>>2940207Well for one thing it's so that you have a general idea what your final image will look like with the settings you're at once graded (which is also nice if the director/clients are looking at the monitor, which is always). If you're exposing for, say 1600, it's nice to say how the various light values will fall in the final image.
Technically yes, with RED you can change ISO in post, but the image will be affected to some extent depending on what compression ratio you're shooting at with the Redcode, as the image here shows. If you're shooting 3:1 compression ratio, fuck it you have basically all the possible information anyway, exposing 'correctly' is just a way to save time in post. But if you're shooting 5:1 - 9:1 which is what most people will shoot so as not to have ridiculous file sizes, something's gotta give, that information will get compressed somewhere. Putting the EI where you need it to be tells the camera to save more information in the highlights and not worry about the shadows so much; the dynamic range always stays the same, it just shifts a bit to where you need it to be so it doesn't throw the important information out the window.
