[wellman]

Hello, folks. This is my first post with you guys; I usually hang around the dgrin forums , and I was directed over here with this question...

I'm planning to put together a photobook (using Blurb, Picaboo, etc - haven't decided) of historical photos of my family's ancestry - basically anything my grandmother has in her attic. Step one of this process is scanning the prints in and doing a reasonable job of restoration.

So, here's my question... Given the fact that I have two purposes here (archival of the history and presentation of the final book), what DPI should I be scanning these originals to? I'd never be planning to to huge blowups of these prints, but at the same time, I want to preserve as much data as is reasonable.

My plan has been to scan at 1200dpi and sample down to 600 for archival (letting Photoshop do the resample as opposed to the scanner software to get better quality). Is this enough? Thanks!

-Greg Wellman

[mistermonday]

Wellman, welcome to Retouch Pro!
I suggest that you consider the maximum size you will ever want to print from you archived master file, and make sure your scan has enough pixel data to print that max size at 300 ppi.
So, for example, if your max size will be 8 x 12 inches, your image size should be 2400 x 3600 pixels. If you are scanning a 4 x 6 in photo, you will need to scan @ 600 ppi to achieve that resolution. If you are scanning a 35mm slide or negative (approx 1 x 1.5 in) you will need to scan at 2400 ppi to achieve that resolution.
More resolution is always better but if it is too high you will produce very large files. Assuming that you have a modern scanner, it likely can produce 16 bit data which means your files double in size again.
Your optimun situation would be to produce enough image pixels to achieve your 300 ppi reseolution. The data should be 16 bits. Store the archive unedited scan in an uncompressed format like psd or a tiff. Always work on a copy because most likely, some day you will want to do something different with a photo and you will wish you had the original raw data from the orig scan.
Good Luck,
Regards, Murray

[wellman]

Thanks, Murray. I only want to go through this once, so I'll default on the side of "too much data." I don't think I'd ever want to print more than 2x the original size on these - many are blurry as it is. However, maybe I'll go for keeping 900 or 1200 dpi in my archive just in case. Disk space is cheap, and I suppose time isnt.
Thanks again!