Thank you all and PE.

Stephen , Could you please describe your thoughts little bit more ? You are saying Autochrome screen is not RGB , In my mind whatever this screen ever called , it can be copied from the original with a film , positively or negatively.

When it comes to register the screen film on to main film or paper can be done easily. I register two meter size emulsion transfer films less than 10 seconds with hundreth of a milimeter precision and I did may be 2000 of them.

But Stephen is talking about dispersion , this can be happen in thickness of glass plate but may be this can be replicated to put screen copy to one side of a glass and epoxy there and bw , negative , positive , color , whatever original you want to get , could be put to the other side.

See my other unanswered thread below third or forth of this thread.

Umut