I have not managed to post much of anything to the blog this week -- between home life and work life I've been pretty busy. I will get some new scans completed this weekend, as well as some re-scans. Right now I have about 3 DVD+R discs' worth of completed, final scans that I'm satisified with, in high resolution. Some of these files are very large (200 MiB or more). I think the largest is around 400 MiB, which requires a pretty capable machine to open or edit.
I'm scanning them with a variety of settings, depending on the nature of the print. Black and white prints with decent contrast are generally getting scanned at 600 dots per inch, but some that are extremely sharp are getting scanned at 1200 dots per inch. All of the very oldest are getting the 1200 dots per inch treatment even if they are large. A small handful of prints are getting scanned at 2400 dots per inch. Three of these are tiny contact prints that are of the same size as the original negative, so I can recover a lot of detail if I scan it at a resolution closer to what one would normally use for a negative.
The relatively modern black and white prints with good contrast are getting scanned as 16-bit grayscale images. But the older prints, in sepia or cyanotype and often very faded or stained, I'm scanning as 48-bit color images, even though they aren't really full-color images. That sounds wasteful, but I've discovered that for many of the faded or stained prints, a cleaner image can be obtained by picking and choosing what RGB data is mixed down to gray. Sometimes stains are a particular color that differs from the photo tint itself, so using three color channels give me a better shot at removing the stains. Basically, this gives me more options to work with for later attempts at image restoration.
Image restoration plug-ins and tools seem to be a growth industry right now so I'm imagining that in a few years there will be tools that can do things with the high-resolution, high-color images I can't even think of yet.
These are the sets of files that I want to start shipping out to family members on gold DVD+R discs, together with index prints, as off-site backups of the Armstrong Collection. Gold DVD+R discs are a bit pricey so I have not purchased them yet, although I have made test backups of each group on conventional DVD+R discs.
These big files are the "master" scans that feed into Aperture. Most of them are just as they were saved by the scanning program, although I have rotated and cropped some of them, or stitched together multiple scans (in the case of prints that were too big to be scanned in one pass). There is no contrast or color correction, no de-skewing, and no touch-up for dirt removal, except what I could achieve by cleaning the prints. That means these aren't the best images for actually looking through the collection. For that, I'll need to distribute galleries of lower-resolution enhanced images.