I just got back from the lab some nice Provia 400 shots and am quite happy with them. I never used this film before as I am just beginning my experiments with slide film. My images with Provia 100 were not that great and it seems all to be due to poor shutter speeds. WIth the 400 speed film, my shutter speeds are higher and the sharpness is all there. I do not see much grain at all in the 400 speed film so that was a nice surprise. The color is great and the lack of grain really gives these images some punch. So I'm wondering two things. One, can Provia 400 be pushed to 800 with good results? Is the grain still OK? Since 400 has such low grain, I am wondering if there is any serious advantage at all to Provia 100? Is the grain really that much lower if you can get the good shutter speeds? I might just forget about Provia 100 since the 400 looks so good. Thanks for reading!