Mamiya 6 Flash Sync

[mrmekon]

I just picked up a new toy, a Mamiya Six folder (the Mamiya Six IV, I believe). It included a "synchro-flash" with it, and I'm trying to get it working with that, but I fail to understand how the flash connects. It has a Seikosha-Rapid shutter.

Here's the front. That red dot is the front of what I believe to be the flash sync terminal. I think it's a non-functioning PC terminal?

Here's the terminal from the back. A PC cable fits on it, but it's very snug.

With the cover removed, I found the mechanism. When the shutter is cocked, the connection between the frame and a center conductor is broken.

When the shutter fires, the connection is made:

Here's the thing: the center conductor on the PC cable isn't touching anything, so no connection is ever made. Is a piece missing/broken, or is this not a PC terminal, or am I just doing something dumb?

The synchro-flash is odd itself. It has two screw sockets. I buzzed them out with a multimeter. One connects to the case, the other connects to the positive prong at the base of the flash bulb. It seems like something is supposed to screw into each of them, and then connect to the camera somehow. It only came with one screw-in cable, and that cable is a single conductor that terminates in something similar to a mini-plug.

Very odd. Anyone know what the deal is? Thanks!

 

[StrangestStranger]

I just picked up a new toy, a Mamiya Six folder (the Mamiya Six IV, I believe). It included a "synchro-flash" with it, and I'm trying to get it working with that, but I fail to understand how the flash connects. It has a Seikosha-Rapid shutter.

Here's the front. That red dot is the front of what I believe to be the flash sync terminal. I think it's a non-functioning PC terminal?

Here's the terminal from the back. A PC cable fits on it, but it's very snug.

With the cover removed, I found the mechanism. When the shutter is cocked, the connection between the frame and a center conductor is broken.

When the shutter fires, the connection is made:

Here's the thing: the center conductor on the PC cable isn't touching anything, so no connection is ever made. Is a piece missing/broken, or is this not a PC terminal, or am I just doing something dumb?

The synchro-flash is odd itself. It has two screw sockets. I buzzed them out with a multimeter. One connects to the case, the other connects to the positive prong at the base of the flash bulb. It seems like something is supposed to screw into each of them, and then connect to the camera somehow. It only came with one screw-in cable, and that cable is a single conductor that terminates in something similar to a mini-plug.

Very odd. Anyone know what the deal is? Thanks!

Hello mrmekon, have you ever figured out the flash with your Mamiya 6? I have a similar Mamiya 6 that I'm trying to figure out how to connect to a more modern flash. On the back of my shutter, behind the red dot, exists a single post. A PC connector will not connect to it because the post in the PC connector interferes. I'm curious if you figured something out.

 

[Donald Qualls]

There were apparently multiple versions of this camera. Mine (dual format, no frame counter, Zuiko lens) has a standard PC connector. The one above is very much not; I think it's something Japanese.

 

[reddesert]

I have had one of those. It's not for a standard PC cable. IIRC, the circuit is between the center conductor and the housing above the lens. There is a metal leaf inside the silver housing at top that closes as the shutter is fired. I think it's actually the cocking lever flying back that pushes the leaf to close the circuit. If you have a multimeter you may be able to verify continuity between these points as the shutter fires. You would need to make a 2-wire connector that pushed onto the center conductor and also contacted the housing. It's not any standard flash connector I've seen.

 

[StrangestStranger]

I have had one of those. It's not for a standard PC cable. IIRC, the circuit is between the center conductor and the housing above the lens. There is a metal leaf inside the silver housing at top that closes as the shutter is fired. I think it's actually the cocking lever flying back that pushes the leaf to close the circuit. If you have a multimeter you may be able to verify continuity between these points as the shutter fires. You would need to make a 2-wire connector that pushed onto the center conductor and also contacted the housing. It's not any standard flash connector I've seen.

Thanks, that is very helpful. i'll check with the multimeter, and if that is the case i think i can fashion something with hacking an old pc sync cord.

 

[JPD]

What is the purpose of the big red dot?

 

[StrangestStranger]

What is the purpose of the big red dot?

In my example, it serves no purpose, just aesthetics.

 

[reddesert]

What is the purpose of the big red dot?

I don't know but I wondered if the original flash connector clamped over it somehow to make the second connection.

 

[JPD]

The big "red dot" could be flipped up on earlier models for unknown reasons: http://camera-wiki.org/wiki/Mamiya_Six_I

I tried to find a manual, but had no luck.