[URL]http://en.wikipedia.org/wiki/ProPhoto_RGB[/URL] from what I read ProPhoto RGB is the defacto RIMM now but this is a case I side with a film metric, negatives have long dynamic ranges to accommodate exposure latitude chromes depend on good exposure meters and lighting meters to get the scene I don't think digital cameras have the exposure latitude of negatives yet ROMM is better than RIMM for relative colorimetry (appearance) in most professional use cases because it has the practicality of proofing approvals,, soft or hard, being built into the workflow maybe use cases will evolve around RIMM and ERIMM