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http://machinevision.navitar.com
• email: [email protected]
Double-Sided Telecentric Lenses
Object and Image Side Telecentricity
Navitar’s Double-Sided Telecentric series of lenses
are telecentric in both the object and image space,
not just the object space as in the design of a normal
telecentric lens. This design allows for telecentricity of
less than 0.1% within the depth of fi eld.
CCD and CMOS sensors continue to be developed
with smaller and smaller pixels while increased elec-
tronic circuitry within the pixel further reduces the
“fi ll factor.” To help focus light onto individual pixels,
camera makers are using micro lens arrays in their de-
signs. While these individual lenses, over each pixel,
serve to collect light, they also pose a challenge to the
optics designer. These micro lenses are most eff ective
when the incoming rays are fi ve degrees or less, of
normal. The telecentric cone of light is a major benefi t
in these situations.
Low Distortion, High Accuracy
Double-Sided Telecentric lenses are less prone to
optical aberrations and geometrical distortions. Image
sizes will not vary across the fi eld due to positioning
of the sensor. Gauging applications will benefi t from
a double-sided telecentric lens compared to a simple
object side only telecentric system. Our lenses are
designed to work with CCD and CMOS sensors up to
28.7mm diagonal. We off er lenses with magnifi cation
from 0.03X to 2.0X as well as large format lenses with
magnifi cation from 0.239X to 0.478X.
Mounting Options
The back focal length is adjusted on the basis of
C-mount or F-mount standard. A spacer kit with
instructions to fi ne tune the back focus for a specifi c
need is included with each lens. Please call for
mounting options.
Sample Product Specifi cation Sheet
Telecentric both in the object and in the
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image space.
Less than 0.1% image distortion within
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the fi eld depth at the fi eld corners.
No image vignetting.
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No parallax error.
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No change of magnifi cation within the
•
depth of fi eld.
MTF greater than 40% at 130 lines/mm.
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Uniform illumination.
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C or F mounts available.
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Specially designed illumination accessories.
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Advantages of Double-Sided Telecentric Lenses
