Weird middle gray artifacts

[bonk]

I the attached image, I have some weird gray-ish branches in the trees and also down in the gras.
It is a scan made with Espon V850 Pro and Silverfast AI Studio 9.
I did not use a film holder but but the negatives (Agfa APX) directly on the glas. The negatives are lying pretty flat on the glas.
Any hint where this comes from? Other negatives of the same film do not have this "effect".
Did I make a mistake in the dials and sliders of Siverfast?

 

[Alan Edward Klein]

It looks like you're trying to pull data out of the black areas where there is none. Maybe the level (black point) is set incorrectly. I;m not familiar with Silverfast, but try changing the settings. Are your settings on auto or are you manually setting them?

 

[_T_]

Have you verified that the defect is not in the negative by looking at it with a loupe? It might be difficult to see.

I have seen an effect like this where only the shadows are inverted before but it was always caused by a problem during development.

If it was happening in the scanner software I would expect to find it in the curves tab. I can’t remember right now what silverfast calls it but it might be gradiation. Something like that.

The solution would be to reset that tab to it’s default state. If that doesn’t fix it you might as well reset everything to it’s default state and see if that helps. Close all the tabs you can and put all the values you can’t close back to default.

 

[Sharktooth]

This looks like you were using the "Digital ICE" setting when scanning. Unfortunately, this technology doesn't work properly for B&W film.

Digital ICE, or similar dust removal technologies, use an secondary infrared scan to detect dust. This only works for chromogenic dye images, like with color negative film. The silver in B&W film images blocks infrared, and creates weird blotches.

Make sure Digital ICE is turned OFF when scanning B&W negatives.

 

[koraks]

I the attached image, I have some weird gray-ish branches in the trees and also down in the gras.

I don't see it. If I boost contrast on the first example, I get this:

which looks like the texture of an actual tree, but that part of the film didn't get a lot of exposure, so there's not a lot of detail that can be extracted.

It looks like you're trying to pull data out of the black areas where there is none.

I agree.

@bonk your photo suggests that this is a classic problem with metering, where the camera's light meter was biased by the snow in the foreground, resulting in underexposure in the rest of the snow. It's a spin on the old "black cat in white snow" photograph - challenging to get right.

 

[TomR55]

SilverFast has a “feature” called AACO (or something similarly named). Its putative purpose is to enhance detail in shadow areas. Some time ago, I experimented with that feature and found that it did more damage in the shadow areas than good—creating artifacts not unlike what I think I am seeing in your samples. If you’re not using that feature than perhaps it’s an exposure or a black point setting error?