|
Modified
webcam installed on trinocular port. |
Webcam
Modifications...The first order of business is to remove the
lens. Why? The CCD array is tiny, 1/3". This, in itself,
guarantees a high power at the plane of the CCD array. Introducing
an eyepiece as a relay lens serves only to increase the magnification
of the image. The view through the visual eyepieces of the microscope
then becomes considerably less magnified than the view captured
on the CCD array. Also, you will experience the same issues that
people connecting digital cameras to microscopes experience. If
the entrance pupil of the webcam's lens is larger than the exit
pupil of the microscope's eyepiece, then the images will be partial
circles in a square format. I don't particularly care for the
looks of these images. Directly projecting the microscope's image
from the objective lens onto the CCD array avoids over-magnification
of the image and results in a completely filled, rectangular image
frame. With my webcam, the field of view through the CCD array
appears to be somewhat equivalent to a visual field of view when
using 15x eyepieces in the binocular viewing head.
Removing
the lens from the Logitech Quick Cam® Zoom is very easy.
A single screw holds together the two halves of the camera body.
Remove the screw and gently pry apart the two halves of the camera
body. There is a rubber-like focusing ring that grips the lens
assembly. Gently pry this from the camera body and slide it off
the front lens assembly. Turn the front lens assembly counterclockwise
until it separates from the rear half of the lens assembly. Behind
the front lens assembly lies the infrared filter at the bottom
of the rear lens assembly. For reasons I will discuss later, this
assembly needs to be removed also. Carefully remove the electronics
board from the camera body. On the backside of the board are two,
small Phillips-head screws. Remove these screws to remove the
rear lens assembly and expose the CCD array. Caution!!
Do not touch the protective cover over the CCD array!! Avoid getting
dust or any other material on the protective cover!!
On
the electronics board you will also see a fairly large, green
LED. This LED must be covered with black tape so that green light
does not fall on the CCD array. Carefully cut a small piece of
black electrician's tape and completely cover the green LED. Now,
fit the electronics board back into the proper slots in the camera
body and snap the two camera body halves back together. This is
a good time to eliminate the mounting base that came with the
camera, too. The mounting base just adds unnecessary weight and
bulk to the camera. The hole it leaves in the camera body can
be covered with tape to prevent dust from getting into the camera
body. Replace the screw that holds the camera body halves together
and we'll be ready to make an "adapter" to fit the microscope.
In
an ideal and elegant world one could have a machinist make custom
bushings and mounts to attach the camera to a microscope's trinocular
port or to the second eyepiece on a binocular viewing head. Let's
get real and
practical, however! A simple, but adequate, adapter can be made
witha black Kodak plastic film canister, a hot-glue
gun, and a roll of masking tape! Cheap and effective, but definitely
not elegant! LOL The black (only the black!) plastic film
canisters in which Kodak packages a roll of 35 mm film has a flanged
end that fits perfectly over the opening in the webcam where the
lens used to sit. I cut the film canister just a little more than
half length and used a hot-glue gun to glue the canister to the
webcam. Don't
be dumb, like I was the first time I did this, and glue over the
seam between the two camera body halves!! LOL It
makes it quite difficult to reopen the camera body in the future
if you run the hot-glue over the seam! LOL After gluing the film
canister to the camera body, simply wrap 1" wide masking
tape around the microscope's trinocular port or around the second
eyepiece tube on a binocular viewing head to the proper diameter
to make a snug slip-fit of the film canister over the tape. Voile´,
instant camera adapter!
|