Im shooting with a konica hexar, and I developed and scanned the first rolls and all the picture were quite underexposed. I didnt realize that the hexar had a non ttl meter and I was using an R25a filter. How do I compensate the exposure. some say I should compensate by 3 stops so if I use iso 400 film I set the iso in camera to iso 100? Is that correct? It seems like a lot to me.