Hi! Since mine has turned out pretty good, here's my method to obtain a nice visual effect for the scope!
All you need is a lens (I took mine from an old Polaroid camera), an old shiny cd-rom, a piece of red OHP film and a superfine marker.
1- cut out from the cd-rom a circle with the correct dimensions of the inside of your scope
2- cut out from the red OHP film a circle of the same size and draw on it the scope lines as you like. Be as precise as possible!
(This way you can try different scope styles without cutting out your entire cd collection )
3- assemble as shown:
The key is to put the right distance between the lens and the cd-rom+OHP, experiment till you find the right compromise!
Here's the result:
Hope you like it!
bye, Pablo
EDIT BY DAETRIN: updated title