other hand, you can connect a Phase One P40+/65+/IQ140/160/180 or any Leaf Aptus/Aptus-II to an RZ/RZ Pro with a simple $20 sync cable, no wake up box required. However, a P25/25+ (or any P45+ or older P back) would have to be in Hasselblad V mount and require the Phase One V mount > RZ adapter interface, which automatically wake those backs up (the newer Phase One backs don't necessarily require a wake up).
However, an RZ Pro-II D would not require a cable of any kind when used with the Mamiya Pro-II D adapter and any P40+ or newer Phase back or any Leaf Aptus/Aptus-II back.
Steve Hendrix
