Guidelines for greyscale scans

The best place to get your sizing and resolution right is on the control dialogue of your scanning program as you are actually making the scans.

First decide what resolution you need. This will be dictated by the screen ruling of your final output. You should scan at 1.5 times the screen ruling e.g. for an 85 LPI screen, scan at 130DPI.

Next decide on your scaling as a percentage. This will usually vary on a pic by pic basis. A few minutes spent at the start of the job with a ruler and calculator (see tip box at right for an easy way) will save a lot of guesswork, wasted disk space and time waiting for printouts because you scanned at a resolution that was too high.

Once you have made your scans you will need to set the shadow and highlight dot levels. Your shadow dot should be no less than 30% for bromides and 15% for negs. The highlight dot no more than 90% for bromides and 95% for negs. Photoshop and PhotoPaint are commonly used to make these adjustments, but sometimes your scanning software can make them for you.

At this point you may also need to adjust gamma correction to enhance detail in the midtones - pay particular attention to the detail in people's faces if these are in your photo.

Finally make any enhancements that you require. Most photos look better with some sharpening as the scanning process tends to make them fuzzy.

If you need to retouch flaws in the original it is often best left to after sharpening and other adjustments are complete as the sharpening will often make what you are trying to hide stand out!

If you don't know up front what size your photos will need to be use a low res scan while you play with the layout, then measure and re-scan at the proper percentage and resolution.