Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Turn photo negative to positive image.
#2
Home scanners only do 24x36 negatives.

If you want to digitize the negative, the best solution is to take a photo of it with some back light. In the previous century this was complicated (had to find a back light of decent intensity and color temperature that doesn't burn the negative, so that was mostly taping the thing to a window on a cloudy day). But these says you just put the negative flat on a LED display (phone/tablet/laptop/monitor) on which you display a white area (you can insert a sheet of printer/paper as a dimmer/diffuser).

Ideally you do all this with a camera on a tripod (there are also cheap fixtures to transform a phone into some sort of scanner)(*), but if you do this hand-held you can use Gimp's perspective tool to compensate the shooting angle.

Once you have a negative you apply a reverse curve with Curves (ie, make a curves that goes from top left to bottom right) (using Color > Invert would be a first approximation but isn't too likely to be ideal). You can save the Curves setting to apply to further negatives.

(*) If you do this with a camera+tripod there is a trick with a mirror to ensure that the camera axis is perpendicular and centered.
Reply


Messages In This Thread
RE: Turn photo negative to positive image. - by Ofnuts - 02-10-2022, 05:51 AM

Forum Jump: