Infinity-Corrected Tube Lenses

Overview
Specs
Magnification & FOV
Feedback

Objective Lens Selection Guide
Objectives
Super Apochromatic Microscope Objectives Microscopy Objectives, Dry Microscopy Objectives, Oil Immersion Physiology Objectives, Water Dipping or Immersion Long Working Distance Objectives Reflective Microscopy Objectives UV Focusing Objectives 532 nm and 1064 nm Objectives
Scan Lenses and Tube Lenses
Scan Lenses F-Theta Scan Lenses Infinity-Corrected Tube Lenses

Webpage Features
	Zemax black box files (both directions) for all tube lenses except the ITL200 can be accessed by clicking this icon below.

Tube Lens Options
Tube Lens Type	Effective Focal Length	Available Wavelength Ranges
Widefield	200 mm	Visible
		Visible and NIR
		NIR
	180 mm	Visible
	165 mm
	100 mm
Laser Scanning and Widefield	600 mm	Visible
	400 mm
	300 mm
	200 mm	Visible
		Visible and NIR
		NIR

Click for Details
Widefield imaging tube lenses take the collimated light from an infinity-corrected microscope and focus it onto a camera, as shown on the left. Laser scanning tube lenses can be used in telecentric systems to scan a laser spot across a sample.

Features

Tube Lenses for Widefield Imaging
- True Imaging Lenses for Forming a Well-Corrected Infinity Optical System
- Apochromatically Corrected for Diffraction-Limited Performance Across the Field of View
- Better Overall Aberration Correction than Standard Achromats
- 200 mm, 180 mm, 165 mm, or 100 mm Focal Length
- External SM2 or External M38 x 0.5 Threading
Telecentric Tube Lenses for Laser Scanning and Widefield Imaging
- Infinity-Corrected Design
- Forms a Telecentric System When Paired with an SL50 Scan Lens
- 600 mm, 400 mm, 300 mm, or 200 mm Focal Length
- External SM2 Threading
AR Coatings for High Transmission Through Visible and NIR Wavelength Ranges
Compatible with Thorlabs, Nikon, Leica, Olympus, and Zeiss Objectives
Diffraction-Limited Optical Performance

These infinity-corrected tube lenses are designed for use with infinity-corrected objectives from all major manufacturers, including the Dry, Oil Immersion, and Physiology microscope objectives sold by Thorlabs. Designed for high-resolution imaging, biomedical, machine vision, and laser scanning applications, these lenses can be aligned in pairs to create relays, combined with objectives to create different effective magnification ratios at a scientific camera, used as drop-in replacements for tube lenses in existing systems, or integrated into DIY Cerna^® Microscopes and other home-built microscopy setups to generate high-quality images.

Standard Widefield Tube Lenses
Our widefield tube lenses provide diffraction-limited axial color performance in the visible and NIR wavelength ranges. Their effective focal lengths correspond to the design focal lengths of popular objectives (see the Magnification & FOV tab for details). They are AR coated for high transmission at visible and NIR wavelengths; transmission plots are provided in the tables below. The TTL200 series of tube lenses are specifically designed to offer a wider diffraction-limited axial color range than the ITL200 tube lens. Specifications for all lenses can be found on the Specs tab, as well as Zemax black box files for all lenses except the ITL200.

Telecentric Tube Lenses for Laser Scanning and Widefield Imaging
Our laser scanning tube lenses are optimized for laser scanning applications, such as confocal laser scanning, two-photon microscopy, and three-photon microscopy. These lenses create a telecentric system when paired with our SL50-CLS2, SL50-2P2, and SL50-3P scan lenses, for use in point-by-point galvo scanning of the object plane. These lenses can also be used for widefield imaging over their specified wavelength ranges.

Our standard widefield tube lenses can also be used for laser scanning purposes when paired with the CLS-SL Visible Scan Lens, for example. However, using a standard tube lens in a scanning configuration will limit the unvignetted field size, since the tube lens must be placed at the telecentric pupil distance from the objective (e.g., 250 mm for the TTL200 lens), rather than the intended pupil distance of the tube lens.

Microscope and Objective Compatibility
Microscope manufacturers design their systems with one of several standard tube lens focal lengths, including 200 mm (typical for Thorlabs, Nikon, and Leica microscopes), 180 mm (typical for Olympus microscopes), and 165 mm (typical for Zeiss microscopes). Similarly, microscope objectives are designed to provide the magnification engraved on the housing when used with a tube lens of the appropriate standard focal length. We offer infinity-corrected tube lenses in all of these focal lengths so that home-built microscope systems may make use of these industry standards. In addition, some of our 200 mm focal length tube lenses (Item #'s TTL200 and ITL200) have external M38 x 0.5 threads that allow them to serve as drop-in replacements in Thorlabs and Nikon microscopes.

Alternatively, objectives and tube lenses with different design focal lengths may be combined to create different magnification ratios at the camera without compromising the axial color correction. We offer four tube lenses with non-standard focal lengths that can be used to change the magnification of an existing system. To calculate the system magnification for different tube lens and objective combinations, see the Magnification & FOV tab.

