Description of manual ISO when flash fire:

0.0EV 
Normal mode - ISO320, 1/30s
Twilightportrait - ISO400, 1/30s
Portrait mode - ISO250, 1/30s 
Document mode - ISO100, 1/30s 

-1.0EV 
Normal mode - ISO250, 1/50s
Twilightportrait - ISO320, 1/30s
Portrait mode - ISO200, 1/50s 
Document mode - ISO100, 1/250s

-2.0EV 
Normal mode - ISO160, 1/250s
Twilightportrait- ISO250, 1/200s
Portrait mode - ISO125, 1/250s
Document mode - ISO100, 1/500s

+1.0EV 
Normal mode - ISO400, 1/30s 
Twilightportrait - ISO400, 1/15s
Portrait mode - ISO320, 1/30s 
Document mode - ISO160, 1/30s

+2.0EV 
Normal mode - ISO400, 1/15s
Twilightportrait - ISO400, 1/10s
Portrait mode - ISO400, 1/30s 
Document mode - ISO250,1/25s


Note: To use different ISO setting and exposure time, change the exposure value, you will get it.