[renes]

BTW, the 150/4.5 Heliar lens was an optional lens on the 9x12cm Bergheils - mine has that. The bayonet flange should fit on that...

A while ago a group of us on the German large format forum (www.grossformatfotografie.de) had extra flanges made for both 6x9 and 9x12 Bergheils.

Ole,

Here are the two photos, one is Bergheil 6x9 fited with original Heliar 105m f/4.5 lens - you can see the crew mounting ring (which thighten the bayonet flange to the lens) and it goes just into the hole of the lensboard. The socond one is Bergheil 9x12 with Heliar 150mm f/4.5, the outer rear lens covers almost all the hole space and there is not enought free space (maybe 1mm) for the crew mounting ring...

The interior diameter of bayonet flange is 44mm, the mounting Heliar 150mm rear lens is 43mm... Far more, the Heliar 150mm shutter diameter is aprox. 79mm, but the lensobard is 73mm - so the lens does not lean on it. I do not know how it can work on your Begheil 9x12 with Heliar 150mm... you must probably have larger bayonet flange and larger hole in the lensobard.

Could you check it?