wrote:

Since we've got a good discussion going on light traps, I'll try to
describe the one I am working on based on a pringles can. I clean out
the can, and save the top to make a baffle. I cut off the bottom (but
save it to put back on later). I do this to make inserting the lining
and cone easier. I am using a sheet of stickybacked artificial black
felt from a craft store (Michaels in my case). I first line the inside
of the can with a rectangle of the felt. Then I cut a cone out of the
remainder of felt and glue it to the bottom of the can. I then glue and
tape the bottom back on the can. I paint the underside of the top of
the can flat black. I glue a piece of my whitest card stock to the top
surface of the top, with rubber cement. I then cut a one inch square
in the top, and blacken the edge of the cutout with a black magic
marker, and replace it on top of can. The white card gives me a white
reference.

The first one I made was okay, but the workmanship was lacking, from
too many cut and try operations. I will be photographing the building
of the second one, with thoughts of sending the manuscript to one of
the photo magazines.


Why put white card stock at the entrance to your light trap?
The white card will scatter light into your field of view
(inside the lens), limiting your dynamic range. Of course,
that system scattering limiting dynamic range might be what
you want, but that would limit isolating the sensor
characteristics for example.

Roger