5 ms·

I printed the images onto A4 paper (held in front of a lamp). It's quite fiddly to get them to match. Very fine sub-mm accuracy needed.

• grenoire 9y ago
  Not only that, but both sources must be printed at the same aspect ratio and DPI.
• moondev 9y ago
  just drag the image on top of the other with your mouse
  • Luc 9y ago
    The point is that it's much harder with a hardcopy...