Originally posted by butangmucat Do I get advantages like finer grain?
通过我的 Nexus 6P 上的 Tapatalk发言
I haven't ever used Portra 800, but my experience with most C41 films when overexposed is that you get the appearance of finer grain, at the expense of resolution and tonal range.
If you're scanning your fillm, any underexposure tends to result in noisy shadows. Some overexposure will remedy the shadow noise issue and so will give the appearance of finer grain. With more overexposure you will get more density on the negative, plus the highlights will kinda hit a density/exposure ceiling but the shadows get pushed up further from the unexposed film base and closer to that highlight ceiling, so you end up with a shortened tonal range on the film. With the added density, the scanner will have more trouble "seeing" through the film which will result in a loss of fine detail.
As I said before, you're probably fine shooting Portra 800 at 400. My guess would be that the film will give best results in the 640-800 range.