What sort of things one should keep in mind before buying a Scanner?
a.) Prints: This is easy; just get the cheapest flatbed scanner, and if for good quality, just pick up the cheapest EPSON Printer. Even the cheapest flatbeds offer FOUR times the resolution that one requires.
b.) 35mm Slides and/or B/W Negatives: It is better to go in for a real film scanner if the need arises.
c.) Medium Format Transparencies and/or B/W Negatives: The best buy is $3,000 film scanner like Minolta Multi PRO or a good flatbed like the EPSON 4990.
d.) 4×5″ Film: 4 x 5 desktop film scanners are out there today in the market. It is better to buy a good flatbed like the EPSON 4990 or Microtek 1800f.
Keep the images and file sizes down, with any scanner resolution. In fact, it is better to turn down the resolution of any scanner to keep the resolution low enough to make emailing possible, and to keep the image small enough to fit on a computer screen. Honestly, if internet and email is the need of the hour then a flatbed scanner is fine.
Printing on paper is more difficult. If the print is 8 x 10″ or bigger getting the highest resolution a dedicated film scanner is possible. Flatbed scanners are poor for printing from 35mm film, although great for scanning one-hour lab prints.