Just started using Gimp after loosing use of old PS program and am trying to enlarge a 35mm B/W negative that was scanned in from a 600 dpi Canon. I know, it's a cheapie but that's all I have.
Have not been able (so far) to figure out the 'canvas size' and 'image size' in order to enlarge it to at least 4" x 6", 5" x 7" or 8" x 10".
Also having trouble adjusting levels/curves/etc. to get the image looking better.
Thank you in advance and I feel sure I'll be back with more questions.
For the negative, you start with a "negative curve" (top left to bottom right) in Curves. A slight S shape increase contrast:
Thanks for your reply.
May not have been too clear in my post. Did my attachment come through? I scanned it in, opened it with Gimp, inverted the image and played around with curves, levels, etc. to make it not so blotchy. Not too successful. The negatives are pretty old so I'm not sure if that may be the problem or not. I found a link for scanning with a flattop that said: place on scanner, cover with sheet of white paper, place bright light (desk lamp), scan at highest resolution (600). The only addition I added is a glass pane over the negative to flatten it. Put that directly on the negative and paper on top with bright light. Is there a better way?
After that I tried to resize it for printing and got really confused. What are the steps for resizing? Canvas first? Image first? Print size first? Or, is it even necessary to do any of that?
For the negative, you start with a "negative curve" (top left to bottom right) in Curves. A slight S shape increase contrast:
Thanks for your reply.
May not have been too clear in my post. Did my attachment come through? I scanned it in, opened it with Gimp, inverted the image and played around with curves, levels, etc. to make it not so blotchy. Not too successful. The negatives are pretty old so I'm not sure if that may be the problem or not. I found a link for scanning with a flattop that said: place on scanner, cover with sheet of white paper, place bright light (desk lamp), scan at highest resolution (600). The only addition I added is a glass pane over the negative to flatten it. Put that directly on the negative and paper on top with bright light. Is there a better way?
After that I tried to resize it for printing and got really confused. What are the steps for resizing? Canvas first? Image first? Print size first? Or, is it even necessary to do any of that?
Thanks again!
No, your attachment didn't come through. Looks like you uploaded the file, added the link in the post, and then removed the file.
For the size, it all depends on the size in pixels that you get initially, and the print size you need. You can upscale the picture to get more pixels, but these will be blurry pixels, not much better that the upscale you get implicitly if the print driver needs to stretch you image.
For the negative, you start with a "negative curve" (top left to bottom right) in Curves. A slight S shape increase contrast:
Thanks for your reply.
May not have been too clear in my post. Did my attachment come through? I scanned it in, opened it with Gimp, inverted the image and played around with curves, levels, etc. to make it not so blotchy. Not too successful. The negatives are pretty old so I'm not sure if that may be the problem or not. I found a link for scanning with a flattop that said: place on scanner, cover with sheet of white paper, place bright light (desk lamp), scan at highest resolution (600). The only addition I added is a glass pane over the negative to flatten it. Put that directly on the negative and paper on top with bright light. Is there a better way?
After that I tried to resize it for printing and got really confused. What are the steps for resizing? Canvas first? Image first? Print size first? Or, is it even necessary to do any of that?
Thanks again!
No, your attachment didn't come through. Looks like you uploaded the file, added the link in the post, and then removed the file.
For the size, it all depends on the size in pixels that you get initially, and the print size you need. You can upscale the picture to get more pixels, but these will be blurry pixels, not much better that the upscale you get implicitly if the print driver needs to stretch you image.
Thanks. I have to leave for awhile and will check back. Trying again with the attachment.
I would make more useful comments and suggestions with the negative...
Don't be surprised by grain. Film grain was a reality, especially with any film of 100ISO or more. And if you scan at 600PPI, and then see it "dot for dot" on your display(*) (which is probably around 150PPI) everything is 4X bigger, so the small grains are visible splotches.
So, don't expect a silver bullet. You have to apply Curves carefully to maximize contrast but not falling where this increases the contrast in the noise, and then definitely need a second step to reduce the grain
(02-13-2022, 10:13 PM)Ofnuts Wrote: I would make more useful comments and suggestions with the negative...
Don't be surprised by grain. Film grain was a reality, especially with any film of 100ISO or more. And if you scan at 600PPI, and then see it "dot for dot" on your display(*) (which is probably around 150PPI) everything is 4X bigger, so the small grains are visible splotches.
So, don't expect a silver bullet. You have to apply Curves carefully to maximize contrast but not falling where this increases the contrast in the noise, and then definitely need a second step to reduce the grain
(*) See the link on image size in my earlier post
I didn't save the negative scan. I'll rescan it in the morning and send it to you.
Did the procedure I mentions above seem like a correct one or is there a better way?
02-14-2022, 12:50 AM (This post was last modified: 02-14-2022, 12:52 AM by Ofnuts.)
My phone camera (4000x2250) at close range will fit a 5cm (about two inches) of subject in the 2250 pixels, so as a scanner is it about double the resolution of your scanner (1100PPI).
02-14-2022, 04:48 PM (This post was last modified: 02-14-2022, 04:50 PM by nova.)
(02-14-2022, 12:50 AM)Ofnuts Wrote: My phone camera (4000x2250) at close range will fit a 5cm (about two inches) of subject in the 2250 pixels, so as a scanner is it about double the resolution of your scanner (1100PPI).
Back again.
I don't own a smart phone. Only a dumb phone (flip). I do own a DSLR and tablet so I'll try your suggestion. Below is the negative just scanned on my cheap Canon printer.
I opened it in Gimp and have not been able to make the curves effect reverse. Keeps dropping out when it reached the midway point. Obviously I'm doing something wrong but not sure what.
Tribulations of a newbie. (Tri-X film may be the reason for so much grain)