Tube Lenses for Widefield Imaging

Item #

TTL200

TTL200-A

TTL200-B

TTL200-S8

ITL200

TTL180-A

TTL165-A

TTL100-A

Effective Focal Length

200 mm ± 1%

200 mm

180 mm ± 1%

165 mm ± 1%

100 mm ± 1%

Working Distance^a,b

148 mm

130 mm

118 mm

60 mm

Pupil Distance^c

70 - 170 mm

50 - 150 mm

0 - 100 mm

Field Size at Image Plane^d

Ø22 mm

Not Available

Ø22 mm

Ø15 mm

Entrance Pupil

Ø20 mm

Not Available

Ø18 mm

Ø16 mm

Ø14 mm

Lens Design

Apochromatic

Design Wavelength Range^b

400 to 750 nm

650 to 1050 nm

400 to 2000 nm

Visible Wavelengths

400 to 750 nm

450 to 750 nm

AR Coating Range

350 - 700 nm

650 - 1050 nm

Broadband Single-Layer
MgF₂ Coating

Visible Wavelengths

350 - 700 nm

Axial Color

Diffraction Limited

Not Available

Diffraction Limited

Resolution

Diffraction Limited^e

Not Available

Diffraction Limited^e

Surface Quality

60-40 Scratch-Dig

Not Available

60-40 Scratch-Dig

External Threading

M38 x 0.5
Bottom Only

SM2 Top and Bottom

M38 x 0.5
Bottom Only

SM2
Top and Bottom

Housing Length

28.0 mm

33.5 mm

30.9 mm

31.1 mm

Performance Data (Click for Graph)

Transmission

Axial Color

400 - 800 nm

650 - 1100 nm

1000 - 2000 nm

Not Available

RMS Wavefront Error

Not Available

MTF

Not Available

Distortion

Not Available

Data

Excel Spreadsheet

Zemax Black Box Files

Forward
Backward

Not Available

Forward
Backward

Measured from the top edge of the housing to the image plane (see the diagram below).
These lenses are designed to provide diffraction-limited performance from 400 nm to 2000 nm; however, the working distance is valid only over the specified design wavelength range. The lens will need to be refocused when used at other wavelengths. Once refocused for a new center wavelength, the performance will be diffraction limited for some finite bandwidth around that wavelength. Nominal bandwidth, working distance, and performance can be estimated using the Zemax black box files. The axial color plots and performance data can be used for guidance when adjusting the working distance.
This is the optimal distance between the tube lens and the entrance pupil of the objective (see the diagram below).
TTL series lenses will provide an unvignetted field up to this diameter so long as the lens is focused at the wavelength of interest, which may be anywhere from the lower end of the design wavelength range up to 2000 nm. For reference, a Ø22 mm field size is large enough to fill a 4/3" format camera sensor.
Appropriate for use with camera pixel sizes down to 2 µm.

Click To Enlarge
This schematic shows the working distance and pupil distance for the TTL series and ITL200 tube lenses. The working distance corresponds to the distance from the top surface of the housing to the image plane. The pupil distance, defined as the distance between the bottom edge of the tube lens housing and the entrance pupil of the objective, can be set anywhere within the range specified in the table above, since the rays from the objective are in parallel bundles. If the tube lens is too close, the image may suffer from aberrations; if it is too far, vignetting will occur.

Lenses with external SM2 threads are engraved with an arrow next to an infinity symbol (∞) to indicate which side of the lens should face the objective (infinity space), as shown in the diagram above. Item #'s TTL200 and ITL200 should be inserted with the M38 x 0.5 threading facing the objective.

Tube Lenses for Laser Scanning and Widefield Imaging

Item #	TL600-A	TL400-A	TL300-A	TTL200MP	TL200-CLS2	TL200-2P2	TL200-3P
Design Wavelength Range	400 - 700 nm			400 - 2000 nm	450 - 1100 nm	680 - 1600 nm	900 - 1900 nm
AR Coating Range	400 - 700 nm			400 - 1300 nm	450 - 1100 nm	680 - 1600 nm	900 - 1900 nm
Effective Focal Length	600 mm	400 mm	300 mm	200 mm
Working Distance^a	91 mm			148 mm	180.9 mm
Pupil Distance^b	123 mm (Telecentric)			228 mm (Telecentric)	189.1 mm (Telecentric)
Track Length	420 mm (Nominal)				409 mm (Nominal)
Exit Pupil Diameter	20 mm			25 mm (Maximum)^c	20 mm (Maximum)^c
f/#	30	20	15	10
Field Size (Diffraction Limited)	Ø22 mm			Ø22 mm	16.3 mm x 16.3 mm (FN23) for 656.3 - 1100 nm; 14.1 mm x 14.1 mm (FN20) at 587.6 nm; 7.8 mm x 7.8 mm (FN11) at 486.1 nm	15.5 mm x 15.5 mm (FN22) for 680 - 1600 nm	15.5 mm x 15.5 mm (FN22) for 900 - 1600 nm; 12.4 mm x 12.4 mm (FN 17.6) at 1900 nm
Clear Aperture	Ø30.7 mm			Ø36.8 mm	Ø47.0 mm
Lens Design	Apochromatic
Axial Color	Diffraction Limited
F-Theta Distortion	<0.5%	<0.2%			<0.3%
Threading	External SM2 Threads (Top and Bottom)				Internal SM2 Threads on Top External SM2 Threads on Bottom
Housing Length	205.7 mm			44.1 mm	41.6 mm
Performance Data (Click for Graph)
Transmission
Axial Color
RMS Wavefront Error
MTF
Data	Excel Spreadsheet	Excel Spreadsheet	Excel Spreadsheet	Excel Spreadsheet	Excel Spreadsheet	Excel Spreadsheet	Excel Spreadsheet
Zemax Black Box Files	Forward Backward	Forward Backward	Forward Backward	Forward Backward	Forward Backward	Forward Backward	Forward Backward

Measured from the housing edge to the intermediate image plane (see the diagram below).
This is the optimal distance between the lens and the objective (see the diagram below).
Lens performance is diffraction-limited for exit pupil diameters up to 20 mm.

Click To Enlarge
This schematic shows the TTL200MP Tube Lens in a laser scanning configuration with the working distance and pupil distance called out. The working distance corresponds to the distance from the edge of the housing below the engraving to the intermediate image plane. The pupil distance is defined as the distance between the edge of the tube lens housing above the engraving and the entrance pupil of the objective.

