Examining resolution on the flatbed scanner with various degrees of focus adjustment.

I plan to run these same tests on a number of Epson flatbed scanners as well as testing digital cameras on a copy stand. As I finish the tests, I will update this post. I will be using a ThorLabs USAF 1951 resolution target for all tests. (See center area highlighted in the red box.)

The flatbed scanner tests being run first are 6 highly cropped 6400 dpi scans of the target. The uncropped scan with the red arrow is just for illustration and is a lower res scan.

The first cropped scan is at scan at the scanner’s glass level, the other 5 scans have been raised .225 mm, .45mm, 1mm, 2mm and 3mm above the scanner glass.

Yes, you can see the lines in the little box…if you use a microsope!

Here are the results of the first scanner…an ancient 11 year old Epson V500 scanner.

6400 dpi scan is at glass level using a Epson V500 scanner.

Resolution target was raised .225mm above the scanner glass using a Epson V500 scanner at 6400 dpi.

Resolution target was raised .45mm above the scanner glass using a Epson V500 scanner at 6400 dpi.

Resolution target was raised 1mm above the scanner glass using a Epson V500 scanner at 6400 dpi.

Resolution target was raised 2mm above the scanner glass using a Epson V500 scanner at 6400 dpi.

Resolution target was raised 3mm above the scanner glass using a Epson V500 scanner at 6400 dpi.

Personally, I don’t see things getting better the farther the target is moved off the scanner glass. But will have to do more tests.

To be continued…

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Daniel D. Teoli Jr. Archival Collection
Daniel D. Teoli Jr. Small Gauge Film Archive
Daniel D. Teoli Jr. Advertising Archive
Daniel D. Teoli Jr. VHS Video Archive
Daniel D. Teoli Jr. Audio Archive
Daniel D. Teoli Jr. Social Documentary Photography

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