Bluish spots on old photos

[pcather]

Often in old photos I have this problem with bluish spots. If you zoom in on the color photo you can see them. They are actually all over the picture but you can only see them in the very dark areas, like her eyes and shadows of her hair. They are mainly in the blue channel attached as well (middle pic). Compare with green channel which only shows a little of it. (far right pic)

One: is there a was to minimize these when I'm scanning?
Two: Does anyone have a good way to minimize these after the scanning?

Thanks,
Pamela

[Senet]

What this is basically is artifacting. It's noise brought on by the scanner. It's also why you see it the most in the blue channel since that is typically known as the noise channel.

As for your other question that becomes more of a balance between reducing the noise and maintaining sharpness and detail. Your best bet when you do anything with these is do the work in print size of the final. There are times when you are working on an image bigger than it will be used then you zoom down to print size and it's negated and hardly visible. A few things you can try is to do a filter for reduce noise and remove the strength and color noise to 0 then go to the advanced tab and play with the strength and such on the individual channels you see the noise in. Secondly you can also convert the image to lab color and gaussian blur the a and b channels to help you reduce the noise there.

Keep in mind that the more you are reducing it the more you are removing the initial integrity of the image as well so loss of sharpness and detail can occur. It's up to you to draw the line of acceptability.

[pcather]

If this is a scanning problem, is there any way to prevent this when scanning?

[Senet]

What kind of scanner are you using to scan these in?

[lurch]

They look like silvering to me. Silvering is deterioration in the print itself, and while there are scanning techniques to minimize it, it has nothing to do with the scanner. There are also techniques to alleviate it in post-processing. I suggest you do a forum search on"silvering".