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Re: Grain aliasing: do some neg films suffer less than others?



Alan Rew schrieb:
 
> Having acquired my new Nikon Coolscan IV ED (i.e. LS40), which I use for
> scanning negs, I am now seeing grain aliasing artifacts more clearly
> than with my old Canoscan FS 2710.

Hi, Alan,

this is somewhat natural. The Nikon has sharper optics, plus a
collimated LED light source, which both tend to increase grain aliasing
(and image sharpness). I had a LS-30 before my LS-40, and even that was
quite a jump as to both scan detail *and* grain aliasing.

> I've tried using the Nikon Scan GEM software, but to my eyes this
> produces either (a) an unnaturally smooth appearance or (b) strange
> artifacts that look like small wiggly lines. With GEM set to maximum (4)
> the image looks too soft with loss of detail; with Gem set to 1 there
> are still visible grain artifacts. Settings in between are no better.

Nikon Scan 3.x, in my opinion, has degraded a lot in comparison to 2.5.
If you intend to keep on using Nikon's software, try to change the ICE
rather than the GEM settings. ICE affects grain as well but does so in a
more subtle way than GEM. BTW, carefully check the histogram of your
negative scans - Nikon Scan 3.x has a mean tendency of clipping shadows
which usually shows itself in a rather abrupt slope at the histogram's
left side. Earlier versions (not working with the LS-40) had a "prescan
mode" control that would completely avoid the clipped shadows if set to
"lo-cont neutral" rather than "auto" - unfortunately, Nikon removed that
control in later versions, making Nikon Scan almost useless for my
negative scans.

> So... I was wondering if switching film brands would make a beneficial
> difference.
> 
> Previously I've used Fujicolor Superia, ASA 100 or 200.

If you're using these two, I strongly doubt switching to another film
would solve your problem. Superia 100 certainly is some of the finest
grained stuff around, and the improvement when using Reala will most
likely be marginal.

> Alternatively, is this purely dependent on the resolution of the
> particular film scanner used? My Nikon scans at 2900 dpi, the Canon at
> 2720 dpi (I think).

It is optics rather than resolution - the Nikon LS-40 is sharper than
anything I have used so far, including Minolta Scan Elite II and Nikon
LS-30. If the ICE/GEM juggling as mentioned above does not satisfy your
needs, there is only one final solution which actually is the one I am
using right now:

Go to http://www.hamrick.com and get yourself a copy of "Vuescan", Ed
Hamrick's well known scanning interface for different types of film
scanners (one software fits all scanners :-)). As to your problem, two
settings (apart from that negative has to be chosen as film type) are
essential: "Infrared clean" -> "medium", "grain reduction" -> "light".
Scan one of your negatives and look if the overall appearance of that
scan is closer to what you have in mind, at least as to the grain issue.
If yes, you'll have to acquaint with the numerous controls of Vuescan to
get the colors about right (the main goal of Vuescan is to produce "raw"
scans with a maximum of image information in them; those usually need a
bit more of post-scan color correction). If you're through this - allow
one or two days of scanning frustration and lots of beer and coffee for
it - you most likely won't touch Nikon's crappy user interface ever
again.

BTW, if you're running Windoze (as me), you might be able to use my
.ini-files for Vuescan, one for slides and negs each, where all those
settings are stored. Tell me and I'll e-mail them to you.

The link in my signature shows where my LS-40 scans can be found (only
the newer ones are LS-40 stuff; check each individual page for what the
photo was scanned with).

Hope this helps a bit,

Greets -

Ralf

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