Text pages scanned at 300dpi
Text with Drawings at 600dpi black and white
Schematics at 600dpi black and white
Text with photos at 600dpi grayscale with contrast adjusted
Schematics, board overlays that have color notes at 600dpi 256 colors
The other set is done in resolutions that vary depending on individual page content, but are never higher than needed to produce a useable quickly navigable file that will do the job without consuming more time and resources than are needed.
The large resolution file is bookmarked, hyperlinked, and features both the Chapter-Page Numbering System and the Sequential Numbering System.