Telecentric Lenses
Telecentric Lenses
• Zoom telecentric system.
• Single-Sided telecentric lenses.
• Single-Sided telecentric accessories.
• Video telecentric lenses.
• Double-Sided telecentric lenses.
• Double-Sided telecentric illumination accessories.
http://machinevision.navitar.com • email: info@navitar.com
Telecentric Lenses
Telecentric Lenses
Navitar Telecentric Lenses
Navitar o ers a family of high-performance telecentric lenses for use in
machine vision, metrology and precision gauging applications. All provide low
optical distortion and a high degree of telecentricity for maximum, accurate image reproduction, particularly when viewing three-dimensional objects.
Bene ts of Telecentric Lenses
One of the most important bene ts of a telecentric lens is that image magni cation does not change as object distance varies. A telecentric lens views and
displays the entire object from the same prospective angle, therefore, three-dimensional features will not exhibit the perspective distortion and image position
errors present when using a standard lens. Objects inside deep holes are visible
throughout the eld, undistorted, therefore, telecentric lenses are extremely
useful for inspecting three-dimensional objects or scenes where image size and
shape accuracy are critical.
Choose the Best Lens Option for Your Needs
Our machine vision telecentric lenses include the 12X
Telecentric Zoom system, the TC-5028 and TEC-M55
telecentric video lens. Our single-sided lenses, the Invarigon-R™, Macro Invaritar™, ELWD Macro Invaritar™
and Invaritar Large Field telecentric lenses are available with several di erent accessories that enhance
the performance of the lenses. They include teleconverters, right angle attachments, ber bundle collimators and lens mounting brackets. Our Double-Sided
series of lenses are telecentric in both the object and
image space and have optional illumination accessories to provide a bright, even illumination that will
compliment the performance of the lenses.
90
Zoom Telecentric System
-0.04
-0.03
-0.02
-0.01
0
0.01
0.02
0.03
0.04
0.00 0.50 1.00 1.50 2.00
1/4" format
1/3" format
1/2" format
The World’s First Parfocal Telecentric Zoom Lens
The 12X Telecentric Zoom system allows users to reach a true telecentric
condition to within less than 0.3° while maintaining constant perspective
and magni cation. This means that even if the object is slightly out of
focus, the size of the image will not change. The 12X Telecentric Zoom
provides eld coverage from 50 mm down to 4 mm and the coaxial illumination allows clear viewing, even when working with mirror-like surfaces.
Also available without coaxial illumination.
Wide Magni cation Range and Ultra Long Working Distance
In the past, a telecentric lens was de ned as having xed magni cation. Not anymore! The Navitar 12X Telecentric Zoom lens allows you
to zoom in and focus over a wide variety of magni cations with a higher
level of accuracy than you ever thought possible. The 12X Telecentric
Zoom provides adjustable focal lengths over a 0.16X to 1.94X magni cation range. You no longer have to be limited by telecentric lenses that
only o er xed magni cation. Now you have eld coverage from 50 mm
down to 4 mm at a 188 mm working distance.
No Need to Change Lenses
The easily adjustable eld of view and magni cation allow
our Navitar 12X Telecentric lens to adjust to meet your
12X Telecentric Accuracy
exact requirements. It’s no longer necessary to change
lenses, mix and match base lenses with attachment lenses
or recalibrate. One lens, the 12X Telecentric, really does
it all! Straight, as well as right angle, versions allow OEM
designers to best t the systems to their mechanical design.
Telecentric Lenses
Telecentric Error Over Depth
12X Telecentric Lens Speci cations
Telecentric Error
(degrees)
Mag. 1/4” 1/3” 1/2” 1/4” 1/3” 1/2” 1/4” 1/3” 1/2”
0.16 0.05 0.06 -0.03 0.005 0.032 38.8 0.018 0.020 -0.009 25.0 37.3 49.7 15 33
0.23 -0.10 -0.09 -0.18 0.007 0.031 19.4 -0.017 -0.016 -0.030 17.4 26.1 34.8 22 23
0.33 -0.19 -0.18 -0.27 0.010 0.030 10.3 -0.016 -0.016 -0.024 12.1 18.2 24.3 30 17
0.47 -0.23 -0.23 -0.31 0.013 0.028 6.0 -0.012 -0.012 -0.016 8.5 12.8 17.0 39 13
0.67 -0.25 -0.25 -0.34 0.016 0.024 3.8 -0.008 -0.008 -0.011 5.9 8.9 11.9 49 10
0.96 -0.27 -0.27 -0.36 0.020 0.021 2.6 -0.006 -0.006 -0.008 4.2 6.3 8.4 59 8
1.36 -0.29 -0.29 -0.38 0.024 0.017 1.8 -0.004 -0.005 -0.006 2.9 4.4 5.9 71 7
1.94 -0.25 -0.24 -0.29 -0.028 0.015 1.3 -0.003 -0.003 -0.003 2.1 3.1 4.1 84 6
Distortion < 0.1% for all magni cations. Working Distance = 188 mm for all magni cations.
Object
N.A.
Image
N.A.
Object
Depth of
Focus
(mm)
Wide Range of Applications
Speci cally designed for precise dimensional measurement
of objects or pattern recognition, the 12X Telecentric Zoom
has many applications. It’s ideal for measuring three-dimensional objects with deep features, such as well plates,
electrical connector pins, and other precision parts. It’s
also the perfect lens for viewing inconsistently placed parts
on a conveyer belt.
Telecentric Error
(mm)
Object Size
Approx.
MTF
(Ip/mm)
Resolvable
Features
(microns)
91Ph o n e : 8 0 0 - 8 2 8 - 6 7 7 8 o r 5 8 5 - 3 5 9 - 4 0 0 0 • Fax 585-359-4999
Telecentric Lenses
http://machinevision.navitar.com • email: info@navitar.com
working
distance
diameter
f53.6 (2.11)
4.0 (.16)
f29.5 (1.16)
1-32 UNF (C-mount)
clamp in this area
INVARIGON P/N LGU
length
dimensions in mm (in.)
Single-Sided Telecentric
Invarigon-R™
The Invarigon-R™ family of gauging lenses provides telecentric imaging with a wide selection of magni cations.
gauging lenses are the most cost-e ective choice for critical inspection and metrology imaging applications.
Features
Telecentric performance (<0.2° chief ray angle over
the entire object eld) allows precise gauging of
3-dimensional objects.
•
Large selection of magni cations covers most applications.
• Lockable aperture adjusts to select the required
depth of eld.
• Fine focus adjustment provides sharper images.
Rugged single-piece design stands up to harsh •
industrial environments.