These lenses are engraved with an arrow next to an infinity symbol (∞) to indicate which side of the lens should face the objective (infinity space), as shown in the diagram above.

When viewing an image with a camera, the system magnification is the product of the objective and camera tube magnifications. When viewing an image with trinoculars, the system magnification is the product of the objective and eyepiece magnifications.

Manufacturer	Tube Lens Focal Length
Leica	f = 200 mm
Mitutoyo	f = 200 mm
Nikon	f = 200 mm
Olympus	f = 180 mm
Thorlabs	f = 200 mm
Zeiss	f = 165 mm

The rows highlighted in green denote manufacturers that do not use f = 200 mm tube lenses.

Magnification and Sample Area Calculations

Magnification

The magnification of a system is the multiplicative product of the magnification of each optical element in the system. Optical elements that produce magnification include objectives, camera tubes, and trinocular eyepieces, as shown in the drawing to the right. It is important to note that the magnification quoted in these products' specifications is usually only valid when all optical elements are made by the same manufacturer. If this is not the case, then the magnification of the system can still be calculated, but an effective objective magnification should be calculated first, as described below.

To adapt the examples shown here to your own microscope, please use our Magnification and FOV Calculator, which is available for download by clicking on the red button above. Note the calculator is an Excel spreadsheet that uses macros. In order to use the calculator, macros must be enabled. To enable macros, click the "Enable Content" button in the yellow message bar upon opening the file.

Example 1: Camera Magnification
When imaging a sample with a camera, the image is magnified by the objective and the camera tube. If using a 20X Nikon objective and a 0.75X Nikon camera tube, then the image at the camera has 20X × 0.75X = 15X magnification.

Example 2: Trinocular Magnification
When imaging a sample through trinoculars, the image is magnified by the objective and the eyepieces in the trinoculars. If using a 20X Nikon objective and Nikon trinoculars with 10X eyepieces, then the image at the eyepieces has 20X × 10X = 200X magnification. Note that the image at the eyepieces does not pass through the camera tube, as shown by the drawing to the right.

Using an Objective with a Microscope from a Different Manufacturer

Magnification is not a fundamental value: it is a derived value, calculated by assuming a specific tube lens focal length. Each microscope manufacturer has adopted a different focal length for their tube lens, as shown by the table to the right. Hence, when combining optical elements from different manufacturers, it is necessary to calculate an effective magnification for the objective, which is then used to calculate the magnification of the system.

The effective magnification of an objective is given by Equation 1:

(Eq. 1)

Here, the Design Magnification is the magnification printed on the objective, f_{Tube Lens in Microscope} is the focal length of the tube lens in the microscope you are using, and f_{Design Tube Lens of Objective} is the tube lens focal length that the objective manufacturer used to calculate the Design Magnification. These focal lengths are given by the table to the right.

Note that Leica, Mitutoyo, Nikon, and Thorlabs use the same tube lens focal length; if combining elements from any of these manufacturers, no conversion is needed. Once the effective objective magnification is calculated, the magnification of the system can be calculated as before.

Example 3: Trinocular Magnification (Different Manufacturers)
When imaging a sample through trinoculars, the image is magnified by the objective and the eyepieces in the trinoculars. This example will use a 20X Olympus objective and Nikon trinoculars with 10X eyepieces.

Following Equation 1 and the table to the right, we calculate the effective magnification of an Olympus objective in a Nikon microscope:

The effective magnification of the Olympus objective is 22.2X and the trinoculars have 10X eyepieces, so the image at the eyepieces has 22.2X × 10X = 222X magnification.

Sample Area When Imaged on a Camera

When imaging a sample with a camera, the dimensions of the sample area are determined by the dimensions of the camera sensor and the system magnification, as shown by Equation 2.

(Eq. 2)

The camera sensor dimensions can be obtained from the manufacturer, while the system magnification is the multiplicative product of the objective magnification and the camera tube magnification (see Example 1). If needed, the objective magnification can be adjusted as shown in Example 3.

As the magnification increases, the resolution improves, but the field of view also decreases. The dependence of the field of view on magnification is shown in the schematic to the right.

Example 4: Sample Area
The dimensions of the camera sensor in Thorlabs' 1501M-USB Scientific Camera are 8.98 mm × 6.71 mm. If this camera is used with the Nikon objective and trinoculars from Example 1, which have a system magnification of 15X, then the image area is:

Sample Area Examples

The images of a mouse kidney below were all acquired using the same objective and the same camera. However, the camera tubes used were different. Read from left to right, they demonstrate that decreasing the camera tube magnification enlarges the field of view at the expense of the size of the details in the image.

Click to Enlarge
Acquired with 1X Camera Tube (Item # WFA4100)

Click to Enlarge
Acquired with 0.75X Camera Tube (Item # WFA4101)

Click to Enlarge
Acquired with 0.5X Camera Tube (Item # WFA4102)

Posted Comments:

alex.maclean (posted 2018-11-15 15:38:36.56)

I am trying to model and then build a confocal microscope using Thorlabs parts. I am trying to select parts that I can model in Zemax and I appreciate that the design of your lenses is a trade secret, but the black box files do not convert into non-sequential models that I can use. It would be very useful if you could provide non-sequential files as well as the sequential ones or if there is some way to convert them that I am missing that would be even better. Many thanks, Alex Maclean

nbayconich (posted 2018-11-29 10:44:07.0)

Thank you for contacting Thorlabs. At the moment zemax does not provide a method to convert a sequential block box model into a non-sequential mode.

hinoki.kuaimu (posted 2018-08-02 17:38:06.747)

Besides a change in magnification ratio, what is the influence on the image of a reduced working distance? I've used your TL2X-SAP super apochromatic lens with a TTL200 working distance of 73mm and got qualitatively sharp images with no noticeable defect (images of live insects in the wild, I have yet to perform experiments with an appropriate test target to better assess the potential image degradation with shorter tube lens working distances).

