Problems (?) with Canon FS4000US and FARE

[John]

I've just acquired one of these scanners and have just noticed a weird
effect using FARE (dust and scratch removal). Scans without are fine, but
when using FARE and zooming in on shadowy areas I can see a feint pattern of
fine lines in pattern of horizontal, vertical and at 45 degrees (diamond
shape). These seem to occur in very dark areas only. I don't know if its a
faulty scanner or a common problem (what causes it?) FARE works well
removing dust etc but I don't know if the pattern will be a problem when the
pictures are printed or if and how I can eliminate them.

 

[Bruce Graham]

I've just acquired one of these scanners and have just noticed a weird
effect using FARE (dust and scratch removal). Scans without are fine, but
when using FARE and zooming in on shadowy areas I can see a feint pattern of
fine lines in pattern of horizontal, vertical and at 45 degrees (diamond
shape). These seem to occur in very dark areas only. I don't know if its a
faulty scanner or a common problem (what causes it?) FARE works well
removing dust etc but I don't know if the pattern will be a problem when the
pictures are printed or if and how I can eliminate them.

If you are looking at very high magnification (like 400%) that sounds
like where the software is filling in the dust/scratches.

Are you using the Canon software or Vuescan? (sometimes one works better
than another for image repair, but mostly folks here are fans of
Vuescan).

 

[Greg Campbell]

I've just acquired one of these scanners and have just noticed a weird
effect using FARE (dust and scratch removal). Scans without are fine, but
when using FARE and zooming in on shadowy areas I can see a feint pattern of
fine lines in pattern of horizontal, vertical and at 45 degrees (diamond
shape). These seem to occur in very dark areas only. I don't know if its a
faulty scanner or a common problem (what causes it?) FARE works well
removing dust etc but I don't know if the pattern will be a problem when the
pictures are printed or if and how I can eliminate them.

Are you scanning Kodachrome by chance? Silver based emulsions can cause
FARE to go haywire, producing ugly shadow artifacts. AIUI, the
scanner's IR channel is confused by the dense silver, mistaking it for
dirt, and causing FARE to 'fix' those areas.

-Greg

 

[John]

Its Agfachrome (Agfa CS system) so I don't know if thats a problem. The
scanner seems to work fine normally without FARE. The 'artifacts' (if that
they be) manifest in very dark shadow areas - not completely black and do
not show in areas of normal brightness. I don't know if changing the
software will improve but I assumed if the scanner uses infra red somehow
the problem will be generated within the scanner and cannot be improved. I
wonder if it is the film if I can use software to get rid of the blemishes
rather than FARE.

 

[Bruce Graham]

Its Agfachrome (Agfa CS system) so I don't know if thats a problem. The
scanner seems to work fine normally without FARE. The 'artifacts' (if that
they be) manifest in very dark shadow areas - not completely black and do
not show in areas of normal brightness. I don't know if changing the
software will improve but I assumed if the scanner uses infra red somehow
the problem will be generated within the scanner and cannot be improved. I
wonder if it is the film if I can use software to get rid of the blemishes
rather than FARE.

If you are using Vuescan you get manual control of the IR exposure. Try
increasing the IR exposure to max. It may be that the IR lamp is not
bright enough to shine thru the shadows with the exposure setting you
have, so it would think the shadow is one big dirt patch and squiggle
over it to "correct" it.

 

[Don]

I've just acquired one of these scanners and have just noticed a weird
effect using FARE (dust and scratch removal). Scans without are fine, but
when using FARE and zooming in on shadowy areas I can see a feint pattern of
fine lines in pattern of horizontal, vertical and at 45 degrees (diamond
shape). These seem to occur in very dark areas only. I don't know if its a
faulty scanner or a common problem (what causes it?) FARE works well
removing dust etc but I don't know if the pattern will be a problem when the
pictures are printed or if and how I can eliminate them.

I recently posted a similar problem (no replies). In my case the
regular pattern is composed of 15 x 10 pixel rectangles in the bright
areas, normally invisible but revealed during processing. I don't use
FARE, and everything else is turned off (no NCM, no ICE...) Anyway,
instead of explaining it all again here's my original post:

--- cut ---

I just discovered something really odd! Nikon LS-30, here, but it may
be NikonScan 3.1 that's the culprit. It goes like this...

In order to reveal the shadows detail I often need to scan to cause
clipping in highlights. I noticed weird histogram values at the high
end e.g. a relatively low count for 255, then a significant spike at
254, and then the count falls off gradually as it should. This was
consistent across a number of different films (slides).

I would've expected a clipping spike at 255, not at 254, but I
contributed that inconsistency to noise.

However, applying Levels to such an image with input set from 253 to
255 a very fine - 1 pixel wide - regular mesh is revealed, with each
element 15 pixels wide and 10 pixels high!?!? This only occurs in the
areas of the image which are clipped. The same effect can be observed
by applying the Equalize command.

Does anybody have an explanation for this? I'm particularly puzzled by
the regular and consistent nature of this mesh.

Don.

 

[Jon D.]

I've just acquired one of these scanners and have just noticed a weird
effect using FARE (dust and scratch removal). Scans without are fine, but
when using FARE and zooming in on shadowy areas I can see a feint pattern of
fine lines in pattern of horizontal, vertical and at 45 degrees (diamond
shape). These seem to occur in very dark areas only. I don't know if its a
faulty scanner or a common problem (what causes it?) FARE works well
removing dust etc but I don't know if the pattern will be a problem when the
pictures are printed or if and how I can eliminate them.

Hi,

I'm afraid I can't help - I've had this problem with Reala, I think.
Does what you're seeing look anything like this....
http://l21bjnd.users.btopenworld.com/fs4000.html

They only seem to occur in light areas, but these will be dark in the negative.

Cheers,
Jon.