High-performance multi-layer coatings provide the• highest image clarity, especially for back-lit applications.
Standard C-mount camera interface. •
Invarigon-R™
Invarigon-R™ Lens Speci cations
Part Number
59 LGU 013 0.13X 217 8.5 80 3.2 190 7.4 1.02 x 1.36 1.36 x 1.81 N/A 1.4 4 1.66
59 LGU 016 0.16X 176 6.9 70 2.8 150 6.0 0.82 x 1.09 1.09 x 1.45 N/A 1.4 5.6 1.06
59 LGU 018 0.18X 154 6.1 61 2.4 130 5.2 0.71 x 0.95 0.95 x 1.27 N/A 1.4 5.6 0.81
59 LGU 022 0.22X 170 6.7 70 2.8 150 6.0 0.59 x 0.78 0.78 x 1.04 1.07 x 1.43 1.6 8 0.54
59 LGU 025 0.25X 148 5.8 61 2.4 130 5.2 0.51 x 0.68 0.68 x 0.91 0.94 x 1.25 1.6 8 0.42
59 LGU 029 0.29X 126 4.9 54 2.1 110 4.4 0.44 x 0.59 0.58 x 0.78 0.80 x 1.07 1.6 8 0.31
59 LGU 031 0.31X 171 6.7 70 2.8 150 6.0 0.41 x 0.54 0.54 x 0.72 0.74 x 0.99 2.3 8 0.27
59 LGU 036 0.36X 149 5.9 61 2.4 130 5.2 0.36 x 0.47 0.48 x 0.63 0.66 x 0.87 2.3 8 0.20
59 LGU 042 0.42X 126 5.0 54 2.1 110 4.4 0.31 x 0.41 0.41 x 0.54 0.56 x 0.74 2.3 8 0.15
59 LGU 050 0.50X 105 4.1 54 2.1 90 3.6 0.26 x 0.34 0.34 x 0.45 0.47 x 0.62 2.3 11 0.10
1
The maximum object dimensions shown in the table are 90% of the theoretical maximum dimensions, providing a safety factor for magni cation and alignment errors.
2
Image-side working f/# with lens aperture fully open. For combinations with teleconverters, the minimum image-side f-number is increased by the teleconverter
magni cation.
3
Lenses operated at smaller f/# may show reduced resolution, especially near the edge of the eld of view.
4
Depth of eld is calculated at f/11 for lenses with minimum operating f/# < f/16 (f/22 for all others) and for 30-µm allowable blur at the image (camera) plane.
Note: Distortion is less than 1.2% for all lenses. Contact Navitar for speci c
distortion characteristics for a particular lens.
Accessory Note:
Mag.
(nominal)
Teleconverter accessories
Invarigon-R™ lenses (59 LGU 031, 59 LGU 036,
59 LGU 042, 59 LGU 050) to increase magni cation by
Length Diameter
mm. in. mm. in. mm. in. 1/3” CCD 1/2” CCD 2/3”CCD
can be used with select
a factor of 1.5x or 2.0x depending on the lens combination. Teleconverters cannot be used with certain types of
3-CCD color cameras.
Working
Distance Maximum Object Dimensions (in)
1
Min f#
2
Min.
Operating
3
f#
Depth of
Field
4
(in.)
92
Single-Sided Telecentric
diameter
6.25 8 1116 22
working
distance
1-32 UNF (C mount)
3.5 (.14)
length
dimensions in mm (in.)
Macro Invaritar™
The Macro Invaritar™ telecentric gauging lenses provide exceptional telecentric imaging performance and are the best
choice for machine vision applications involving signi cant space limitations.
Features
Telecentric performance (<0.25° chief ray •
angle over the entire object eld) allows precise gauging of 3-dimensional objects.
Low distortion (<0.1% over the entire object •
eld) provides highly accurate images.
Small footprint to t into restricted spaces. •
Rugged single-piece design stands up to harsh •
industrial environments.
Lockable aperture adjusts to select the required •
depth of eld.
Standard C-mount camera interface. •
Telecentric Lenses
Macro Invaritar™ Lens Speci cations
Part
Number
59 LGM 205 0.05X 104 4.1 42 1.7 48 1.9 6.5 x 8.6 8.6 x 11.5 11.9 x 15.8 12 - 32 3.84
59 LGM 601 1x 110 4.3 32 1.2 46 1.8 3.2 x 4.3 4.3 x 5.8 5.9 x 7.9 6.25 - 32 1.92
59 LGM 602 2x 107 4.2 32 1.2 25 1.0 1.6 x 2.2 2.2 x 2.9 3.0 x 4.0 3.12 - 16 0.48
59 LGM 605 5x 175 6.9 41 1.6 36 1.4 0.6 x 0.9 0.9 x 1.2 1.2 x 1.6 2.5 - 8 0.10
1
Tolerance on speci ed magni cation is ±3%.
2
The maximum object dimensions shown in the table are 90% of the theoretical maximum dimensions, providing a safety factor
for magni cation and alignment errors.
3
ƒ/# speci ed in object space.
4
Depth of eld is calculated at largest available for each lens ƒ/# and for a 30-µm allowable blur at the image (camera).
1
Mag.
(nominal)
Length Diameter Working Dist. Maximum Object Dimensions (mm.)
mm. inches mm. inches mm. inches 1/3” CCD 1/2” CCD 2/3”CCD
2
f# Range
3
Depth of
Field
(mm)
4
93Ph o n e : 8 0 0 - 8 2 8 - 6 7 7 8 o r 5 8 5 - 3 5 9 - 4 0 0 0 • Fax 585-359-4999
Telecentric Lenses
http://machinevision.navitar.com • email: info@navitar.com
M52!0.75 thread (internal)
55 (2.2)
16 11 8
£/5.6
locking aperture ring
(3!M3 nylon tip set screw)
working distance
length
77 (3.0)
3.2 (.12)
f 40 (1.6)
1-32 UNF (C mount)
dimensions in mm (in.)
Single-Sided Telecentric
ELWD Macro Invaritar™
ELWD (Extra-Long Working Distance) Macro Invaritar™ telecentric gauging lenses provide exceptional imaging
performance and are the best choice for machine vision applications where an extra-long working distance is
required.
Features
Telecentric performance (<0.1° chief ray •
angle over the entire object eld) allows precise gauging of 3-dimensional objects.
Low distortion (<0.5% over the entire object •
eld) provides highly accurate images.
Long working distance permits convenient •
mounting.
Rugged single-piece design stands up to harsh •
industrial environments.
Lockable aperture adjusts to select the required •
depth of eld.
