Canon FS4000US Advice Sought

  • Thread starter Thread starter John
  • Start date Start date
J

John

1. Does it make any difference altering histogram etc before scanning? Does
this affect the way the scanner scans a negative/slide or are all the
'changes' done afterwards i.e. the slide can be scanned at normal settings
and edited afterwards.

2. Using FARE (dust and scratch remover) sometimes generates strange
patterns on very dark sections of a slide - why? Is this a fault? Scratches
are removed but the pattern is unacceptable.

3. Scanner resolves grain on film - is it possible to minimise this effect
and get more real detail from the picture. Should grain be showing up when
scanning at 4000 dpi? Will sharpening make it look worse?
 
John said:
1. Does it make any difference altering histogram etc before scanning? Does
this affect the way the scanner scans a negative/slide or are all the
'changes' done afterwards i.e. the slide can be scanned at normal settings
and edited afterwards.
Click to expand...

I honestly don't know. 95% of the time, I just go with the default values.
2. Using FARE (dust and scratch remover) sometimes generates strange
patterns on very dark sections of a slide - why? Is this a fault? Scratches
are removed but the pattern is unacceptable.
Click to expand...

This can occur with Kodachrome and B/W films that have silver in the
emulsion. The silver messes with the IR cleaning channel.
3. Scanner resolves grain on film - is it possible to minimise this effect
and get more real detail from the picture. Should grain be showing up when
scanning at 4000 dpi? Will sharpening make it look worse?
Click to expand...

Yes, sharpening doesn't help! Try running the scanner under Vuescan.
The stock Canon drivers apparently apply sharpening routines that cannot
be disabled.

I think most people run http://www.neatimage.com/ or similar noise
reduction software on the images as they come off the scanner. See
http://www.michaelalmond.com/Articles/noise.htm

-Greg
 
Make your corrections before scanning. If you do it afterwards you will get
a gappy histogram where you are missing certain luminance values. It does
change the way the film is scanned, at least with the software I am familiar
with.

The Canon is known to have some problems with noise in the dark areas. I
don't know why this would increase using FARE. You are talking about
scanning non-Kodachrome films, right?

At 4000 ppi the grain is resolved, but there is also the problem of "grain
aliasing" in which the pixel size can interfere with the grain size and
cause "false grain". You can try something like Digital GEM to lessen this
effect, at the cost of some perceived sharpness, I believe.

Toby
 
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