Sinar Mystery Coupling Frame

[alan_b]

Hi, long time lurker here...

Can anyone shed some light on this rear coupling frame? It's missing the heavy plate at the bottom which holds the ground-glass back/bellows/lensboard in place. You can see the front coupling frame which is what I'm familiar with as a typical P-series part. The metal cover plate on the mystery frame is too light to securely hold a gg-back securely in place. The hex rod clamp is also different than I've seen before.

Another question, I believe this camera has an 8x10 rear bearer. What is the knob on the left side with the folding lever?

Thanks!
Alan

[Greg]

Could the frame missing the heavy plate be off of an Auxiliary standard that was made only to support bellows? Just a thought...

[alan_b]

Thanks - sounds reasonable to me. I'd only seen photos of the multi-purpose standard with the heavier plate - never seen one in real life.

[asf]

The knob with the folded lever is a swing lock (yes it's an 8x10 rear carrier)

[alan_b]

Thanks Guys.

I may have figured out the frame. I found a copy of the P instruction manual from 1971 which shows this style of frame. Maybe just an early version that was improved later.