Standard C-mount camera interface. •
ELWD Macro Invaritar Speci cations
Part Number
59 LGN 702 2x 186 7.3 116 4.5 1.6 x 2.2 2.2 x 2.9 3.0 x 4.0 5.6 - 16 0.48
59 LGN 703 3x 256 10.1 105 4.1 1.1 x 1.4 1.4 x 1.9 2.0 x 2.6 5.6 - 16 0.32
59 LGN 704 4x 303 11.9 101 4.0 0.8 x 1.1 1.1 x 1.4 1.5 x 2.0 5.6 - 16 0.24
59 LGN 705 5x 362 14.2 98 3.9 0.6 x 0.9 0.9 x 1.2 1.2 x 1.6 5.6 - 16 0.19
1
The maximum object dimensions shown in the table are 90% of the theoretical maximum dimensions, providing a safety factor for magni cation and
alignment errors.
2
ƒ/# speci ed in object space.
3
Depth of eld is calculated at largest available for each lens ƒ/# and for a 30-µm allowable blur at the image (camera).
Mag.
(nominal)
Length WD. Maximum Object Dimensions (mm.)
mm. inches mm. inches 1/3” CCD 1/2” CCD 2/3”CCD
1
f#
Range
2
Depth of
Field
3
(mm.)
94
Single-Sided Telecentric
diameter
length
attachment lens
F-mount base lens
attachment lens
C-mount base lens
optional
teleconverte
r
Invaritar™ Large Field
Invaritar™ modular, large- eld telecentric gauging lenses provide a wide range of solutions for a variety of machine
vision applications. A telecentric lens system is created by combining a base lens with an appropriate attachment
lens to achieve the required magni cation and eld of view.
Features
Telecentric performance of less than 0.5-degree •
chief ray angle over the entire object eld allows
precise gauging of 3-dimensional objects.
Large selection of base and attachment lenses •
covers most applications.
Low distortion provides for highly accurate •
images.
C-mount Base Lenses
Part Number
59 LGC 516 55 2.2 52 2.1 0.15 0.32
59 LGG 925 53 2.1 30 1.2 0.08 0.17
59 LGG 935 46 1.8 30 1.2 0.08 0.17
59 LGG 950 55 2.2 30 1.2 0.08 0.17
Length Diameter Weight
mm. inches mm. inches kg. lb.
Attachment Lenses
Part Number
59 LGH 416 121 4.8 84 3.3 0.64 1.40
59 LGJ 423 206 8.1 121 4.8 1.76 3.87
59 LGL 428 269 10.6 150 5.9 4.00 8.80
59 LGH 431 275 10.8 84 3.3 0.81 1.78
Length Diameter Weight
mm. inches mm. inches kg. lb.
Lockable aperture adjusts to select the re• quired
depth of eld.
C-mount lenses include ne focus adjust• ment,
providing sharper images.
High-performance multi-layer coatings pro• vide
the highest image clarity, especially for backlit
applications.
Both C-mount and F-mount base lenses are• available.
Telecentric Lenses
F-mount Base Lenses
Part Number
59 LGB 435 74 2.9 76 3.0 0.04 0.9
59 LGB 450 57 2.2 76 3.0 0.04 0.8
59 LGB 485 68 2.7 82 3.2 0.06 1.3
59 LGB 499 117 4.6 85 3.3 0.08 1.8
Length Diameter Weight
mm. inches mm. inches kg. lb.
95Ph o n e : 8 0 0 - 8 2 8 - 6 7 7 8 o r 5 8 5 - 3 5 9 - 4 0 0 0 • Fax 585-359-4999
http://machinevision.navitar.com • email: info@navitar.com
Single-Sided Telecentric
attachment lens
C-mount base lens
optional
teleconverte
r
Invaritar™ Large Field (Continued)
C-mount Invaritar™ Large-Field Telecentric Lens Specications
(for camera formats less than or equal to 2/3”)
Telecentric Lenses
Working
Mag.
(nominal)
0.06x 241 9.5 2.23 x 2.98 N/A N/A 2.0 7.22
0.07x 203 8.0 1.83 x 2.44 N/A N/A 2.8 5.0
0.09x 241 9.5 1.43 X 1.90 1.90 X 2.54 2.62 X 3.49 2.0 3.21
0.10x 140 5.5 1.28 X 1.70 N/A N/A 5.6 2.60
0.11x 203 8.0 1.17 X 1.56 1.56 X 2.09 2.15 X 2.87 2.8 2.15
0.11x 267 10.5 1.13 x 1.51 1.51 x 2.01 N/A 2.8 2.15
0.13x 241 9.5 1.02 X 1.36 1.36 X 1.81 1.87 X 2.49 2.0 1.54
0.15x 203 8.0 0.84 X 1.12 1.12 X 1.49 1.54 X 2.05 5.6 1.15
0.16x 140 5.5 0.82 X 1.09 1.09 X 1.45 1.50 X 2.00 11.0 1.02
0.16x 267 10.5 0.79 X 1.06 1.06 X 1.41 1.45 X 1.94 2.8 1.02
0.18x 241 9.5 0.71 X 0.95 0.95 X 1.27 1.31 X 1.74 5.6 0.80
0.22x 140 5.5 0.58 X 0.78 0.78 X 1.04 1.07 X 1.42 11.0 0.54
0.22x 203 8.0 0.59 X 0.78 0.78 X 1.05 1.08 X 1.44 5.6 0.54
0.24x 267 10.5 0.53 X 0.70 0.07 X 0.94 0.97 X 1.29 4.0 0.45
0.27x 241 9.5 0.48 X 0.64 0.63 X 0.85 0.87 X 1.16 11.0 0.36
0.31x 140 5.5 0.41 X 0.54 0.54 X 0.72 0.75 X 1.00 11.0 0.27
0.32x 267 10.5 0.39 X 0.53 0.53 X 0.70 0.72 X 0.97 5.6 0.25
0.33x 203 8.0 0.39 X 0.52 0.52 X 0.70 0.72 X 0.96 5.6 0.24
036x 241 9.5 0.36 X 0.48 0.48 X 0.64 0.66 X 0.87 16.0 0.29
0.43x 203 8.0 0.29 X 0.39 0.39 X 0.52 0.54 X 0.72 16.0 0.20
0.47x 140 5.5 0.27 X 0.36 0.36 X 0.48 0.50 X 0.66 11.0 0.12
0.63x 140 5.5 0.20 X 0.27 0.27 X 0.36 0.37 X 0.50 16.0 0.10
Distance Maximum Object Dimensions (mm.)
mm. inches 1/3” CCD 1/2” CCD 2/3”CCD
1
Minimum
Operating
F# Range
2
Depth
of
Field
3
(in)
for Required Optical Components
Base Lens Attach.
