Originally posted by mer I just want the exact picture I would take ( same FOV and DOF ) with my DSLR and my 55/1.2 as I would with my 35mm film camera.
I would think the best you could do is a much crappier version of the exact picture - whatever lens element(s) you add to collect the wider field of view and cram it into the center of the 55mm lens is bound to degrade IQ something fierce. Certainly does with the samples I've seen (I was looking into wide adapters a while ago trying to find a cheap/small/light way to add a wide angle to my kit).
Anyhow, I'm not sure if you're just thinking of this as a thought experiment, in which case, by all means, go ahead.
But without knowing any better, I'm sort of guessing you might be new to the world of DSLR's and are assuming this would be a commonplace thing to do - that many people would be going about using adapters to get their lenses to work the same on both formats. That's just not the case. Basically, that would be like a cowboy kid turning 16, getting a new car for his birthday, then trying to figure out if there is an adapter to mount the saddle from his horse to the driver's seat of his car, or to get the car to run on hay*.
No, people normally just adjust to the fact that the two systems work differently.
[ *note: it has become my goal to work a car analogy into my posts as often as possible :-) ]