In consumer flatbed scanners, the Green channel is the sharpest of the 3 channels. To get the sharpest scan of a B&W negative, we scan in 48-bit color, but use only the Green channel. We save the data from that channel, as a 16-bit Grayscale image, and toss away the blue and red data.
Click to See Comparison
Above is a small detail section taken from a scan of the 4x5 B&W negative. Click on the image to see the 3 channels raw and moderately sharpened. It's pretty obvious: the Green channel contains the clearest data. This is true for CCD scanners in general, especially for consumer-grade models like the Epsons.
Don't take my word for it. You can easily find out for yourself. Here's how:
Epson:
Even though we are scanning a B&W negative, we set Image Type to 48-Bit Color. This will give us a color image, where each of the 3 color channels has a full 16 bits of data.
VueScan:
There are several ways to do this with Epson and VueScan software, but for artistic purposes, it's best to preview the image - and make tonal adjustments - in Black and White, rather than Black and Green.
After scanning, we use the Channel Mixer to remove the Red and Blue channels. Set Red to 0%, set Green to 100%, and set Blue to 0%. Be sure to select the Monochrome option.
After removing the Red and Blue channels, convert the image to 16-bit Grayscale, using the menu items Image > Mode > Grayscale.
Now save the image. All done !
We want to get an image directly from the scanner, which comes as close as possible to the final print. We want to avoid performing lots of digital adjustments in our image editing tool, like Photoshop. The image above illustrates the "analog" quality of an image that has been properly exposed, developed by inspection, and scanned in a simple, straightforward manner. Minimal manipulation in Photoshop was required.
To see more "analog" images like this, click here here
To learn more about this approach, click here for more scanning tips.