59 LGC 916 59 LGL 428 none
59 LGC 916 59 LGJ 423 none
59 LGG 925 59 LGL 428 none
59 LGC 916 59 LGH 416 none
59 LGG 925 59 LGJ 423 none
59 LGG 935 59 LGH 431 none
59 LGG 935 59 LGL 428 none
59 LGG 935 59 LGJ 423 none
59 LGG 925 59 LGH 416 none
59 LGG 950 59 LGH 431 none
59 LGG 950 59 LGL 428 none
59 LGG 935 59 LGH 416 none
59 LGG 950 59 LGJ 423 none
59 LGG 950 59 LGH 431 59 LGZ 415
59 LGG 950 59 LGL 428 59 LGZ 415
59 LGG 950 59 LGH 416 none
59 LGG 950 59 LGH 431 59 LGZ 420
59 LGG 950 59 LGH 423 59 LGZ 415
59 LGG 950 59 LGL 428 59 LGZ 420
59 LGG 950 59 LGJ 423 59 LGZ 420
59 LGG 950 59 LGH 416 59 LGZ 415
59 LGG 950 59 LGH 416 59 LGZ 420
Part Numbers
Lens
Tele-
converter
4
1. The maximum object dimensions shown in the table are 90% of the theoretical maximum dimensions, providing safety factor of magnication and alignment errors.
2. Lenses operated at smaller f/# may show reduced resolution, especially near the edge of the eld of view.
3. Depth of eld is calculated for a 30-µm allowable blur at the image (camera) plane at f/11 (for lenses with minimum operating f-number<f/16) or f/22 (for all others).
4. Teleconverters 59 LGZ 420 and 59 LGZ 415 cannot be used with certain types of 3-CCD color cameras.
Note: Distortion is less than 2% for all lenses. Contact Navitar for distortion characteristics for a specic lens.
Invaritar™ Large-Field C-mount Lens
96
Single-Sided Telecentric
attachment lens
F-mount base lens
Invaritar™ Large Field (Continued)
F-mount Invaritar™ Large-Field Telecentric Lens Specications
(for camera formats greater than 2/3”)
Maximum
Mag.
(nom.)
0.13x 241 9.5 2.61 x 2.61 16.0 2.24
0.15x 203 8.0 2.14 X 2.14 16.0 1.68
0.18x 241 9.5 1.83 X 1.83 16.0 1.17
0.22x 140 5.5 1.49 X 1.49 16.0 0.78
0.22x 203 8.0 1.50 X 1.50 16.0 0.78
0.27x 267 10.5 1.19 X 1.19 2.8 0.36
0.30x 241 9.5 1.07 X 1.07 16.0 0.42
0.31x 140 5.5 0.04 X 0.04 16.0 0.39
0.32x 267 10.5 0.01 X 0.01 4.0 0.25
0.36x 241 9.5 0.91 X 0.91 16.0 0.29
0.37x 203 8.0 0.88 X 0.88 16.0 0.28 59 LGB 485 59 LGJ 423
0.43x 203 8.0 0.75 X 0.75 16.0 0.20 59 LGB 499 59 LGJ 423
0.53x 140 5.5 0.61 X 0.61 8.0 0.09 59 LGB 485 59 LGH 416
0.63x 140 5.5 0.52 X 0.52 8.0 0.07 59 LGB 499 59 LGH 416
Working Distance
mm. in. 1” CCD Base Lens Attach. Lens
Object Dimen-
sions (in.)1
Minimum
Operating
F# 2
Depth of Field
(in) 3
Part # for Required
Optical Components
59 LGB 435 59 LGL 428
59 LGB 435 59 LGJ 423
59 LGB 450 59 LGL 428
59 LGB 435 59 LGH 416
59 LGB 450 59 LGJ 423
59 LGB 485 59 LGH 431
59 LGB 485 59 LGL 428
59 LGB 450 59 LGH 416
59 LGB 499 59 LGH 431
59 LGB 499 59 LGL 428
Telecentric Lenses
1. The maximum object dimensions shown in the table are 90% of the theoretical maximum dimensions for a 9.2 mm x 9.2 mm (Kodak MegaPlus) format sensor;
providing a safety factor of magnication and alignment errors. For larger arrays, contact Navitar.
2. Lenses operated at smaller f/# may show reduced resolution, especially near the edge of the eld of view.
3. Depth of eld is calculated for a 30-µm allowable blur at the image (camera) plane at f/11 (for lenses with minimum operating f-number <f/16) or f/22 (for all others).
Note: Distortion is less than 2% for all lenses. Contact Navitar for distortion characteristics for a specic lens.
An accessory C-mount adaptor (59 LGT 101) is required for coupling F-mount Invaritar™ base lenses to a C-mount camera.
Invaritar™ Large-Field F-mount Lens
97Ph o n e : 8 0 0 - 8 2 8 - 6 7 7 8 o r 5 8 5 - 3 5 9 - 4 0 0 0 • Fax 585-359-4999
Telecentric Lenses
http://machinevision.navitar.com • email: info@navitar.com
C-mount
(1"-32 TPI)
f58.42 (2.30)
28.65 (1.13)
C ADAPTOR -NIF-
F-mount
length
diameter
internal
F-mount
external
F-mount
teleconverter
length
C-mount
(1"-32 TPI)
f48.0 (1.89)
dimensions in mm (in.)
Single-Sided Telecentric Lens
Accessories
Navitar o ers several di erent accessories to enhance the performance of their Machine Vision telecentric lenses.
These include: teleconverters to increase magni cation, right angle attachments for viewing of objects up to 360
degrees about the optical axis, ber bundle collimators to provide collimated backlighting and anodized mounting
brackets for proper mounting of the Invarigon-R™ and Invaritar™ lenses.
Teleconverters
When a closer view of objects is required, use a 59
LGZ-series teleconverter with your InvaritarTM large eld gauging lens. Mounted between the lens and the
camera, these teleconverters increase magni cation by
up to 2.0×. Their compact size has minimum impact
on overall lens/camera length. Teleconverters increase
lens f-number and contribute to overall image distortion. Teleconverters cannot be used with some 3-CCD
color cameras.
Features:
Rugged, chrome-plated brass construction stands •
up to harsh environments.
Multiple-element, anti-re ection coated lens •
systems provide optimum performance.
