Hello Georg,
I assume from the above that you don't want to link by "position".
You can unlink the images in the stack 1, 2 etc in the "Optimizer" tab.
In the "Expert" interface, after setting up your stacks, go to "Optimize:
Geometric -> Custom parameters" which will provide the "Optimizer" tab.
Open the Optimizer tab, and for Stack 1, right mouse click on the bold
underlined 0 for "yaw" and choose "unlink". This should unlink all
positional parameters. You may have to also do this for any additional
stacks.
Hope this is what you want. Please follow up if I have misunderstood your
question.
Cheers,
--
Regards,
Terry Duell