Science Buddies: "Ask an Expert"

I am building a copper telescopic kaleidoscope and have limited space for the mirror system (I tested a 20mm L, 3 sided pyramid 10mm x 10mm x 12mm ). The focal length is 95mm & compacts to 35mm. Do I even need a mirror system if I do one or more of the following: 1) use a small prism inside 2) use a faceted cabochon or round lead crystal at the end similar to a teleidoscope 3) give a high polish to the inside of the piece and use felt or something else to prevent surface scratches when extending and retracting, in tandem with a clear crystal orb 4) spray the inside of the piece with mirror paint? This is due on the 14th and I have read about mirrors extensively to try and find a solution but to no avail. Thank you for your help!

Hello yolo_lilo_loli,

I'm not an expert on optics or kaleidoscope design so maybe one of the experts on the forum can provide some more specific advice.

I assume that the space limitation that you have is the length of the mirror system. If this is the case, it seems to me that your first three ideas may have the most promise. Another possibility might be to use a reflective prism to project an image from a shorter mirror system. This kind of “ghost image” is described at the following link.

http://www.instructables.com/id/Reflective-Prism/

I hope this helps and good luck with your kaleidoscope design. Please ask again if you have more questions.

A. Norman