YLohia (posted 2018-08-27 02:50:51.0)

Hello, thank you for contacting Thorlabs. There are a few considerations when operating at a reduced working distance. As you pointed out, the magnification will change. The system will also produce more aberration/distortion. These two are the side effects with the most noticeable impact. Furthermore, the NA and FOV will also change.

wenzel.jakob (posted 2017-11-30 01:10:38.513)

Hi, your webpage states: "Please note that using a standard tube lens in a scanning configuration will limit the unvignetted field size, since the tube lens must be placed at the telecentric pupil distance from the objective." Could you clarify how this telecentric pupil distance is determined? The "Specs" tab lacks information on this distance values, e.g. for ITL200. Thanks!

tfrisch (posted 2018-03-03 12:28:18.0)

Hello, thank you for contacting Thorlabs. Telecentric Pupil Distance is roughly the focal length when the lens is used in the reverse direction. While using a lens in the reverse direction is not recommended, knowing this value can be useful in modeling a system. A lens is considered telecentric when the focal length falls at the aperture stop of a system, and this places your entrance or exit pupil at infinity (for object or image space telecentricity respectively). The determination of these distances is best done in the modeling software we use to design the lenses (Zemax). We provide black box Zemax files for many of our lens systems as the full prescription is considered proprietary. As for the ITL200, we do not have exact values for many of the specs, but I will reach out to you directly about how to compare against a similar lens, like TTL200.

h.wu (posted 2017-10-03 19:57:11.14)

TTL200 series has a (back) working distance of 148 mm. Could you provide the (front) working distance of TTL200-B? We would like to know the case that a collimated beam is incident from its image plane toward the objective. Thanks.

tfrisch (posted 2017-12-06 11:24:22.0)

Hello, thank you for contacting Thorlabs. These lenses are designed for infinite conjugate use, so you need to be careful if using it in reverse with the infinity space on the opposite side of the lens. Most notably, there will be more spherical aberration as well as vignetting. However, the distance from the opposite focal plane to the housing will be 238.1mm. I will reach out to you to discuss your application further.

shawncasey (posted 2017-08-10 18:27:27.11)

Is the TTL180 actually an Olympus tube lens or a generic equivalent? We have our own tube lens and were wondering if the mount is the same? If so could we purchase it without the lens, so we can more easily adapt our lens to SM2?

tfrisch (posted 2017-08-16 06:24:40.0)

Hello, thank you for contacting Thorlabs. TTL180-A was designed here at Thorlabs. The mount is not just an adapter for a different complete tube lens, it holds the component lenses and spacers, so a different lens would likely not fit. I will reach out to you about adapting your lens to SM2.

h.wu (posted 2017-04-23 14:22:55.03)

Hi, I was very confused the diagram (tube lens schematic) and the description shown in the link the that lenses with external SM2 threads (TTL200-B and TTL200-S8) should be oriented the same as in the diagram. https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=5834 I think that the arrow of TTL200-B in the tube lens schematic should point to the objective (pupil distance) rather than to the image plane because the diagram (tube and scan lens schematic) of the TL200-2P2 shows its arrow pointing to the objective (pupil distance). There is a sentence for TL200-2P2 tube lens in your website. The tube lenses are engraved with an arrow next to an infinity symbol (∞) to indicate which side of the lens should face the objective (infinity space). Thanks

tcampbell (posted 2017-04-24 11:17:37.0)

Response from Tim at Thorlabs: thank you for your feedback. You are correct, the arrow next to the infinity symbol on the tube lens should point toward the objective. We have updated the diagram accordingly.

user (posted 2017-02-15 11:04:34.723)

How do we choose TTL or ITL200? Confusion is that there is no comparison ITL and TTL, and ITL has less information in a specification chart. What is pros and Cons we choose ITL200?

tfrisch (posted 2017-02-17 02:04:09.0)

Hello, thank you for contacting Thorlabs. Nikon manufactures the ITL200, so we do not have a full design comparison against our own TTL200. If you would like to discuss further, please email us at TechSupport@thorlabs.com

hsieh-fu.tsai (posted 2016-12-08 23:50:45.78)

I am interested to build an microscope with this tube lens. However, I wonder how mounting can be done to connect the tube lens to a c-mount camera? Thank you.

tfrisch (posted 2016-12-19 02:21:24.0)

Hello, thank you for contacting Thorlabs. We have an application note on assembling a simple microscope as well as our Do It Yourself (DIY) Cerna series microscope components. I will contact you directly about options. Application note: https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=5835&tabname=Application Cerna series: https://www.thorlabs.com/navigation.cfm?guide_ID=2371

y.tian (posted 2016-10-11 05:29:18.583)

Hello, If I can also use ITL200 in an IR system. Because TL200 2P2 is too expensive that already beyond the budget. What makes such huge price difference?Thanks.

jlow (posted 2016-10-21 04:24:11.0)

Response from Jeremy at Thorlabs: The TL200-2P2 has been optimized for scanning application and it is designed for a wider wavelength range than the ITL200. While it can work for some scanning applications (e.g. if your scan angle is small), it’s not ideal solution. I will contact you directly to discuss further about this

xliay (posted 2016-09-27 13:13:22.31)