HE15-1/2XE teleconverters for C-mount lenses
59 LGZ 814/820 teleconverters for F-mount lenses
Teleconverter Speci cations
Part Number Mag. Mount
HE15-1 1.5X C-mount LFJ, LGC Original x 1.5 Original x 1.5 Original / 1.5 Original / 1.5 4.9/0.2 -
2XE 2.0X C-mount LFJ, LGC Original x 2.0 Original x 2.0 Original / 2.0 Original / 2.0 7.7/0.3 -
59 LGZ 814 1.4X F-mount LAF. LGB Original x 1.4 Original x 1.4 Original / 1.4 Original / 1.4 - -
59 LGZ 820 2.0X F-mount LAF. LGB Original x 2.0 Original x 2.0 Original x 2.0 Original x 2.0 36/1.4 69/2.7
Applicable
Lens
F/# Change
Focal Length
Change
Field of View
Change
Adapter
The 59 LGT 101 adapter is used to convert from the
F-mount (bayonet type) to the C-mount (1-inch, 32
TPI) thread for CCD cameras.
98
Part Number Description
59 LGT 101
F-mount to C-mount Converter
Obj. Dimensions
Change
Length
(mm./in.)
Diameter
(mm./in.)
Right Angle Attachments
INVARITAR 90
object
plane
C
mount
f64 (2.5)
M4 setscrews, 3@120º apart
C
D
A
B
lens
dimensions in mm (in.)
These attachments allow Invaritar™ lenses to view
objects at right angles to the lens axis. The telecentricity, resolution, low distortion, and high contrast of the
lenses are preserved. The attachments can be rotated
360 degrees around the lens optical axis to provide
viewing in any direction.
Applications
These attachments are useful whenever it is dif cult to point a lens directly at the object. They
are especially helpful when adapting new optics
to existing equipment, where space is limited.
Restrictions
Right angle attachments are only usable only •
with speci ed lenses.
Combined working distance is less than with •
lens alone.
Accessories
Right Angle Attachments
Part Number Description
59 LSF 101
Right-Angle Attachment for Macro Invaritar Lens
Compatiable with Part Number 59 LGM 601
Continued
Telecentric Lenses
Macro Invaritar & Invarigon Lenses with
Right Angle Attachments
59 LSF 401 Right-Angle Attachment for Invarigon-R Lenses
Right Angle Attachment Speci cations
A
(mm./in.)B (mm./in.)C (mm./in.)D (mm./in.)
Right Angle Attachment 59 LSF 101
33.0/1.3 15.2/0.6 144.8/5.7 121.9/4.8 59 LGM 601
Right Angle Attachment 59 LSF 401
76.2/3.0 45.7/1.8 195.6/7.7 162.6/6.4 59 LGU 042
116.8/4.6 86.4/3.4 243.8/9.6 210.8/8.3 59 LGU 050 + 59 LGZ 415
55.9/2.2 25.4/1.0 172.7/6.8 139.7/5.5 59 LGU 050
95.6/3.8 66.0/2.6 223.5/8.8 190.5/7.5 59 LGU 036 + 59 LGZ 415
116.8/4.6 86.4/3.4 246.4/9.7 213.4/8.4 59 LGU 031 + 59 LGZ 420
76.2/3.0 45.7/1.8 200.7/7.9 167.6/6.6 59 LGU 042 + 59 LGZ 415
96.5/3.8 66.0/2.6 226.1/8.9 193.0/7.6 59 LGU 036 + 59 LGZ 420
55.9/2.2 25.4/1.0 177.8/7.0 144.8/5.7 59 LGU 050 + 59 LGZ 415
76.2/3.0 45.7/1.8 203.2/8.0 170.2/6.7 59 LGU 042 + 59 LGZ 420
55.9/2.2 25.4/1.0 180.3/7.1 147.3/5.8 59 LGU 050 + 59 LGZ 420
Additional information and product
speci cations for telecentric lenses
available at machinevision.navitar.com
Use with Invarigon-R
Macro Invaritar Lenses
99Ph o n e : 8 0 0 - 8 2 8 - 6 7 7 8 o r 5 8 5 - 3 5 9 - 4 0 0 0 • Fax 585-359-4999
Telecentric Lenses
http://machinevision.navitar.com • email: info@navitar.com
190 (7.5)
f53 (2.1)
10 (0.4)
fiber optic bundle
Single-Sided Telecentric Lens
Accessories
Fiber Bundle Collimator
This unit provides a large collimated beam for lighting
machine vision applications. It accepts the output
from a standard 59 QLS 700 ber optic bundle. The
uniform, collimated beam is useful for back lighting
objects for gaging and feature inspection. The spectral
content of the light is controlled by ltering at the
ber optic light source.
To make precise machine vision measurements,
correct lighting is essential. Back lighting is useful for measuring the exterior dimension of opaque
objects, or to measure the dimensions of holes
through opaque objects. With di use back lighting,
rays from the edges of the eld can re ect from the
edge of the object and confuse the image. A collimated light source eliminates the confusing rays. This is
especially important when the object being measured
is smooth, shiny or round.
Fiber Bundle Collimator
Part Number Description
59 LGQ 035
Fiber Bundle Collimator
Features
Large clear aperture •
Compatible with 59 QLS 700 •
Low divergence angle •
Speci cations
Length: 190 mm •
Diameter: 53 mm •
Fiber input: 10 mm diameter •
Clear aperture: 35 mm •
Divergence angle: 11 arc min •
59 LGQ 035 Outline Drawing & Dimensions
Dimensions in mm (inches)
100
C
fB
fA
D clamp screw
E
2! F tapped holes
Lens Mounting Brackets
Use these brackets to clamp the Invaritar™ and
Invarigon-R™ lenses to your application. This
accessory clamps directly around the lens barrel
and includes convenient standard-sized tapped
mounting holes. The 59 LGP 717 is similar to the
59 LGP 403 and 59 LGP 414 except that it was
designed for use with the 59 LGN series Extra Long
Working Distance Macro Invaritar™ lenses.
Note: Clamping around the barrel immediately
over the front lens element is not recommended.
If mounting larger sized Invaritar base/attachment
lens combinations, two clamps are recommended.
