I needed Provia 400X but didn't have any. All I had was Provia 100F. My son's birthday party was in two days, so no time to order from B&H and pay reasonable shipping costs. So I did the next best thing. I shot Provia 100F at ISO 320 and had the lab push two stops. Read about it here. Note that the blog post is written for someone who may not be familiar with some of the terminology we use, such as pushing and pulling film. I tried to make it an easy read. I linked to it for two reasons: I don't feel like copying and pasting the same content here. There's not much info here about pushing Provia 100F two stops. Lots of info about 400X two stops, but not 100F.