Nowadays we are using LSM04-BB as the scan lens and AC508-250-B as the tube lens combination. However, in our stimulated Raman scattering (SRS) microscopy, we found that the Pump beam (780~960 nm) was not perfectly overlapped with the Stokes beam (1031 nm) when the scanning field of view is larger than 60 um using 40X objective. This phenomenon is possibly introduced by the lateral chromatic aberration of our scan relay system because we observed that the FOV is better when using 900 nm than 800 nm. So are there any recommendations of NIR scan relay system from Thorlabs to meet our requirement?

jlow (posted 2016-10-03 05:08:20.0)

Response from Jeremy at Thorlabs: I will contact you directly to discuss about this.

andreas.groeschl (posted 2016-06-06 14:15:41.05)

Dear ladies and gentleman, may question is, why is the Working Distance much less than the focal lenght? Best regards Andreas

besembeson (posted 2016-06-08 09:23:25.0)

Response from Bweh at Thorlabs USA: The focal length is relative to a principal plane of the actual lens element which is inside the housing while the working distance is relative to the external housing edge.

ludoangot (posted 2016-03-17 14:00:38.693)

I also need the ITL200 front focal length, has Nikon provided this information? If not, would it be possible you measure it? Ideally a tick lens model of the ITL200 would be much welcome.

besembeson (posted 2016-03-17 02:59:42.0)

Response from Bweh at Thorlabs USA: Unfortunately Nikon doesn't provide this information.

jesmondhong (posted 2016-03-11 03:32:34.817)

Hi, if i have a lens attached to the camera sensor, should I keep a 148mm from the end of the ITL200 to the front mount of the lens attached to the camera?

besembeson (posted 2016-03-11 11:20:51.0)

Response from Bweh at Thorlabs USA: The ITL200 is your imaging lens so the 148mm should be to the camera sensor. If you have an additional relay lens (which is not typical), then that distance should correspond to the object plane of your relay lens.

pedroalves.dct (posted 2016-02-19 09:33:28.01)

Hello, my purpose is photography. My setup: - Olympus OMd-Em5II camera; - Mitutoyo Mplan 5 and 10x lens. Between the lens and the camera I've an iris diaphragm (from thorlabs) and a raynox dcr250 as tube lens. Between the raynox and the camera I've a extension bellows at 100mm. Well, I'm not happy with the setup and I would like to try the ITL200 instead of the raynox. I need some advices about the distances between the mitutoyo and the ITL200 and the ITL and the camera sensor? Many thanks in advance. Sincerely, Pedro Alves

besembeson (posted 2016-03-03 04:05:05.0)

Response from Bweh at Thorlabs USA: The camera sensor should be about 148mm from the end of the ITL200 and the front of the ITL200 can be between 70-170mm from the end of the objective.

besembeson (posted 2016-03-03 04:05:05.0)

Response from Bweh at Thorlabs USA: The camera sensor should be about 148mm from the end of the ITL200 and the front of the ITL200 can be between 70-170mm from the end of the objective.

gtn75 (posted 2015-11-19 19:55:17.567)

I want to know where are the principal planes of the ITL200.

besembeson (posted 2015-11-20 02:30:45.0)

Response from Bweh at Thorlabs USA: The back focal length is 148mm. We don't have information on the front focal length. I will contact you if Nikon can provide this.

jghimcm (posted 2015-10-27 14:30:16.873)

Can this tube lens used with a Leica Infinity-corrected objective? Thanks!

besembeson (posted 2015-11-05 10:19:41.0)

Response from Shawn at Thorlabs China: It depends on your application. If it involves a monochromatic source, then it should be okay but it may not be very suitable if you have to account for chromatic aberration. This is because Leica (and Zeiss) microscopes have color correction inside their tube lens. They don't correct for chromatic aberrations in the objective. Nikon (and Olympus) have color correction in the their microscope objectives, not in the tube lens.

a.bruni (posted 2015-04-14 08:59:22.95)

dear All, I need a thecnical contact to explane my castom problem. Andrea

jlow (posted 2015-04-15 04:03:15.0)

Response from Jeremy at Thorlabs: You can contact us at techsupport@thorlabs.com to discuss about your application.

user (posted 2015-01-29 19:02:32.153)

The focal length is 148mm from the mounting side, what is it from the other side?

jlow (posted 2015-01-29 02:13:12.0)

Response from Jeremy at Thorlabs: The orientation, distances, and dimension of the tube lens are located in the drawing under "Specs" tab. I am not sure I fully understand your question. Since you did not leave any contact information, can you contact us at techsupport@thorlabs.com to discuss about this further please?

user (posted 2015-01-05 11:30:45.733)

Could you please specify the focal length tolerance on this lens system?

cdaly (posted 2015-01-09 01:37:27.0)

Response from Chris at Thorlabs: The specified tolerance is +/-1%, but it is realistic to expect it to be closer to +/-0.5%.

ieivanov (posted 2014-07-29 19:00:57.11)

You should offer a 2 inch lens tube with internal SM2 threads on one end and set screws for attaching a C-mount on the other end. The lens tube should be the appropriate length, such that when used with the ITL200 lens and the SM2A20 adapter, the sensor of a camera mounted at the C-mount would be the correct focal distance away from the ITL200 lens.

cdaly (posted 2014-08-07 02:53:02.0)

Response from Chris at Thorlabs: Thank you for your suggestion. We will discuss the idea internally and it may be something you see offered as a standard product in the future. We welcome any product ideas which you think would serve to help make our products more useful in your applications.

ikky.shura (posted 2014-06-25 19:07:09.623)

Hi, I purchased this ITL200 lens and it seems to me that the front focal length is more like 250mm by trying to image an obect located at > 10x the measured focal lens (assumed to be infinity). I need to know where is the front focal plane for my experiment and since no zemax file is given it's hard to be convinced. Is this lens being tested by Thorlabs? Has anyone else seen this? Thanks,

jlow (posted 2014-07-21 02:29:59.0)

