Computer Graphics with Photoshop - Re: Retouching scratchy black and white scans

Author

Re: Retouching scratchy black and white scans

David Dyer-Bennet

2007-01-30, 9:21 am

Fat Sam wrote:
> photoguy_222@yahoo.com wrote:
>
> I may be over-simplifying things here, but did you scan the black and white
> ones in black and white mode?
> If you scan them with the exact same settings you used for the colour ones,
> wouldn't you get the same flaw free results?

No.

ICE works by doing a 4th scan pass in the infrared, and then essentially
interpolating into the blank spaces in that scan (caused by gunk on the
film, scratches, etc.). This only works because the dyes used in color
slides and negatives are all transparent in the infrared (except some of
the versions of cyan dye in some Kodachromes, which is why some
Kodachromes cause trouble). The silver grains in traditional B&W film
all block infrared, so the ICE system decides the entire image is
damaged, and has nothing to replace it from. (Dye-based B&W films like
Ilford XP2 work fine with ICE)

jeremy

2007-01-30, 9:21 am

"David Dyer-Bennet" <dd-b@dd-b.net> wrote in message
news:45bd0a3e$0$15008$8046368a@newsreader.iphouse.net...
> Fat Sam wrote:
>
> No.
>
> ICE works by doing a 4th scan pass in the infrared, and then essentially
> interpolating into the blank spaces in that scan (caused by gunk on the
> film, scratches, etc.). This only works because the dyes used in color
> slides and negatives are all transparent in the infrared (except some of
> the versions of cyan dye in some Kodachromes, which is why some
> Kodachromes cause trouble). The silver grains in traditional B&W film all
> block infrared, so the ICE system decides the entire image is damaged, and
> has nothing to replace it from. (Dye-based B&W films like Ilford XP2 work
> fine with ICE)
>

I recently saw what appears to be an improved version, "ICE4." It is
supposed to have better results with Kodachromes. I didn't notice if it was
purported to work with B&W. Some Nikon scanners are implementing it.

Johan W. Elzenga

2007-01-30, 9:21 am

jeremy <jeremy@nospam.com> wrote:

>
> I recently saw what appears to be an improved version, "ICE4." It is
> supposed to have better results with Kodachromes. I didn't notice if it was
> purported to work with B&W. Some Nikon scanners are implementing it.

ICE4 is a set of four functions, with things like color restauration and
grain control added to the Digital ICE dust and scratch removal. It
still doesn't work with Kodachrome AFAIK.

--
Johan W. Elzenga johan<<at>>johanfoto.nl
Editor / Photographer http://www.johanfoto.com

David Dyer-Bennet

2007-01-30, 9:21 am

Johan W. Elzenga wrote:
> jeremy <jeremy@nospam.com> wrote:
>
>
> ICE4 is a set of four functions, with things like color restauration and
> grain control added to the Digital ICE dust and scratch removal. It
> still doesn't work with Kodachrome AFAIK.

In fact, ICE has worked fine with Kodachrome back to the LS-2000 scanner
some years ago. It's not *guaranteed* to work with Kodachrome. And
according to a friend who's looked into it, the problem is with the cyan
dye used in some versions of Kodachrome, and then some pictures having a
very high density of that dye. But all the Kodachrome slides I've
tried on my LS-2000 and then my 5000ED have worked fine.

Fat Sam

2007-01-30, 9:21 am

David J. Littleboy wrote:
> "Fat Sam" <samandjanetknox@tessco.net> wrote:
>
> No. ICE doesn't work with most B&W films. ICE requires that the film
> be transparent to IR so it can find the (IR opaque or refracting)
> dust and scratches, but the silver remaining in B&W films is itself
> opaque to IR. You have to turn off ICE to scan B&W, at which point
> the dust and scratches show up in all their glory.

Aaaah.
I knew in the back of my mind that I was over-simplifying things.