Help me fix my slide projector (please!)

Hi,

While I was fishing out a slide that had gotten stuck in my slide
projector (a Zeiss Ikon 350IR: similar to the Leica Pradovit range), a
piece of glass fell out from near the bulb.

Please see the diagram at the following web page

http://www.pc.rhbnc.ac.uk/mc/proj.html

The piece that fell out is labelled 'C' on the diagram. I have put it
back inside the projector but I can't tell which way round it should go:
should the curved surface be facing the front of the projector as shown
in the diagram, or should the straight surface be facing the front of
the projector? I have tried both ways and both seem to work but I would
like to know which is the correct way! I guess this piece of glass is
some kind of magnifying lens?

Many thanks!

Marco

 

Marco, light doesn't generally care which way it goes through
multi-element lenses. But it would be best to put it back like the
diagram shows, though I have not looked at the diagram.

Ken Cashion