Response from Jeremy at Thorlabs: The effective focal length of the lens is 200mm and its back focal length is 148mm from the mounting side (smaller aperture side). It will probably be better to measure this with sun light instead.

yangbin (posted 2014-05-21 10:21:08.717)

我是深圳华大基因研究院的光学工程师杨斌，我们想购买型号为ITL200的这个筒镜配合20X的显微镜使用，但我们这个系统总的放大倍数为21.6，不知你们能够告诉在这个倍数时显微物镜与筒镜的距离是多少，或给出筒镜的光学结构参数或Zemax文档让我们自行模拟这个距离，非常感谢。

besembeson (posted 2014-05-22 09:45:20.0)

A response from Bweh Esembeson at Thorlabs USA: Thanks for contacting Thorlabs. Unfortunately we don’t have the Zemax file for this tube lens at this time. If your objective is infinity corrected, then you can calculate the magnification with the tube lens from the ratio of the focal length of the tube lens and that of the objective. The distance between the tube lens and objective can be adjusted (70mm - 170mm for the ITL200) so that all the off-axis rays from object can be brought to the image plane. I will contact you through our China office to know the properties of your objective and help determine the magnification.

pearu.peterson (posted 2014-05-15 14:13:54.85)

SM2AD36 is exactly what I was looking for! Strangely, this component is not listed in the table of adapters, therefore, I could not find it. But thanks for the hint! Pearu

besembeson (posted 2014-05-15 02:38:28.0)

Response from Bweh E at Thorlabs. Thanks for the feedback. The adapter selection guide is a new feature and we are continuously improving this. Based on your comment, we will look into creating more linkage between these products.

pearu.peterson (posted 2014-05-15 12:23:39.65)

Hi, I have 36mm diameter lens (original Nikon back port tube lens) and I wonder if you could provide a tube or any system where to attach such a lens? ITL200 seems to be about the same size (might be too small). Could it fit a 36mm diameter lens? Best regards, Pearu

besembeson (posted 2014-05-15 11:12:18.0)

A Response from Bweh E at Thorlabs in Newton: Thanks for contacting Thorlabs. The ITL200 has an M38x0.5 threaded port which can accommodate the 36mm diameter lens but I am not sure how the thickness of your lens compares with the available space on the ITL200 housing. Besides, we don’t have M38x0.5 retaining rings at this time. We will look into having these as a stock item subsequently. One combination that could possible work for you depending on the thickness of your lens will be the SM2AD36 (http://www.thorlabs.com/thorproduct.cfm?partnumber=SM2AD36) in conjunction with the SM2A20 (http://www.thorlabs.com/thorproduct.cfm?partnumber=SM2A20).

stefano.zoia (posted 2013-09-09 11:46:57.343)

Is this tube lens ITL200 compatible with the Olympus Plan Fluorite objectives? Or, do you have a better solution for these lenses? Thanks

cdaly (posted 2013-09-12 14:15:00.0)

Response from Chris at Thorlabs: Thank you for using our feedback tool. The Olympus objectives are typically intended to be used with a tube lens with a focal length of 180mm. There's not really any particular reason that one cannot be used with a different focal length such as the 200mm ITL200, but it should be noted that the magnification will increase by a factor of 200/180 (10/9).

sdewald (posted 2013-02-18 12:15:19.857)

I need the prescription of the ITL200 tube lens to incorporate it into our system. A .zmx file, please.

cdaly (posted 2013-02-20 20:23:00.0)

Response from Chris at Thorlabs: Thank you for using our web feedback. We will contact you directly about the ITL200.

tcohen (posted 2012-10-18 12:05:00.0)

Response from Tim at Thorlabs to Reto: This is a Nikon tube lens offered for users to be able to design complete microscope systems from our standard components.

fiolkar (posted 2012-10-15 12:35:45.687)

To whom it may concern: Is the ITL200 a tubelens manufactured by Nikkon or is it a Thorlabs design? Best, Reto

jlow (posted 2012-09-13 10:25:00.0)

Response from Jeremy at Thorlabs: The entrance aperture is about 30mm and the exit aperture is about 23.9mm.

ZENJOE.GREEN (posted 2012-09-06 13:31:06.0)

What is the aperature size of the ITL200 tube lens?

jlow (posted 2012-08-15 15:47:00.0)

Response from Jeremy at Thorlabs: The distance between the objective shoulder and the housing of the tube lens should be around 70mm to 170mm for best performance. This distance is also called out in the diagram under the Overview tab.

user (posted 2012-08-14 19:31:26.0)

What is the optimal distance between ITL200 and a Nikon CFI60 objective?

tholste (posted 2012-07-26 16:15:00.0)

A response from Tor at Thorlabs: Thank you for taking the time to contact us. The tube lens is designed for compatibility with the Nikon CFI60 objectives. The performance will be very similar to that of the tube lenses provided with these microscopes. These are apochromatically designed, so they will offer better color-correction as compared to a standard achromatic lens. This is AR-coated for the visible spectrum; we are in the process of measuring the transmittance over the next few weeks, and I will share these data with you as soon as they are available. Please contact techsupport@thorlabs.com if you have additional inquiries.

j.hohlbein1 (posted 2012-07-24 11:47:58.0)

I have the same question (and some more): is the ITL200 similar to the tube lenses found in Olympus or Nikon microscopes? Is it anti-reflection coated? Could you specify the advantages over using achromatic lenses? What is the transmittance? Thanks!

tcohen (posted 2012-04-18 09:33:00.0)

Response from Tim at Thorlabs: Thank you for your feedback. We are looking into this and will update you shortly.

rpalacios (posted 2012-04-13 12:34:44.0)

Is this tube lens compatible with any of the Nikon CFI60 series objectives? Is it the same tube lens found inside the body of the newest Nikon fluorescence microscopes (e.g. TE2000 or Eclipse Ti)?

