What is this sinar part?

[brucep]

I bought a camera where the lens board had been modified with the addition of a back to front sinar lensboard.
This adapter which takes a lensboard both sides then allows the mounting of a lens.
The adapter has no evidence of any attachment holes, and although I assume it is part of a standard, I am not sure.

Can anyone tell me what it is, so I can try to get another as I would like to modify another camera to work the same way. I appreciate that I can swap it over, but I am going to leave it on the wrong camera at some point and ruin a day out.

Thanks
Bruce

[Tony Lakin]

I have never come across one nor have I heard of the existence of one, could it simply be a frame for connecting two sets of bellows? maybe too heavy for that and Sinar did make intermediate standards so maybe not

[Tin Can]

I use Horseman 4x5 frames to mount Sinar lens boards on both sides.

[jackpie]

You could use the frame from a parts Norma standard or a Norma auxiliary standard. They look similar to your photo. Or you could use a Sinar F or P frame. I can see this would work as a lensboard adapter for using Sinar boards or the Sinar Copal Shutter with other brands of cameras like Arcas or Linhof Kardans. Adapters to use Sinar boards are rare so I understand what you are trying to achieve.