Voltage:  9 or 12 Volts
    Horizontal Frequency:  15.734 kHz
    Vertical Frequency:  59.94 Hz
    Field of View: 90 degrees
    Resolution:  400 TV lines
Pinhole lenses are commonly used due to their small size.  They can be put in a small camera case of 1/2 inch thick!
Pinhole lenses are sensitive to low-light conditions and one lens could cost about $500. (Yost 208)  (http://www.interlog.com/~microvid/058.htm)
This is a fiber optic lens.  As you can see, it is like a long tube.  It can be used by drilling a hole in a wall, snaking it through a key hole, or in many other hard-to-reach places. (Yost 208)  It can also be used as a recording device when screwed onto a camcorder adaptor.  The standard length is a meter, but there are some 3 meter models available. (Spy Shop)

This is the size of the smaller end.  The diameter is 2 mm and it captures a field of view of 45 degrees and sees images near or far. It can do this because it has the ability to bend light.  That is how you are able to see, although it is bent.  The Spy Shop sells the 1 meter models for $580, the 2 meter models for $780, and the 3 meter models for $830.  (Spy Shop)
both fiber optic scope images borrowed from "http://www.spy.th.com/opticsb.html"

This segment of the page was last updated May 12, 1999