Hi Ralph,

I guess the truth is I wasn't really doing too much thinking at all before I posted - the idea just kinda' popped into my head and then spilled out onto the keyboard .

But..... yes, the idea was to use the shutter as a Packard style shutter. Then, (thinking while out while out shopping) I sorta' twigged to your thought about the "gate" size, and now.... I wonder if it's possible to put the shutter between the the elements.

If I have my lens theory right, the image flips R to L and top to bottom, with all the light passing thru' the three dimensional centre of the lens assembly. If the two dimensional centre of the shutter curtain could be put at the same place as the three dimensional centre of the light path, then the "gate" size shouldn't matter ??

It's likely not worth the effort - quite a bit of machining involved to do this.