The more I learn about this the odder the set-up (as reported back to be seems),
from what I can tell shooting full app with an academy mask for hd1080 framing with a superTV lens is not a very standard approach. The focal length is 24mm but the problem is I get drastically different effects depending on the filmback I set to. Usually I am told we shot a 24mm lens full app. I set my lens to 24mm, I set my film back to full app and I am done.
I've now spoken to 2 guys at fries engineering and they are also a bit confused, apparently there is one guy there who can help but he's (of course) out of town.
It's definately a puzzle but the more I learn the more appriciation I get for DP's and all they need to deal with.
I really appriciate everyone who has taken the time to drop there insight here. Many thanks.