Scanning Guidelines

Be sure you have the most original version of the item available. In particular, learn to recognize copy prints produced in the lab so that we can scan the negative the print was produced from.

These are basic guidelines for typical scans. There will always be exceptions.

• 300 DPI
• approx 3000-4000 pixels on the longer side
• include the edges of the print
• 8 bit grayscale and 24 bit RGB
• TIFF

Always, always, always, check the histogram of the image. This will tell you if you have captured all the image detail or not. It doesn't matter so much that an original scan looks tonally exactly like the original as long as you know all the information is there. As a general rule, scan it just a little flat looking as it is better to add contrast than reduce contrast.

If you're using a camera or film scanner, always check the file at 100% to make sure it's in focus. Edges of the photo and dust are the only things you can check reliably. Grain is not always visible.

When you save a file, remember that we use a master/working system. This means that the original scan, called the "master" is saved with very little alteration, and then all changes are made to a copy of that file, called a "working" file. This way, if you really mess something up, you can go back to the master file, create another copy, and work on that instead of having to rescan or reshoot. The edits that are permitted to files that are saved as master files are: cropping, rotating, and inverting (if the original is a negative). All other edits should be performed on working files.

When possible, include a gray scale with color items. Regular b/w prints and negs don't need this, but color does so that later if any color correction needs to be done, we know what neutral gray looked like.

When to do something different from the basic guidelines:

• Scan in 16 bit mode if the image is badly faded. This captures about 64,000 shades of gray instead of 256, making it easier to stretch the very narrow tonal range of faded photos.
• Scan larger than 4000 pixels if it's a map, panorama, 8x10 neg, or if you will be printing larger than 11x14 and the original has information worth it.
• If you're shooting trays of slides for powerpoint, go for 1000 pixels, 100 dpi. No sense in throwing around big files if they're not needed. If they want JPEGS for powerpoint, don't bother with TIFFs.
• Scan b/w negatives as transparencies if you're using a film scanner. For some reason, scanner software does not simply invert the image, it also performs tonal adjustments which are often destructive. Color negs are already messed up tonally due to the colored film base so scan them as negatives and let the scanner try to figure them out.

September 15, 2004