I am sure these techniques must exist, but most of us are trying to do the opposite, i.e. control our scans to diminish film grain as much as possible. Grain is one of the distinguishing features of many digital images that result from scans of film. Some film photographers are perfectly happy with grain and accept it as part of the film process, so long as it is not obtrusive, which it can be in some scans.
Much that can be done in scanning to minimize grain to the point where a film capture and digital capture image can look very similar.
In drum scanning grain is minimized by setting the aperture so that it is about equal to film grain, and then adjusting pitch (pixels per inch) so that it is slightly larger than the aperture. As one can tell by looking at the varying quality of drum scans from there is a lot of art in this that is learned from experience. Fluid mounting is also often used in drum scanning, and this also minimizes grain.
Grain can be minimized in scanning with flatbeds by several methods.
1) Fluid mount.
2) Scan at a resolution too low to capture film grain, and then rez up in Photoshop. This method has the disadvantage in that it wastes some of the resolution of the scanner.
3) Scan at a very high-interpolated resolution and then reduce the file size back to optical resolution in Photoshop. This is the method I use for scanning MF B&W negatives with an EverSmart Pro scanner. The exact procedure is as follows.
1. Scan at 8000 ppi in RGB in 8 bits. (The scanner will not allow 16 bit B&W saves).
2. In Photoshop change the Mode to 16 bit RGB.
3. Change the Mode to 16 bit grayscale.
4. Save this file as the Master.
5. Downsize as needed for the size print you want to make.
Attached are a couple of files that show the results of this method.
File 8000 was scanned at an interpolated resolution of 8000 ppi, and then downsized to 3175 ppi.
File 3175 was scanned at optical resolution of 3175 ppi. The area represents about .1" X .1" on the original TMY negative. At the crop size shown the entire image would be 135" X 165".
Grain is much smoother in File 8000, and detail is also better since grain size does not break up the image patterns. All scanner driver setting were the same for the two scans. No smoothing filters were used, and sharpening was set at default.
Sandy King
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