The director wants the "Private Ryan" shutter angle, the DP wants to shoot Chris-Doyle framerates. And you are supposed to do the calculations? Let take away some of the steam.

Simply enter the new shutter angle and the shooting fps. Also, add the base values for each, and will display both the exposure time and the compensation needed in relation to the exposure you would get with the base values.

In our example the show is shot at 180° with 24 fps, but the next shot is on 100° with 20 fps. To get the same exposure you would have to open up 2/3rds of a stop.