Features
Accessories Continued
Telecentric Lenses
Clamps directly around lens barrel diam-•
eter for rigid attachment
Rugged anodized-alumium construction•
M6 or 1/4-20 tapped mounting holes•
Lens Mounting Bracket Speci cations
Part Number Description A (mm./in.) B (mm./in.) C (mm./in.) Thread D E (mm./in.) Thread F
59 LGP 403 Standard Mounting Bracket 76.2 / 3.0 53.3 / 2.1 33.0 / 1.3 10-32 20.3 / 0.8 1/4 - 20
59 LGP 414 Mounting Bracket for Macro Invaritar 57.1 / 2.3 33.0 / 1.3 27.9 / 1.1 10-32 12.7 / 0.5 1/4 - 20
59 LGP 717 Mounting Bracket for ELWD Lenses 66.0 / 2.6 40.6 / 1.6 27.9 / 1.1 M6 22.9 / 0.9 M6
Additional information and product speci cations for
telecentric lenses available at machinevision.navitar.com
101Ph o n e : 8 0 0 - 8 2 8 - 6 7 7 8 o r 5 8 5 - 3 5 9 - 4 0 0 0 • Fax 585-359-4999
Telecentric Lenses
http://machinevision.navitar.com • email: info@navitar.com
Video Telecentric Lenses
TC-5028
The Navitar TC-5028 telecentric lens is a 50 mm
F/2.8 telecentric lens which reduces or eliminates
viewing angle error and magni cation error while
providing high resolution and contrast with low
distortion. This compact, lightweight lens can be
used with 1/3”, 1/2” and 2/3” format cameras and is
usable from 0.5X to 1.0X, 1:1.
TC-5028 Video Lens Speci cations
Part Number TC-5028
Focal Length 50 mm
Iris Range/ F-Stop 2.8 - Close
Iris Manual
Control
Object Area
at M.O.D
(HxV)
Focusing Range (meters) 0.5 - in nity
Field Angle
(HxV)
Back Focal Length (mm) 32.5
Filter Diameter Ø37 P=0.75
Mount C-mount
Weight (grams) 318
Exit Pupil Position 48.1(from image plane)
Distortion in TV
Vignetting 97%
Filter Size M37 P0.75
Focus Manual
Zoom N/A
2/3” 8.1 x 6.1
1/2” 5.9 x 4.4
1/3” 3.8 x 3.3
1/4” 2.9 x 2.2
2/3” 10º 03’ x 7º 33’
1/2” 7º 19’ x 5º 29’
1/3” 5º 29’ x 4º 07’
1/4” 3º 39’ x 2º 45’
Less than 0.1%
TC-5028 Outline Drawing
with Dimensions
Speci cations for Telecentric Use
Magni cations
Distortion at 0.5X -0.3%
Distortion at 1.0X Less than - 0.1%
Distance from Front
Lens to Object
0.5 1.0X
0.5X:115mm
1.0X:85mm
102
Video Telecentric Lenses
TEC-M55
Navitar also o ers the TEC-M55 telecentric C-mount
lens for 2/3” format cameras. This 55 mm F/2.8
telecentric lens maintains constant perspective and
magni cation.
Conventional lenses are often unable to accurately
portray objects which are slightly out of focus or at
di erent distances from the lens. Constant perspective
and magni cation are maintained with a telecentric
lens, so the size of the image will not change.
TEC-M55 Video Lens Speci cations
Part Number
Focal Length 55 mm
Iris Range/ F-Stop 2.8 - 32C
Iris Manual
Control
Object Area at
M.O.D (HxV)
Focusing Range (meters) 0.14 - in nity
Field Angle (HxV) 2/3” 9.2º’ x 6.97º
Back Focal Length (mm) 29.8
Filter Diameter Ø43 P=0.75
Mount C-mount
Weight (grams) 320
Exit Pupil Position 30.3 (from image plane)
Focus Manual
Zoom N/A
2/3” 17 x 13
TEC-M55
Telecentric Lenses
TEC-M55 Outline Drawing
with Dimensions
Additional information and product
speci cations for telecentric lenses
available at machinevision.navitar.com
103Ph o n e : 8 0 0 - 8 2 8 - 6 7 7 8 o r 5 8 5 - 3 5 9 - 4 0 0 0 • Fax 585-359-4999
Telecentric Lenses
http://machinevision.navitar.com • email: info@navitar.com
Double-Sided Telecentric Lenses
Advantages of Double-Sided Telecentric Lenses
Telecentric both in the object and in the •
image space.
Less than 0.1% image distortion within •
the eld depth at the eld corners.
No image vignetting. •
No parallax error. •
No change of magni cation within the •
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 eld.
depth of eld.
MTF greater than 40% at 130 lines/mm. •
Uniform illumination. •
C or F mounts available. •
CCD and CMOS sensors continue to be developed
with smaller and smaller pixels while increased electronic circuitry within the pixel further reduces the
“ ll factor.” To help focus light onto individual pixels,
camera makers are using micro lens arrays in their designs. 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 e ective
when the incoming rays are ve degrees or less, of
normal. The telecentric cone of light is a major bene 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 eld due to positioning
of the sensor. Gauging applications will bene 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 o er lenses with magni cation
from 0.03X to 2.0X as well as large format lenses with
magni cation from 0.239X to 0.478X.
Specially designed illumination accessories.•
Sample Product Speci cation Sheet
Mounting Options
The back focal length is adjusted on the basis of
C-mount or F-mount standard. A spacer kit with
instructions to ne tune the back focus for a speci c
need is included with each lens. Please call for
mounting options.
104
Double-Sided Telecentric Lenses for up to 2/3” Format Matrix
1
Part
Number
Mag.
