From: Andre Fuhrmann (Andre.Fuhrmann@uni-konstanz.de)
Date: 05/08/01-09:53:18 AM Z
>Hi
>
>I've read some old journals on making pinholes, and they seem to suggest
>using brass or silver sheet. I've made a couple in very thin brass sheet,
>and now need to 'blacken' the inside edges of the pinhole. In the old
>journals (1900-ish) they suggested leaving the brass in a mixture of dilute
>hydrochloric acid and sodium thiosulphate. ...
I make pinholes from thin copper: it is softer than brass and cheaper
than silver. As to blackening I found it not really _that_ important
in practice. Yet I do it sometimes. My method is to use exhausted
fixer to coat the copper with silver and then blacken the silver with
selenium toner. Anything that oxidizes the silver should work too
(but in that case the silver may more easily flake off). I would
advise against using soot since this will almost certainly ruin the
edge of the hole. The smoothness of the edge is IMHO more important
than its possible reflectance.
Pinhole photography is a subject well-documented in the www. Start
your favourite search engine and you will end up knowing more about
it than you ever wanted to.
André
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