Hello. I have experience working in a darkroom. Granted most my experience is with 35mm. I recently started shooting 120mm. I would like to be able to print 6x 6. I know you need a 75 or 80 mm enlarger lens to do so. My question is what is required to switch the lens out to a higher mm? I've never done this. Do I need a lens board plus the lens? or a lens mount? Do all Omega use the same type of lens mount? I also have a Rollie 6x 7 enlarger that is medium format 6x 7. The supplies for Rollie enlargers seem limited though? If anyone can help me understand how all this works I would be thankful.