(x)
1/3”
wxh
4.8 x3.6
1-17796 2.00 2.4 x 1.8 3.2 x 2.4 4.4 x 3.3 57.1 11 > 30 0.2 < 0.08 < 0.08 C 101.4 28
1-17797 1.33 3.6 x 2.7 4.8 x 3.6 6.6 x 5.0 61.2 11 > 30 0.5 < 0.08 < 0.08 C 78.5 28
1-17798 1.00 4.8 x 3.6 6.4 x 4.8 8.8 x 6.6 63.3 11 > 25 1 < 0.08 < 0.08 C 65 28
1-17800 0.40 12.0 x 9.0 16.0 x 12.0 diam = 16.5 45.3 8 > 40 4.5 < 0.1 < 0.08 C 92 37.8
1-17801 0.55 8.7 x 6.5 11.0 x 8.7 16.0 x 12.0 45.3 8 > 30 3 < 0.1 < 0.07 C 112 37.8
1-17802 0.27 18.0 x 13.5 24.0 x 18.0 diam = 24.8 69.2 8 > 45 10 < 0.1 < 0.08 C 122.5 44
1-17803 0.37 13.1 x 9.8 17.5 x 13.1 24.0 x 18.0 63.4 8 > 45 7 < 0.1 < 0.1 C 142 44
1-17804 0.13 36.0 x 27.0 diam = 36.0 n.a. 103.5 8 > 50 38 < 0.08 < 0.08 C 133 61
1-17805 0.18 27.0 x 20.3 36.0 x 27.0 diam = 37.1 103.5 8 > 40 22 < 0.08 < 0.1 C 148 61
1-17806 0.24 19.6 x 14.7 26.2 x 19.6 36.0 x 27.0 103.5 8 > 40 12 < 0.08 < 0.1 C 164.9 61
1-17808 0.13 36. 0 x 27.0 48.0 x 36.0 diam = 49.5 134 8 > 40 24 < 0.1 < 0.1 C 180 75
1-17809 0.18 26.2 x 19.6 34.9 x 26.2 48.0 x 36.0 134 8 > 40 14 < 0.1 < 0.1 C 200 75
1-17810 0.11 42.0 x 31.5 56.0 x 42.0 diam = 57.8 159.3 8 > 50 45 < 0.08 < 0.08 C 205 80
1-17811 0.16 30.5 x 22.9 40.7 x 30.5 56.0 x 42.0 159.3 8 > 45 26 < 0.08 < 0.08 C 225 80
1-17812 0.08 64.0 x 48.0 diam = 64.0 n.a. 182.3 8 > 40 130 < 0.08 < 0.07 C 212 100
1-17813 0.10 48.0 x 36.0 64.0 x 48.0 diam = 66.0 182.3 8 > 50 60 < 0.08 < 0.07 C 227 100
1-17814 0.14 34.9 x 26.2 46.5 x 34.9 64.0 x 48.0 182.3 8 > 50 36 < 0.08 < 0.07 C 245.5 100
1-17815 0.12 39.3 x 29.5 52.4 x 39.3 72.0 x 54.0 227.7 8 > 40 48 < 0.08 < 0.07 C 300 120
1-17816 0.08 60.0 x 45.0 80.0 x 60.0 diam = 82.5 227.7 8 > 50 90 < 0.08 < 0.1 C 272 120
1-17817 0.11 43.6 x 32.7 58.2 x 43.6 80.0 x 60.0 227.7 8 > 50 57 < 0.08 < 0.1 C 272 120
1-17818 0.10 46.4 x 34.8 61.8 x 46.4 85.0 x 63.8 280.6 8 > 45 60 < 0.08 < 0.08 C 346 146
1-17819 0.05 96.0 x 72.0 diam = 96.0 n.a. 280.6 8 > 50 240 < 0.08 < 0.1 C 302 146
1-17820 0.07 72.0 x 54.0 96.0 x 72.0 diam = 99.0 279.6 8 > 45 120 < 0.08 < 0.08 C 318 146
1-17821 0.09 52.4 x 39.3 69.8 x 52.4 96.0 x 72.0 279.6 8 > 40 70 < 0.08 < 0.08 C 338 146
1-17822 0.08 60.0 x 45.0 80.0 x 60.0 110.0 x 2.5 336.5 8 > 40 90 < 0.08 < 0.07 C 431 185
1-17823 0.05 90.0 x 67.5 120.0 x 90.0 diam = 123.8 336.5 8 > 45 180 < 0.08 < 0.1
1-17824 0.07 65.5 x 49.1 87.3 x 65.5 120.0 x 90.0 336.5 8 > 35 105 < 0.08 < 0.1 C 422 185
1-17825 0.07 70.9 x 53.2 94.5 x 70.9 130.0 x 97.5 398 8 > 40 150 < 0.08 < 0.1 C 490 200
1-17826 0.04 108.0 x 81.0 144.0 x 108.0 diam = 148.5 398 8 > 35 260 < 0.08 < 0.08 C 483 200
1-17827 0.06 78.5 x 58.9 104.7 x 78.5 144.0 x 108.0 398 8 > 40 160 < 0.08 < 0.08 C 628 200
1-17828 0.05 93.8 x 70.4 125.1 x 93.8 172.0 x 129.0 531 8 > 40 240 < 0.08 < 0.1 C 628 260
1-17829 0.03 144.0 x 108.0 192.0 x 144.0 diam = 198.0 531 8 > 45 360 < 0.08 < 0.08 C 600 260
1-17840 0.05 104.7 x 78.5 139.6 x 104.7 192.0 x 144.0 531 8 > 35 240 < 0.08 < 0.08 C 618 260
1-17841 0.04 109.1 x 81.8 145.5 x 109.1 200.0 x 150.0 500 8 > 40 310 < 0.08 < 0.1 C 785 330
1-17842 0.04 130.9 x 98.2 174.5 x 130.9 240.0 x 180.0 500 8 > 45 380 < 0.08 < 0.08 C 778 330
Object Field
(mm) Optical Specications Dimensions
1/2”
wxh
6.4 x 4.8
2/3”
wxh
8.8 x 6.6
WD
(mm)
F/#
MTF@
3
70lp/
mm%
Field
Depth
4
Telecent.
5
Distortion
(%)
Mount Length
2
6
C 402 185
Diam.
Telecentric Lenses
Large Format Double-Sided Telecentric Lenses Matrix
Part
Number
Mag. (x)
Object Field
4k x 7µm 2k x 10µm 2k x 7µm
1-17843 0.478 60 43 30 230 9 > 30 4 < 0.08 < 0.08 F 460 100
1-17844 0.36 80 57 40 243 9 > 30 7 < 0.01 < 0.10 F 460 120
1-17845 0.239 120 86 60 250 9 > 30 15 < 0.01 < 0.15 F 460 146
1
For the elds with the indication “diam =” the image of a circular object is inscribed inside the short detector side.
2
Working distance: Best focus front lens to object distance. Set this distance within +/- 3% of the nominal value to minimize distortion.
3
Working F/#: The real F/# of a lens when used as a macro lens with a smaller aperture can be supplied upon request.
4
Out of this interval the CTF contrast falls below 50% of the nominal value; the eld depth can be increased by a smaller diaphragm, available on request.
5
Maximum slope of principal rays inside the lens: Turned in millirads. Tells which is the maximum measurement error for any millimeter of object displacement.
6
Measured from the end of the mechanics to the camera ange.
1
(mm) Optical Specications Dimensions
WD
(mm)
2
F/#
3
70lp/mm%
MTF@
Field
Depth
Telecen.5Distortion (%) Mount Length6Diameter
4
105Ph o n e : 8 0 0 - 8 2 8 - 6 7 7 8 o r 5 8 5 - 3 5 9 - 4 0 0 0 • Fax 585-359-4999
Telecentric Lenses
http://machinevision.navitar.com • email: info@navitar.com
Double-Sided Telecentric
Illumination Accessories
Illumination has proven to be one of the most important components when designing a successful imaging system.
Navitar thoroughly understands that the correct lighting will enhance the performance of your vision system. We
oer three LED lighting options specially designed for Double-Sided Telecentric lenses. Our LED Ring Light and
Coaxial Diusive LED lighting accessories were designed for the standard working distances that most of our customers use. Collimated LED accessories are a popular choice for backlighting. All of these components are low prole
and provide bright, even illumination to compliment the performance of our lenses.
