Scanning slides

  • Thread starter Thread starter il barbi
  • Start date Start date
I

il barbi

I wonder whether there can be a problem when scanning
slides, that is the fact they don't lay just on the glass
but are some 0,8 mm. higher due to the plastic frame. I
noticed that my 35 mm slides are never plane but always more
or less curved, so I guess there can be a focus problem when
scanning them. How can the scan mechanism adjust to the
slide and keep the bending into account? Are there scanners
allowing the slide lay on the scanning glass? Anyway this
would not guarantee they stay perfectly plane, something
transparent would also be needed above them and pressing
them
thank you
il barbi
 
I wonder whether there can be a problem when scanning
slides, that is the fact they don't lay just on the glass
but are some 0,8 mm. higher due to the plastic frame. I
noticed that my 35 mm slides are never plane but always more
or less curved, so I guess there can be a focus problem when
scanning them. How can the scan mechanism adjust to the
slide and keep the bending into account? Are there scanners
allowing the slide lay on the scanning glass? Anyway this
would not guarantee they stay perfectly plane, something
transparent would also be needed above them and pressing
them
thank you
il barbi
Click to expand...

In general, flatbed scanners have a large enough depth of field so
that it doesn't matter if the film is elevated slightly. Good film
scanners have autofocus that focuses on the emulson side of the film,
so it's taken care of there also. Badly curved film will sometimes
cause a focus problem, though, with either type of scanner.
Charlie Hoffpauir
http://freepages.genealogy.rootsweb.com/~charlieh/
 
il barbi said:
I wonder whether there can be a problem when scanning
slides, that is the fact they don't lay just on the glass
but are some 0,8 mm. higher due to the plastic frame. I
noticed that my 35 mm slides are never plane but always more
or less curved, so I guess there can be a focus problem when
scanning them. How can the scan mechanism adjust to the
slide and keep the bending into account? Are there scanners
allowing the slide lay on the scanning glass? Anyway this
would not guarantee they stay perfectly plane, something
transparent would also be needed above them and pressing
them
Click to expand...

Flatbed scanners generally don't have an adjustable mechanism to take
account of either the exact position of the slide above the glass or the
curvature of the film. Most dedicated slide scanners do have a focus
adjustment which takes account of the position, but even they have no
adjustment that takes account of the film curvature.

In both cases the depth of field of the scanner optics is the only means
of accommodating the variable position of the slide surface.
 
Back
Top