Tube Lenses for Widefield Imaging

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Effective Focal Lengths Used by Thorlabs, Nikon, Olympus, Leica, Zeiss, and Mitutoyo
Four AR Coatings Available, See Table Below

Thorlabs offers eight infinity-corrected tube lenses for widefield imaging. All TTL series lenses can provide diffraction-limited performance about any single wavelength from 400 to 2000 nm, provided that the tube lens is set to focus on the camera at the target wavelength. Please note that using these lenses for laser scanning will result in vignetting and uneven spot sizes over the FOV; for integration into a telecentric laser scanning system, see the tube lenses below.

The lenses coated for the visible wavelength range (350 - 700 nm) offer good performance at shorter wavelengths (<480 nm) to accommodate applications using 405 nm and 443 nm illumination. The TTL200-B is AR coated for the NIR wavelength range (650 - 1050 nm), making it ideal for NIR fluorescence and NIR DIC imaging. The TTL200-S8 utilizes a broadband MgF₂ single-layer coating with a low transmission roll-off throughout the visible and NIR, with peak transmission centered at 830 nm. See the graphs in the table below for transmission data. All TTL series lenses can be custom coated with either a single layer or a multi-layer AR coating optimized for transmission over a user-specified wavelength range; contact Tech Support for details.

With the exception of the TTL200 and the ITL200, all of these tube lenses are engraved with an arrow next to an infinity symbol (∞) to indicate which side of the lens should face the objective (infinity space). Item #'s TTL200 and ITL200 should be inserted with the M38 x 0.5 threading facing the objective.

Mounting Options
The majority of these lenses feature external SM2 (2.035"-40) threading on both sides that connects to our Ø2" lens tubes and many elements of our 60 mm Cage System. To integrate one of these tube lenses with Thorlabs' Cerna DIY Microscopy Systems, use the SM2M05 lens tube to connect to the WFA4111 Dovetail Adapter (available below).

The TTL200 and ITL200 use external M38 x 0.5 threading for direct compatibility with Nikon and Thorlabs microscopes. This threading can be converted to external SM2 (2.035"-40) threading using the SM2A20 adapter available below. Alternatively, the WFA4111 Dovetail Adapter, also available below, directly accepts a TTL200 or ITL200 tube lens and can integrate it with a Cerna microscope. We also offer the WFA4110 Dovetail Adapter, which is a version of the WFA4111 with the TTL200 tube lens built in.

Item #	Effective Focal Length	Industry Objective Match^a	Working Distance^b,c	Design Wavelength Range^c,d	AR Coating	External Threading	Housing Length
ITL200	200 mm	Thorlabs, Nikon, Leica, Mitutoyo	148 mm	Visible Wavelengths	Visible Wavelengths	M38 x 0.5 Bottom Only	28.0 mm
TTL200	200 mm ± 1%			400 to 750 nm	350 to 750 mm	M38 x 0.5 Bottom Only
TTL200-A				400 to 750 nm	350 to 750 mm	SM2 Top and Bottom
TTL200-S8				400 to 2000 nm	Broadband Single-Layer MgF₂
TTL200-B				650 to 1050 nm	650 to 1050 nm
TTL180-A	180 mm ± 1%	Olympus	130 mm	400 to 750 nm	350 to 750 mm	SM2 Top and Bottom	33.5 mm
TTL165-A	165 mm ± 1%	Zeiss	118 mm	400 to 750 nm			30.9 mm
TTL100-A	100 mm ± 1%	-	60 mm	450 to 750 nm			31.1 mm

Objectives from these companies are designed to provide their specified magnifications when used with a tube lens of this focal length.
Measured from the housing edge to the intermediate image plane.
These lenses are designed to provide diffraction-limited performance from 400 nm to 2000 nm; however, the working distance is valid only over the specified design wavelength range. The lens will need to be refocused when used at other wavelengths. Once refocused for a new center wavelength, the performance will be diffraction limited for some finite bandwidth around that wavelength. Nominal bandwidth, working distance, and performance can be estimated using the Zemax black box files. The axial color plots and performance data on the Specs tab can be used for guidance when adjusting the working distance.
The glass in these tube lenses is highly absorptive below the lower limit of the stated range.

Based on your currency / country selection, your order will ship from Newton, New Jersey

+1 Qty Docs Part Number - Universal Price Available

ITL200 Tube Lens, f = 200 mm, External M38 x 0.5 Threads

$482.23

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TTL200 Tube Lens, f = 200 mm, ARC: 350-700 nm, External M38 x 0.5 Threads

$482.23

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TTL200-A Customer Inspired! Tube Lens, f = 200 mm, ARC: 350-700 nm, External SM2 Threads

$482.23

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TTL200-S8 Customer Inspired! Tube Lens, f = 200 mm, Broadband MgF₂ Coating, External SM2 Threads

$482.23

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TTL200-B Customer Inspired! Tube Lens, f = 200 mm, ARC: 650-1050 nm, External SM2 Threads

$482.23

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TTL180-A Customer Inspired! Tube Lens, f = 180 mm, ARC: 350-700 nm, External SM2 Threads

$731.30

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TTL165-A Customer Inspired! Tube Lens, f = 165 mm, ARC: 350-700 nm, External SM2 Threads

$731.30

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TTL100-A Customer Inspired! Tube Lens, f = 100 mm, ARC: 350-700 nm, External SM2 Threads

$818.85

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Telecentric Tube Lenses for Laser Scanning and Widefield Imaging

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Matched Track Length Between Different Focal Lengths

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The TL600-A, TL400-A, TL300-A, and TTL200MP tube lenses are designed to have the same track length, defined as the distance between the image plane of the tube lens and the entrance pupil of the objective.