LED Ring Light Illumination
Diusive LED ring lights are specically designed to t our DoubleSided Telecentric lenses. The illuminating geometry is tailored for
the specic working distance and aperture.
LED Ring Light Specications
Part
Number
1-17790
1-17791 Red 72 28 36 24V, 300mA
1-17792 White 119 61 36 24V, 600mA
1-17793 Red 119 61 36 24V, 600mA
1-17794 White 160 100 38 24V, 900mA
1-17795 Red 160 100 38 24V, 900mA
Light
White 72 28 36 24V, 300mA
Outer Diameter Lens Opening Height
Dimensions (mm)
Power Supply
LED Ring Light Features:
Special mechanical interfaces. •
Dierent types of diusers. •
Available with red or white LEDs. •
External power supplies.•
Coaxial Diusive LED Illumination
Diusive coaxial lights are designed to be used in
combination with our Double-Sided Telecentric lenses
to image objects with holes or highly reective
surfaces. The target is illuminated in the same
direction of the image capture allowing highly 3Dshaped parts to be imaged and shadows removed.
Coaxial Diusive LED Features:
Built-in electronics for stability control. •
Compact design with thermal management. •
Cost-eective. •
A range of sizes to select from.•
Coaxial Diusive LED Specications
Spectrum Illuminance at Working Distance
Part Number Window (mm)
1-17786 50.0 x 50.0 108.0 x 57.0 x 62.0 Red - 625nm 4700 980 310
1-17787 50.0 x 50.0 108.0 x 57.0 x 62.0 White 5500 - 3300 800 250
1-17788 82.0 x 82.0 155.0 x 104.0 x 93.0 Red - 625nm 4500 910 270
1-17789 82.0 x 82.0 155.0 x 104.0 x 93.0 White 5500 - 2800 750 210
106
(LxH)
Dimensions (mm)
(LxWxH)
Color K Peak wv 50mm 100mm 200mm
LED Ring Light
Coaxial Di usive LED
Collimated LED Illumination
Our collimated light sources are the best choice for back lighting objects imaged through a
telecentric lens for high precision or speed applications, as all of the light exiting the collimator
enters the lens and enters the sensor.
Collimated LED Speci cations
Part Number
1-17765 20 87 38 White
1-17766 30 100 44 White
1-17767 45 139 61 White
1-17846 60 139 75 White
1-17768 70 191 80 White
1-17769 80 219 100 White
1-17770 100 265 116 White
1-17771 120 310 143 White
1-17772 150 396 180 White
1-17773 180 456 200 White
1-17774 250 592 260 White
1-17775 300 747 322 White
1-17776 20 87 38 Red
1-17777 30 100 44 Red
1-17764 45 139 61 Red
1-17847 60 139 75 Red
1-17778 70 191 80 Red
1-17779 80 219 100 Red
1-17780 100 265 116 Red
1-17781 120 310 143 Red
1-17782 150 396 180 Red
1-17783 180 456 200 Red
1-17784 250 592 260 Red
1-17785 300 747 322 Red
Beam
Diameter (mm)
Length (mm) Diameter (mm) LED Color
Collimated LED Features:
Eliminates border e ects that •
can warp the perceived size of
an image.
Effi cient use of light.•
Collimated LED
Telecentric Lenses
Additional information and
product speci cations for
telecentric lenses available at
www.machinevision.navitar.com
107Ph o n e : 8 0 0 - 8 2 8 - 6 7 7 8 o r 5 8 5 - 3 5 9 - 4 0 0 0 • Fax 585-359-4999
http://machinevision.navitar.com • email: info@navitar.com
Telecentricity FAQ’s
What is Telecentricity?
Telecentricity is a distinctive property of certain multi-element lens designs in which the chief rays
(the rays through the center of the entrance or exit pupil), for all points across the object or image, are parallel
to the optical axis.
Telecentric Lenses
Now, what is Telecentricity in English?
Telecentricity is all a matter of perspective distortion, which
is a variation in magnication with distance. A railroad track
that shrinks, or a tall building that gets narrower with height,
are both everyday examples of this. Hold one thumb close to
the eye and the other at arms length. One looks smaller than
the other - your brain knows that’s not so, however, a vision
system doesn’t. The telecentric lens makes all objects, within
the “depth of eld” of the lens, appear to be equidistant from
the lens, thereby eliminating the variation in magnication
with distance (see diagram at right).
Conventional
Lens
Telecentric
Lens
What are the benets of using a Telecentric Lens?
Telecentric lenses provide constant image magnication as
object distance varies - virtually eliminating perspective angle
error. With a telecentric lens, objects inside deep holes are visible throughout the eld, undistorted, therefore, these lenses
are extremely useful for inspecting three-dimensional objects
or scenes where image size and shape accuracy are critical.
Do I need special illumination with a Telecentric lens?
Yes, if you want to derive the full benet of telecentricity. Both incident and transmitted illumination should
meet certain collimation criteria.
How is the degree of telecentricity determined?
The degree of telecentricity is measured by the chief ray angle in the corner of the eld. Telecentric lenses
have chief ray angles of less than 0.5 degrees - some even have less than 0.1 degree. In comparison, a standard
commercial lens may have chief ray angles of 10 degrees or more.
Will using a Telecentric lens improve my depth of eld?
No, telecentricity will keep the magnication constant through the depth of eld. However, the focus will
soften as with any lens. The depth of eld will still be determined by the system’s F/#.
Are Telecentric lenses available with Zoom features?
Yes, Navitar’s 12X Telecentric Zoom system allows users to reach a true telecentric condition to within less
than 0.3 degrees while maintaining constant perspective and magnication. The 12X Telecentric Zoom provides eld coverage from 50 mm down to 4 mm and with coaxial illumination, allows clear viewing, even
when working with mirror-like surfaces.
What is the dierence between a Double-Sided Telecentric lens and a standard Telecentric Lens?
Double-Sided Telecentric lenses provide both image and object side telecentricity. With the single telecentric
lens, the rays at the image plane are still coming in at strong angles. If we “double up” on the lenses, we now
have telecentric performance front and back. The resulting system is less prone to optical aberrations and geometrical distortions. Image size will not vary across the eld due to positioning of the sensor.
Modern sensor pixels are both getting smaller and more cluttered up with electronic circuitry. As light collection is normally a function of active area, manufacturers are adding micro lenses over each pixel to aid in the
collection of light. These micro lenses are most eective when the incoming rays are 5 degrees, or less, o
normal. The telecentric cone of light is a major benet in these situations.
108
Loading...