Fujinon 400mm T lens on lens board

[peter lagus]

It appears that there are two ways to mount the Fujinon 400mmm T lens to a mounting board. Looking at pictures on epay, I see some boards mounted immediately to the rear of the Copal shutter. Others use a Horseman(?) board that mounts on the rear of the lens itself. Why are these mountings different?
How would I remove the Horseman(?) board to use a more convectional mounting at the rear of the shutter?

I am confused.

Pete

[peter lagus]

I have made a couple of photos to explain my problem in more detail. The question I have is how do I remove the lensboard/tail piece that the lens in mounted on? I don't want to force anything since it is not obvious to me how the lensboad/tail piece actually detaches from the lens. Please help.
Pete

[peter lagus]

Sorry for the strange position of the attachments. I don't know why they came out like this.

Pete

[Ken Lee]

Here are 3 photos which show a 400 T properly mounted on a Technika board.

The 400T is mounted just like other large format lenses: the shutter is mounted onto the board and the front/rear cells are screwed into the shutter.

[peter lagus]

Ken:

Thanks for the pictures. I was pretty sure that was how the board should be mounted. My question is more basic. If you note the lens board in my photos is mounted on the rear edge of the lens. The board itself is rigidly attached to a cylinder that extends to the Copal shutter. My question is "How do I get that board off?" I don't want to damage anything in the process. The lensboard/cylinder will rotate but it does no unscrew from the lens. So I am still confused.

Thanks again

Pete

[cowanw]

Perhaps the back lens screws off from the board or perhaps the shutter and the sleeve is just a spacer..

[Gem Singer]

Looks like a "top hat" extension lens board that's screwed on too tight.

Former owner probably needed more bellows extension.

Lens board and extension will unscrew from the shutter if you screw around with it for a while.

[peter lagus]

Thanks for the suggestions. The top hat was screwed on very tightly and had very little clearance at the back. There was only about 1/16 of an inch clearance to hold onto when trying to unscrew the rear lens.

I finally did get the rear lens to unscrew. I was able to attach a conventional Copal 1 lens board. This was a real learning experience.

Pete