Fixed Portrait Shoot

ISO 100

A:10

SP:1/15

 ISO 400

A:20
SP:1/160

 ISO 800

A:22
SP:1/250

 ISO1600

A:22
SP:1/500

ISO3200

Aperture: 25

Shutter Speed: 1/640

The best ISO setting would be 400. 

The next best ISO setting would be 800.

I would say kind of, by changing the aperture and shutter speed to get equivalent exposures for the  best photo.

I learn that you have to discover the setting by your self and make sure that they correct for the job, and that you have to know the area you are in to get the right settings.