Imperial shields

Mike Wong estimated that ISD's survived 30 minutes of battle with Mon Cal cruisers before losing shields. Heavy turbolasers are 1.5 megatons and medium ones are 15.6 kilotons.

http://www.youtube.com/watch?v=Oma9uPz9YYk

Here we have corvette pumping out 5 shots per second and ISD 2-3 per second. If we take ISD being able to fire 1 heavy turbolaser shot every 8 seconds (as it seems from movie - at around 6:28 at 6:36 we have same ISD firing one heavy shot), that translates in 9000 medium and 225 heavy shots - or 126.45 to 925.2 megatons for shields of Mon Calamari Star Cruiser. ISD's shields should be similar in strength or slightly stronger (maybe up to 150 to 1500 megatons), althought EU states that MonCal star cruisers had stronger shields, and ISD's better amor. So ending value would be 130 to 1000 megaton shields for ISD.

UPDATE: I have been warned that Mike Wong's estimation for 30-minute battle is wrong - time of entire battle is less than 30 minutes, and ISD's start losing shields long before that. I will have to re-watch movie later (I currently don't have enough time) and make my own estimates.

UPDATE 2: I have made estimates at my site.