200 mm Effective Focal Length Used by Thorlabs, Nikon, Leica, and Mitutoyo
300 mm, 400 mm, and 600 mm Effective Focal Lengths for Increased Magnification in Standard Systems
Telecentric Design

These infinity-corrected tube lenses feature a telecentric design appropriate for both laser scanning and widefield imaging applications. Our laser scanning tube lenses with a wavelength range from 400 to 700 nm or 450 to 1100 nm can be paired with our SL50-CLS2 (450 - 1100 nm) scan lens to create a telecentric system. Similarly, the TL200-2P2 and TL200-3P are designed to be used with our SL50-2P2 (680 - 1600 nm) or SL50-3P (900 - 1900 nm) scan lenses, respectively. Due to the extended wavelength range of its AR coating, the TTL200MP can be paired with any of these three scan lenses.

The TL600-A, TL400-A, TL300-A, and TTL200MP tube lenses are designed with an identical nominal track length of 420 mm, allowing tube lenses of different focal lengths to be interchanged without realigning the imaging device or objective.

All of these lenses can be custom coated with either a single-layer or a multi-layer AR coating optimized for transmission over a user-specified wavelength range between 400 nm and 2000 nm; contact Tech Support for details. These tube lenses are engraved with an arrow next to an infinity symbol (∞) to indicate which side of the lens should face the objective (infinity space).

Mounting Options
These tube lenses feature external SM2 (2.035"-40) threading on one or both sides that connects to our Ø2" lens tubes and many elements of our 60 mm Cage System. To integrate these tube lenses with Thorlabs' Cerna DIY Microscopy Systems, use the SM2M05 lens tube to connect to the WFA4111 Dovetail Adapter (available below).

Item #	Effective Focal Length	Industry Objective Match^a	Working Distance^b,c	Design Wavelength Range^d	AR Coating	Threading	Housing Length
TL600-A	600 mm ± 1%	-	91 mm	400 to 700 nm	400 to 700 nm	External SM2, Top and Bottom	205.7 mm
TL400-A	400 mm ± 1%	-
TL300-A	300 mm ± 1%	-
TTL200MP	200 mm ± 1%	Thorlabs, Nikon, Leica, Mitutoyo	148 mm	400 to 2000 nm	400 to 1300 nm		44.1 mm
TL200-CLS2			180.9 mm	450 to 1100 nm	450 to 1100 nm	External SM2 (Bottom), Internal SM2 (Top)	41.6 mm
TL200-2P2				680 to 1600 nm	680 to 1600 nm
TL200-3P				900 to 1900 nm	900 to 1900 nm

These companies offer objectives designed for use with the stated tube lens focal length.
Measured from the housing edge to the intermediate image plane.
The working distance is valid over the design wavelength range, and the lens will need to be refocused when used at other wavelengths. The axial color plots and performance data on the Specs tab can be used for guidance when adjusting the working distance.
The glass in these tube lenses is highly absorptive below the lower limit of the stated range.

Mechanical Adapters for TTL200 and ITL200 Tube Lenses

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Click to Enlarge
A WFA4111 can be used to integrate a TTL200 tube lens into a custom epi-illumination module on a DIY Cerna Microscope.

Modular Tube Lenses for Cerna Microscopes

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The WFA4111 adapter allows M38 x 0.5-threaded tube lenses to be easily integrated with Cerna microscopes and SM2-threaded components.

Easily Integrate Tube Lenses with Thorlabs' Construction Systems
WFA4111: D1N Male Dovetail for Using Tube Lenses in Cerna DIY Systems and Microscopes
SM2A20: External SM2 Threading for Compatibility with SM2 Lens Tubes

Thorlabs offers two styles of adapters for use with the externally M38 x 0.5-threaded TTL200 and ITL200 tube lenses, allowing them to be integrated with Thorlabs' SM2 lens tube systems and Cerna DIY Microscopy Platform. Our other tube lenses already have external SM2 (2.035"-40) threads.

Our WFA4111 Dovetail Adapter directly accepts the TTL200 and ITL200. Alternatively, external SM2 threads on the top of the adapter allow externally SM2-threaded lenses to be connected via an SM2M05 lens tube. The bottom of the adapter features a male D1N dovetail, making it compatible with our DIY Cerna systems. The SM2 threads on top can also be used to integrate user-designed camera tubes constructed from SM2-threaded lens tubes.

The SM2A20 allows the TTL200 and ITL200 to be easily converted to SM2 threading, enabling the construction of an optical system consisting of a scan lens and a tube lens using Thorlabs' standard SM2 lens tube components and the SM2-threaded GCM102(/M) 2D galvo mounting adapter. We also offer SM2-threaded adapters for common objective threads.

The SM38RR retaining ring can be used to lock the tube lens in place when using either adapter. We also offer the WFA4110 Dovetail Adapter, a version of the WFA4111 adapter that includes the TTL200 tube lens.

View All »Matching Part Numbers

Infinity-Corrected Tube Lenses

Features

Tube Lenses for Widefield Imaging

Tube Lenses for Laser Scanning and Widefield Imaging

Magnification and Sample Area Calculations

Magnification

Using an Objective with a Microscope from a Different Manufacturer

Sample Area When Imaged on a Camera

Sample Area Examples

Tube Lenses for Widefield Imaging

Telecentric Tube Lenses for Laser Scanning and Widefield Imaging

Mechanical Adapters for TTL200 and ITL200 Tube Lenses