Consumer
Grade Components
Consumer
cameras are mass produced for a broad, forgiving
market—the snapshot shooter
or the amateur photographer. Because of this, the quality
control checks are not very stringent when it comes to
assuring lack of defects in manufacturing. Critical quality
issues are all graded according to consumer specifications,
with many sub-quality units being graded ‘acceptable’ in
order to keep the mass production lines going and the
prices low This has ramifications when the imaging sensor
is graded for defects, or when the IR cutoff glass is
selected during manufacturing. Defects on the glass,
like pits & scratches, or defects in the sensor like
dead pixels or shading artifacts, may not have many consequences
when shooting a birthday party, but when placed on a
collimated light source like the microscope they can
become very noticeable distractions or areas of lost
data. Also consider that most consumer cameras do not
have removable lenses, meaning the thousands of dollars
of investment in good microscope optics will be compromised
by consumer grade optics on the camera’s
primary lens.
Note
also that the quality control procedures on other “inexpensive” digital
microscope cameras may also suffer from lack of stringency
if the camera is not originally intended for a scientific
or specifically microscopic application. “Machine vision” cameras,
or “Industrial grade” cameras, are not intended
for microscopy when manufactured, though some companies will
sell them into this market despite the lower grade of sensors
and artifacts that they can cause.
Color
Balance
When
color balancing a consumer camera, many times the controls
are quite broadly defined. For example, a choice may be
given for switching between a Daylight, Tungsten light,
or Fluorescent light source. By selecting one of these
options, the camera will make internal adjustments to balance
the color of the scene so that it is pleasing to the eye
(that is, will yield appropriate skin tones in your family
photos). In contrast, the PAXcam has a white balance routine
that will take the light that is seen and adjust it specifically
to a balanced white. Whether your microscope is yielding
a color temperature that is towards the blue at higher
voltages or towards the pink at lower voltages, the camera
can quickly make the necessary adjustments to yield images
with an appropriately balanced white background and accurate
color rendition for the scene. Unlike some cameras, this
white balance function can be done even while the sample
is being viewed, by utilizing the special tools provided—no
need to completely fill the field of view with the background
illumination while white balancing.
High Res Flexibility
While
much of the application for Pathology images do not require
super high resolution (see Resolution
discussion section),
the PAXcam ARC does allow for high resolution, large
image sizes to be obtained. One reason for going to high
resolution would be to enable the magnification of detail
in an image that is at the highest magnification possible
on your optical system. With the PAXcam and the PAXcam
ARC, a region of interest can be drawn on the live preview,
allowing the highest resolution capture mode to be applied
to a small area of the field of view. This kind of flexibility
is not available on a consumer camera, meaning that the
highest resolution shots would be taken full field, yielding
huge file sizes with storage & communication
challenges.
Workflow
and Support Issues
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