Constructing a Biocam

6 Feb 07:  This 15x biocam was constructed from a cheap USB digital camera and a magnifier known as a "jeweler's loupe".  There was sufficient flat surface on the front of the camera to glue the loupe directly to the front using a flexible adhesive called Liquid Nails.  After attaching the loupe, the assembly was affixed to a cardboard backer (two layers of corrugated cardboard were laminated at 90 degrees for rigidity.

7 Feb 07:  Balsa wood walls were glued on all 4 sides of the camera assembly, making a rigid box as shown. below.

7 Feb 07 (contd):   Now we must test the actual focal length.  If the distance from the Biocam to the subject is not correct, all the viewer will see are fuzzy shadows with - we hope - several light blobs cavorting across the field of view.  This length can be tested by making stacks of any uniformly shaped object you have in quantity (in my case, US 25 cent pieces).  I discovered that a nominal 7/16 inch distance between the box and the subject was called for - for this particular Biocam.  When the aquarium arrives, it's glass thickness will be measured and a tentative setback - from camera to subject will be chosen.  At this point, I think a focal length just on the inside of the glass will be my goal.  Here is a picture of the rusty lid of Ecosphere Alpha, snapped during testing.