Getting a good digital image of an old photo is a bit of an art. Here are my recommendations.
1. Use the scanner to scan, not to tweak
For starters, if you really want a good result, separate this into two processes: (a) scanning the photo, and (b) tweaking the scanned image. Specifically:
- Don't try to make the scanner "improve" the image, by adding sharpen, contrast, color or other filters. Just scan it.
- Plan to use a photo-manipulation software application, like Photoshop, to do the work of tweaking the scanned image.
Yes, this means you need to have an imaging application like Photoshop. But you really do need that, if you want good digitals of old photos. Scanner settings just don't work well on old photos, in my experience.
In fact, I receive a lot of scans of interesting old USN photos, from all over the world, and unfortunately, most of them aren't very good scans, so they are of greatly diminished utility. There are two typical reasons: the person "fixed" the scan, by applying sharpen and contrast filters, or the person scanned at a low resolution.
On the other hand, if you send me a scan as described below, even if it looks washed out or faded to you, I bet I can make it look a lot better in Photoshop than if you fiddle with the scanner settings to try to improve it.
2. Plan to scan the photos at high resolution, in an uncompressed format.
"Resolution" is a matter of "dots per inch," or "dpi." This means, literally, how many dots per inch the scanner will record. More dots per inch = more fine detail is captured. Fewer dots per inch = less detail is captured.
An "uncompressed format" is an image type like TIFF (.tif), which contains all the data the scanner picked up. A "compressed" image, like JPG (.jpg) takes the data from the scanner and reduces it, so the file size is smaller and the picture looks okay, but really there is much less detail.
For images in a web site, the typical resolution is 72 dpi. This is the highest resolution the typical monitor is capable of displaying. So for a web site, a 300 dpi image won't look any better than a 72 dpi image. This is why people make 72 dpi JPG images for web sites.
But wait... If you want to look at the image on your computer or print it, higher resolution makes a HUGE difference. For on-screen viewing, you can "zoom in" on the photo, if the scan is high-res., and see fine detail that you can't even see in the original photo with the naked eye, in some cases. Literally, you can pick up the facial features on some person way in the distance, in some of these old silver-nitrate prints.
For printing, 72 dpi simply isn't the standard. It's not nearly good enough to make a decent print. Typical recommendations for printing copies are to scan at 300 dpi for documents, and even higher for photos if you want to make a blow-up.
3. Always scan in color, even with black and white photos
The toning in old photos isn't just nice looking. Those subtle shades of sepia, and the various imperfections on the surface of the print - flecks of red or blue, or whatever other artifacts there may be - carry a lot of useful image data. When you scan in grayscale, you take away all that data. The blue mark becomes a black mark; the red mark is a smudgy gray mark, and the fiber or texture of the paper is flattened into the image.
The result is much less clarity, a flat-looking scan of the photo. And not only are the artifacts flattened into the image, but now you can't fix them in Photoshop, or some other image application, because you can't tell if that gray blot is a red pen mark, or if it's defect on the negative, or if it's really a part of the actual scene.
Always scan in color, even if you plan to make a black-and-white print. You can convert it to grayscale later on, if you really want to; but if you scan in grayscale, that's the end of the story. If you want to see the color detail later on, you'll have to re-scan it.
For documents: Scan in color, no filters, 300 dpi, as tiff images.
For photos: Scan in color, no filters, 600 dpi to 2400 dpi*, as tiff images.
* 2400 dpi will make a huge, almost unreasonably huge, file -- say, 150 megs. I use this sparingly, for cases where there is some interesting fine detail I want to bring out. Normally I scan at 600 dpi, or if it's an exceptional photo, 1200 dpi.
Note: If you are planning to scan images to submit to The Subchaser Archives:
- File size is no object. the Subchaser Archives has essentially unlimited access to digital storage space. (Really. If you want to send me a terabyte of data, that's fine.)
- Email is fine, for sending scans, but there may be limits on your end or mine, for attachment sizes.
- You can always burn the files on to a CD or DVD and mail them.
- Or, if you're willing to try something new, I can walk you through a couple of instructions for sending files directly to the server, using FTP.
- For details, email me