Quote Originally Posted by mingaun View Post
Thank you all for your helpful comments.

Keith in your example of severe overexposure, you said your negatives was almost black. In normal circumstances to salvage this you need to do some special printing procedures isn't it? But if you just scan it on the computer I presume it would be almost black with almost zero detail right? My understanding is that the latitude advantage of black and white film is manipulated in the traditional developing and printing process but not in the scanner procedure.
The latitude of b&w neg film is helpful in both workflows.

In the traditional workflow, you just "print through" the thick neg, i.e. you do a longer exposure to the paper. You will also need to do a contrast adjustment, e.g. print to multigrade paper and fiddle with contrast and perhaps do split grade printing. This is because all the info you want is bunched up in a narrow range of optical densities.

In the scan workflow, the optical density of the thickest (=most overexposed) negative is well within what most scanners can handle. A good flatbed can manage close to DMax 4 - about as dense as Velvia can get. Even a wildly overexposed b&w neg reaches nowhere near that optical density. So what happens is you scan the neg and find that the tones are all bunched up, but then you 'auto-level' the tones to try and get the right contrast. It is very easy. Actually easier than traditional route, I daresay... but not necessarily better Anyway that is a topic for DPUG.

So... either way, the latitude of film real shines.

There are, of course, consequences of overexposure. But the point is that you can overexpose a neg film quite severely and still get a usable image. And even if you don't overexpose wholesale, another point is that little specular highlights will be held in detail, e.g. highlights on jewelry or a wedding dress, chrome on a car, reflections on water, etc...