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Re: filmscanners: cleaning neg's, sharpening
Just a couple of quick comments..
1. Cleaning neg's with water
Bear in mind that if you use anything but 'unexposed' distilled water as a
cleaning agent, you are in fact using carbonic acid..!
I used to work in a oceanographic lab, and while checking the pH levels of
a distilled water producer, I was surprised to discover how acidic the
'pure' water was. The resident chemist gently explained that H20, when
exposed to air, absorbs CO2 and degrades quite quickly to a carbonic acid
solution, of about pH 5.0-5.5 I think. (I'm flying by memory here - any
chemists on the list feel free to correct..)
Keep that in mind if considering water for cleaning fragile items!!
2. Sharpening
>Sharpening should be done before retouching the image, because sharpening
>causes many details to show up which have to be retouched.
I guess we are all different, but at the low levels of sharpening I use,
I've not encountered sharpening effects that needed retouching. I would
have thought that other types of re-touching, eg cloning/rubber-stamping
areas, is more likely to produce 'edges' that sharpening may pick up and
worsen. So I *always* sharpen last, if at all.
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