No use backlighting for slides?

When backlighting a standard flatbed as though for trying to copy slides
or negatives, I assume there is no point in this as the scan head in the
bed underneath needs to sync the light coming from above somehow as into
red, green and blue bursts that would only come from a plug-in head and
not a light source held above?

I ask this as I have a Canon CanoScan FB330P flatbed scanner and I have
just tested a colour negative using a backlit source separated by a
white plastic card diffuser and the result is a black and white copy.

So, I assume it's get rid of this unit which has done well for some
years and get one with a plug-in attachment that sits on top, time?

Mine is not your usual scan method (for slides or prints) as I have
short cut strips of Super 8mm film which are only of value historically
and not worth splicing together, so I need to scan a strip in and chop
it later in a paint package.

In article ,
says...
When backlighting a standard flatbed as though for trying to copy slides
or negatives, I assume there is no point in this as the scan head in the
bed underneath needs to sync the light coming from above somehow as into
red, green and blue bursts that would only come from a plug-in head and
not a light source held above?

I ask this as I have a Canon CanoScan FB330P flatbed scanner and I have
just tested a colour negative using a backlit source separated by a
white plastic card diffuser and the result is a black and white copy.

So, I assume it's get rid of this unit which has done well for some
years and get one with a plug-in attachment that sits on top, time?

Mine is not your usual scan method (for slides or prints) as I have
short cut strips of Super 8mm film which are only of value historically
and not worth splicing together, so I need to scan a strip in and chop
it later in a paint package.

Obviously, your method could never be optimal.
However, I don't know why it came out b/w, with no semblence of color.
Should have at least looked "orangeish".

However you light, your scanning software must know how to invert the
neg to positive. That sounds like you could just do it after the fact in
any imaging program, BUT no; the software must compensate for the heavy
orange mask of the negative film. Trying to do this on your own after
the fact is a PITA; though there are some guides as to how to do it by
sampling the mask, subtracting that, etc, it will still never do as well
as letting a competent scanner interface software manage that for you.

There are also lots of "home brew" lighting methods for top lighting a
flat bed, but as you've pretty much already found, none are as good as
one designed for the scanner that is designed to scan film.

Also also, you'll get much more action at comp.periphs.scanners. This is
pretty dead group here.

MM

MoiMoi said the following on 30/01/2008 00:42:
In article ,
says...
When backlighting a standard flatbed as though for trying to copy slides
or negatives, I assume there is no point in this as the scan head in the
bed underneath needs to sync the light coming from above somehow as into
red, green and blue bursts that would only come from a plug-in head and
not a light source held above?


Obviously, your method could never be optimal.
However, I don't know why it came out b/w, with no semblence of color.
Should have at least looked "orangeish".

There are also lots of "home brew" lighting methods for top lighting a
flat bed, but as you've pretty much already found, none are as good as
one designed for the scanner that is designed to scan film.

Also also, you'll get much more action at comp.periphs.scanners. This is
pretty dead group here.

MM

Yes, it puzzled me too! I'd initially did a big run some months back
with some old WWII negatives of my father's that were here for a short
while so didn't think about colour problems. Then I try a colour
negative, do a 'negative' in Paint Shop Pro and it's black and white.
Even the source looks black and white so that gave me the clue that
something was wrong.

Many thanks for that.