Scanning for Black and White

Many of us who worked prior to the turn of the century, and even somewhat around that bend, shot with film. The following is for those who still work with film and combine film exposure and development with digital scanning and printing, to me a very good course to follow, and for those who have older film images they want to print or digitize. While I now photograph mostly with a digital camera, I also have lots of “legacy” film to work with, and recommend scanning and inkjet printing as the most sensible and creative means to realize those older images.

The main thing to keep in mind when scanning is to “do no harm.” There are various schools of thought on this, but my approach has always been to get as much image information out of the film as possible without doing any, or many corrective procedures beyond that which the scanner might offer. The scanner is there to pull information out of the film record and turn that information to digital form. Scanner software can enhance that information or add to it; use it to record, not overly enhance. You should also scan at the maximum optical resolution of the scanner, and not to work with “interpolated” resolution, that is, to not add to the information through algorithms. If the scanner you use does not create the amount of information you require for your prints—in other words, produces less resolution that you need for a particular image size—then get another scanner or have the images scanned by a pro lab.

Scanners vary greatly in their specs and capabilities, and new models come out periodically, so I will not recommend or follow a particular hardware and software here. While dedicated film scanners (strip and sheet) will yield better results, a new generation of flatbed film scanner (for reflective as well as transmissive material, i.e., film) has changed the thinking on the need for a dedicated film scanner for film scanning. My choice is to work with a dedicated film scanner for 35mm and I use a flatbed for medium format.

It is a fairly simple matter to convert any color image to black and white, so you can scan color slides to color (RGB) or to black and white (grayscale) data. Most scanner software shares similar settings. You start with choosing the type of film then put in how you want the scanner to handle the film. You can scan at 16-bit grayscale, which pulls much more information than an 8-bit scan or even in color, and then convert later in software to grayscale. You then put in the “output” size, which is final print size, and also the resolution, usually 300 dpi. The software calculates the rest. Keep in mind that if you are scanning solely for black and white, choosing 48-bit color increases file size substantially.

Many scanners offer presets of various sorts, which you should test to see if they help or hinder your work. These vary from presets for film profiles, such as various types of slide and color negative films, to tone curve and color cast renditions, which can affect black and white conversions.

The mantra is “do not harm”; don’t add contrast, try to fix every exposure flaw etc in scanning. Get all the information you can from the film and then work the problems later in software. If you keep the tonal richness and detail of the original in your scan you allow the most leeway later in your image interpretation, or best chance for an faithful reproduction of the scene. It’s the same gospel as that of camera exposure. Even slides that have begun to lost dye integrity over time can be “salvaged”for black and white printing.

8 Scanning Tips

1) When scanning color negatives or slides you can scan for color or black and white. It’s easy to convert to black and white later in image editing software.

2) Scan at the highest bit depth available.

3) Test the dust and scratch removal software in your scanner to see if and when it causes unsharpness. It can help save retouching time later (except on black and white negatives and Kodachrome slides, on which it usually does not work.)

4) Scan for the highest non-interpolated resolution you think will be necessary. Do not resample in the scanner software. Never exceed the scanner’s optical resolution.

5) DO NO HARM. Do not try to enhance contrast too much or fix contrast or exposure problems; save that for the image editing software.

6) Watch for highlights. If necessary, do lower contrast in the scan phase. You are collecting information, and if you do not record the information in the scan you will not have it to work with later.

7) Think big, but be reasonable. There is a limit to how big a print you can make from various size format film. Test to see the limits of your scanner and don’t expect to solve all your problems in the scanner phase of things.

8) Scan neutral, create in software later for expressiveness.

Photos and text copyright 2010 George Schaub: Scanning can help preserve even faded or dye challenged slide film. This old Ektachrome slide was undergoing a magenta shift, but scanning it for b&w printing allowed the image to be useful again, and a nice print resulted.