Wall warts; was: hams on classiccmp

[Tony Duell]

> 
> On 22/01/2009 22:39, Paul Koning wrote:
> 
> > Then there are fun details like this one: ethanol is a nice harmless
> > cleaning fluid for many things, including most plastics.  But it will
> > turn plexiglas matte.
> 
> And never use IPA to clean the focus screen in your SLR camera.  I had 
> to have a Pentax dismantled and the screen replaced after that one.

Thad depends on what the focussing screen is made of. Some of my cameras 
are old enough to have real ground-glass screens, which are not attacked 
by any common cleaning solvents. But the plastic ones used in more recent 
cameras are very easy to damage. Having just looked at a Spotmatic, I can 
confirm the focussing screen in that is plastic, and that it comes out 
upwards arter removing the top plate and pentaprism, so it's not trivial 
to replace.

-tony