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Why
does the image look obscure? |
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a. Improper adjustment of back focal length
b. Incompatible lenses specification with sensor type c. Stained
lenses. |
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Why
are not the lenses fixed properly? |
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The screws or other interfaces between
holders and barrels are not coincident. The solutions are that
we provide the barrels and holders or design the barrel complying
with the holder. |
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How
to protect the lenses? |
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Lenses are fragile components. Please
handle with care and protect free of dust. We suggest using
of dust proof covers to prevent the damage or contamination.
For the plastic material, the physical limitations are listed
as follows: |
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Max.
Operating Temperature (C) |
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Abrasion
Resistance
(0-10)
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Sensitivity
to humidity absorption (%) 23C 1week |
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Anti-static
electricity (dust) |
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Impact
strength 1/4” notched |
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How
to calculate angle of view(field of view) ? |
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Answer: See the figure shown below, where
w is angel of view, f indicates focal length and y stands for
image size. In trigonometric function, tan(w/2)=(y’/2)/f,
therefore, w=2tan-1(y’/2f).
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Aberration-see
terminology for explanations. |
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Aberrations are summarized as below, and
you can find the terminology for details.
a. Spherical aberration.
b. Coma aberration (comatic aberration)
c. Chromatic aberration.
d. Astigmatism.
e. Field curvature.
f. Distortion.
g. Flare/ Ghost image.
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Definition
of pixel number? |
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Answer: CIF-100,000 pixels, 640*480 VGA300,000
pixels, 800*600 SVGA480,000, 1024*768 XGA 780,000pixels, 1280*1024
SXGA 1,300,000 pixels, 1600*1200 UXGA 1,920,000 pixels. |
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Definition
of image sensor size? |
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The size of an image sensor is called
its format. The name of a format does not correspond to any
dimension. Historically, a one-half inch format is the size
of the sensing area of a Vidicon tube, which is one-half inch
in diameter. It is important to choose a lens that covers the
camera format. For a given field of view (FOV), the camera format
determines the required magnification. A larger sensor requires
a larger magnification for a given FOV.
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Design
trade off between performance and cost. |
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As we described previously, aberrations
always exist in optical system. We can decrease the aberration
only by using more lenses in product design. Besides, wider
field of view, higher resolution, larger illumination or magnification
surely lead cost higher. |
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