Mamiya ZD back: what are the side contacts for?

[ondebanks]

I don't see this mentioned in previous ZD threads. The ZD back's user manual is silent on this also...

Does anyone know, what's the purpose of the recessed vertical strip of 12 electronic contacts on the ZD back?


There are no corresponding contacts on the 645AFD series bodies.
There are no corresponding contacts on the RZ67 ProIID ZD adapter (HX701).

There is a corresponding protrusion with 2 (not 12!) contacts on the RB67 ZD adapter (HX702), and on the 4x5 ZD adapter (HX401).

Hmm...this might be a wake-up thing, but since the 645AFD and ProIID/HX701 wake the back up through the usual horizontal contacts, and since the RB67 and 4x5 adapters also have these horizontal contacts and their own built-in power source, why are the 2 vertical contacts also needed?

Related question - has anyone managed to use any digital back other than the ZD on the RB67, using the HX702 adapter directly (no lens-to-back cables)? In particular, I'm thinking of the Phase One backs that need a wake-up signal?

Ray

[ondebanks]

Anyone?

Surely a PhaseOne/Mamiya-Leaf dealer can answer this simple question? You guys still sell the HX701 and HX702 after all!

Ray

[yaya]

Hi Ray,

I've asked my colleagues at Mamiya; The top 2 contacts are for Ground and for power supply to the adapters' CPUs (so the ZD back powers the adapters)

The other 10 do not have a function but they were placed there to allow for future expandability.

Hope this helps

Yair

[homeiss]

I just received my HX702 adapter a couple of weeks ago. If you want to mount a Leaf or Phase One back you would have to remove the side contacts you're refering to. They are held on by two tiny screws. Once removed it reveals 12 contacts just like the ones on the ZD back. Then you should be able to mount a Leaf or Phase back to it. Since the adapter wouldn't receive any power at this point I'm guessing you could use it as a dumb adapter and use a sync cable straight from lens to digital back?

The HX702 seems to be the only adapter for the RB67 that actually maintains the ability to rotate, which is nice. Leaf has an adapter, but they are just two different plates, one for each orientation.

[ondebanks]

Excellent - thanks for the replies, Yair and homeiss.

The HX702 was the one I was most interested in, as I can currently get it plus an RB67 ProSD body for around €650 combined. In contrast, it's hard to find an RZ ProIID and HX701 for under €2000. The lenses I am interested in are common to both.

Yair - could I trouble you further to find out the voltage and current specs drawn from the ZD, when it is powering the adapters? I don't have a ZD back, and like homeiss, I would intend to use this adapter with a different 645AFD-mount DB. After removing the 2 tiny screws, I could feasibly rig a connection straight from the HX702 adapter to a separate battery, if I knew what electrical spec the adapter requires.

Thanks again,
Ray

[homeiss]

I know what you mean about prices for RB versus RZ... I had an RB67 Pro for 5 years, and just before I ordered the HX702 I picked up an RB67 Pro-S body for $53 on ebay!

I should have been more clear. I actually have a ZD back and use the HX702 with it. If I ever upgrade, I would definitely want use this adapter though.

Operation of the HX702 is a little bit weird. However, I have never had my ZD give me errors like it does when I use it on my AFD! If you push the shutter release halfway down the adapter lights up for 5 seconds. If the shutter is not fired within the 5 seconds the ZD just records a black frame. So for long exposures, you seem to be able to put it in Mirror Up mode then fire the body. The adapter will light up and as long as you fire the lens before the adapter light goes out in 5 seconds it will record the image for however long you want (I've only tried up to 8 seconds). The adapter "knows" when you push the shutter halfway because it uses the same mechanism that checks if a darkslide is present or not. So when the shutter is pressed, it pushes on the adapter and completes the circuit which then lights up the adapter, thus preparing it for capture.

I would be very interested to hear how it goes if you do try and mount a Phase back to it.

-Cory