Hi everyone,
I hope you can help me make sense of some mysterious residue I’m noticing on my scanner glass—and some surprising results from a small experiment I did.
The Issue
When digitizing photos with my Epson V850 Pro, I’ve noticed a very fine layer of residue appearing on the scanner glass when I lift my photos. It seems like it’s coming off the photos themselves like surface smudges (they are 6x4 prints from the 70s, 80s and 90s). It’s extremely difficult to see the residue, but when I bend over the scanner with a strong headlamp, I can spot it after removing many of my photos. Neither my girlfriend or me can see the residue when we look at the scanner from the side or without the direct light on it.
I’ve tried wiping the scanner glass with a microfiber cloth, but it feels like I’m just spreading the residue around instead of removing it, I still see some patterns from the residue —kind of like when you clean your glasses with only a microfiber cloth and without using lens cleaner, you see some patterns. The smudges don’t fully disappear, and I’m left with small streaks or marks on the glass.
Key Questions
For those of you who clean your scanners due to dirt or residue buildup with glasscleaner or alochol:
My Experiment
To test whether residue actually affects scan quality, I deliberately put fingerprints on one side of the scanner glass and compared a scan in 2400 DPI between the clean and dirty sides. The fingerprints were thick and greasy—and I guess more visible than the subtle residue left by my photos after I’ve been rubbing a microfiber cloth on it (the spots from the picture). Surprisingly, I couldn’t see any difference between the scan from the clean side and the one from the fingerprint-covered side. My test scan was of a printed photo in 600DPI and I could clearly zoom in on the ink dots on both images and it didn’t seem blurry. Which I find very weird.
I did read something about the depth of field being so narrow on a scanner that it might not pick up greasy fingers on the glass unlike a camera lens on which you need to clean it with glasscleaner or lenscleaner if you see residue/grease.
What to do?
The reason this is important to me is that my girlfriend is very careful with her dear family photos and doesn’t feel comfortable placing them on a scanner that has been cleaned with alcohol or glass cleaner because she’s afraid and feels like that would leave marks/patterns on the scanner glass kind of like when you wash a window with window cleaner you see marks/patterns/stripes from the liquid in the shapes you dragged the cloth you used. And she’s afraid that those patterns will be visible on the scans and if the scan will seem more blurry.
Some photographers using the same flatbed scanner tells us they are only using a microfiber cloth to remove dirt and not any liquid, but we find it very weird if the scan of the pictures won't become blurry, when the glass has patterns from residue. We’re trying to balance keeping the scanner clean while also protecting the photos.
Our main concerns are:
Has anyone else experienced this? Could it be related to the residue, or might it be something else?
Thanks so much in advance for any insights!
I hope you can help me make sense of some mysterious residue I’m noticing on my scanner glass—and some surprising results from a small experiment I did.
The Issue
When digitizing photos with my Epson V850 Pro, I’ve noticed a very fine layer of residue appearing on the scanner glass when I lift my photos. It seems like it’s coming off the photos themselves like surface smudges (they are 6x4 prints from the 70s, 80s and 90s). It’s extremely difficult to see the residue, but when I bend over the scanner with a strong headlamp, I can spot it after removing many of my photos. Neither my girlfriend or me can see the residue when we look at the scanner from the side or without the direct light on it.
I’ve tried wiping the scanner glass with a microfiber cloth, but it feels like I’m just spreading the residue around instead of removing it, I still see some patterns from the residue —kind of like when you clean your glasses with only a microfiber cloth and without using lens cleaner, you see some patterns. The smudges don’t fully disappear, and I’m left with small streaks or marks on the glass.
Key Questions
For those of you who clean your scanners due to dirt or residue buildup with glasscleaner or alochol:
- Do you clean it because you’ve noticed that leftover residue makes future scans blurry?
- Or is it mainly to prevent the next physical photos from picking up dirt from the scanner glass?
- Or is the only reason you clean it that you see residue with your eyes and just by principal wants to remove it?
My Experiment
To test whether residue actually affects scan quality, I deliberately put fingerprints on one side of the scanner glass and compared a scan in 2400 DPI between the clean and dirty sides. The fingerprints were thick and greasy—and I guess more visible than the subtle residue left by my photos after I’ve been rubbing a microfiber cloth on it (the spots from the picture). Surprisingly, I couldn’t see any difference between the scan from the clean side and the one from the fingerprint-covered side. My test scan was of a printed photo in 600DPI and I could clearly zoom in on the ink dots on both images and it didn’t seem blurry. Which I find very weird.
I did read something about the depth of field being so narrow on a scanner that it might not pick up greasy fingers on the glass unlike a camera lens on which you need to clean it with glasscleaner or lenscleaner if you see residue/grease.
What to do?
The reason this is important to me is that my girlfriend is very careful with her dear family photos and doesn’t feel comfortable placing them on a scanner that has been cleaned with alcohol or glass cleaner because she’s afraid and feels like that would leave marks/patterns on the scanner glass kind of like when you wash a window with window cleaner you see marks/patterns/stripes from the liquid in the shapes you dragged the cloth you used. And she’s afraid that those patterns will be visible on the scans and if the scan will seem more blurry.
Some photographers using the same flatbed scanner tells us they are only using a microfiber cloth to remove dirt and not any liquid, but we find it very weird if the scan of the pictures won't become blurry, when the glass has patterns from residue. We’re trying to balance keeping the scanner clean while also protecting the photos.
Our main concerns are:
- Are we damaging future photos by placing them on a scanner with spread-out residue from the picture before?
- Should we expect the scans to become more and more blurry over time due to buildup if we only use a microfiber cloth, even though we didn’t see a difference in our test?
- If residue is a problem, what’s the best way to clean it without using harsh chemicals?
Has anyone else experienced this? Could it be related to the residue, or might it be something else?
Thanks so much in advance for any insights!
