thank you.
this means i have to adjust something while shooting?
for example shooting indoor with iso 640 and tilt to a window and press the iso button to go to iso 160?
Before shooting set you exp value for indoor, then use the exposure preset feature (present in nightly) to save those setting by pressing SET or INFO (depends on how you enabled it in ML menu), now set exp value to what is needed for the window and press SET/INFO again to savev tose settings too and switch back to the first "indoor" values.
No with gradual exposure on record the indoor scene, when moving to the window press SET, your expo value will change to what is needed for the window and gradual exposure will make the change smooth instead of immediate.