How does PD Prism works?

[steve_tenggala]

Hi there,

 

I finally made a plunge into MF. My RZ ProII kit comes with a PD Prism Finder

which until now I couldn't quite get how it should work. I tried to find info

about this finder, but to no avail. It's not even listed in Mamiya website.

 

As far as I know, the finder has some sort of communication port that should

talk to the body to get info about the film speed, shutter speed, and

aperture. I put the finder on, press that circle white button and the only

reading I see is A (for aperture) or S (for spot) and plus sign. A and S

switch back and forth as I switch the button mode. The plus sign, however,

turns on everytime I press that white reading button, no matter what mode I'm

in and no matter how bright or dark the scene I'm aiming at. Logically, I

thought, that plus sign is supposed to tell me if my exposure is over (and

should probably change to negative sign if it underexposes). Is this normal?

Or there is something wrong with the finder? Anybody familiar with this issue?

 

One more thing, do you know where I can get a manual for this PD Prism Finder?

Is there an online pdf copy I can get somehwere? Your response is greatly

appreciated. Thanks.

[robert_rath]

Steve-I have a PRO II with a AE finder, I'm not 100% sure but I think the PD finder is for the RB, I think they work on the RZ, but not in aperture priority. Call Mamiya I think they will sell you the instructions for your PD finder.I got my AE finder from KEH.com.:-)

[steve_tenggala]

Well, that's kind of strange, because it says RZ67 in front of the prism body, just like the waist level or the AE finder. I know that RB has its own PD Finder (looks a little different), but it just puzzle me that I couldn't find any info or literature about this unie in Mamiya website.

[robert_rath]

Steve, take the prism off and see if it has the conectors, thats the only way that it has to comunicate with the camera body. I'm not real sure, but I think you will need a power source for that prism. I would get a AE prism, they work great.:-)

[steve_tenggala]

Robert,

 

the prism does have a connector pin underneath. It uses the body battery to do the metering. In fact, the A/S and the plus sign lights on everytime I press the reading button. I just wonder if it is supposed to be working that way since the reading never changes despite me aiming the lens at very bright and very dark condition. Also, if you can find this finder every now and then on eBay, but strangely I can't find any info about it on Mamiya website.

[robert_rath]

Steve, call Mamiya I'm sure they have a manual. I know because I called them not long ago when I had an RB. I would sell the PD finder and get the AE finder. I'm sure you could sell it on E-bay. Good luck with it.:-)