Long Working Distance Objectives


  • Objectives for UV, Visible, or NIR Light
  • 5X, 7.5X, 10X, 20X, 50X, or 100X Magnification
  • Ideal for Machine Vision Applications
  • Infinity-Corrected Design

MY5X-802

5X Objective
436 nm - 656 nm

MY100X-806

100X Objective
436 nm - 656 nm

MY50X-825

50X Objective
480 nm - 1800 nm

LMUL-10X-UVB

10X Objective
240 nm - 360 nm

Related Items


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Objective Lens Selection Guide
Objectives
Super Apochromatic Microscope Objectives
Microscopy Objectives, Dry

Microscopy Objectives, Oil Immersion
Physiology Objectives, Water Dipping or Immersion
Phase Contrast Objectives
Long Working Distance Objectives
Reflective Microscopy Objectives
UV Focusing Objectives
VIS and NIR Focusing Objectives
Scan Lenses and Tube Lenses
Scan Lenses
F-Theta Scan Lenses
Infinity-Corrected Tube Lenses
Zemax Files
Click on the red Document icon next to the item numbers below to access the Zemax file download. Our entire Zemax Catalog is also available.

Click for Details

This diagram illustrates the labels, working distance, and parfocal distance. The format of the engraved specifications will vary between objectives and manufacturers. (See the Objective Tutorial tab for more information about microscope objective types.)

Features

  • Long Working Distance Ideal for Machine Vision Applications
  • Infinity-Corrected Options for UV, Visible, or NIR Wavelengths
  • Designed for a Tube Lens Focal Length of 200 mm
  • M26 x 0.706 Threading

Thorlabs offers long working distance M Plan objectives for ultraviolet (UV), visible, or near-infrared (NIR) wavelength ranges. These objectives are designed for use with a tube lens focal length of 200 mm and are ideal for machine vision applications or applications that require a significant distance between the objective lens and the object. See the Specs tab for details on each of the objectives available here.

Each objective housing is engraved with key specifications including the magnification, the numerical aperture, and an infinity symbol noting that it is infinity corrected; see the image to the right. The housings have external M26 x 0.706 threads; to convert M26 x 0.706 threads to M32 x 0.75 threads, we offer the M32M26S thread adapter.

All of the objectives found on this page have a parfocal length of 95 mm (see the Specs tab for complete specifications). To use them alongside other manufacturer standards, such as Nikon objectives with a 60 mm parfocal length, we offer parfocal length extenders. For instance, the PLE351 Extender can be used to increase the parfocal length of a Nikon objective from 60 mm to 95 mm.

These objectives are designed to be used without a cover glass and do not feature a correction collar. Imaging through a cover glass may cause spherical aberrations in an image, depending on the numerical aperture of the objective. See the Objective Tutorial tab for more on how a cover glass may impact performance. For biological applications where imaging through cover glasses is required, consider our super apochromatic objectives.

Item # Wavelength
Range
Ma WD EFL NA EPb Spot
Sizec
Typical Transmission OFN PFLd Design Tube Lens Focal Lengthe AR Coating
Reflectance
Pulsed
Damage Threshold
Objective
Threading
Thorlabs Long Working Distance, Achromatic, MicroSpot® UV Focusing Objectives
LMUL-10X-UVB 240 - 360 nm 10X 20.0 mm 20 mm 0.25 10.0 mm 1.4 µm Icon
Raw Data
24 95.0 mm 200 mm <1.5%
per Surface
(240 - 360 nm)f
5.0 J/cm2
(355 nm, 10 ns,20 Hz, Ø0.342 mm)
M26 x 0.706;
5 mm Depth
LMUL-20X-UVB 20X 15.3 mm 10 mm 0.36 7.2 mm 1 µm Icon
Raw Data
LMUL-50X-UVB 50X 12.0 mm 4 mm 0.42 3.4 mm 0.7 µm Icon
Raw Data
Mitutoyo Long Working Distance Apochromatic Objectives
MY5X-802
436 - 656 nm 5X 34.0 mm 40 mm 0.14 11.2 mm 2.5 µm Transmission Icon 24 95.0 mm 200 mm Proprietary Proprietary M26 x 0.706;
5 mm Depth
MY7X-807 7.5X 35.0 mm 27 mm 0.21 11.2 mm 1.7 µm Proprietary
MY10X-803 10X 34.0 mm 20 mm 0.28 11.2 mm 1.3 µm Transmission Icon
MY20X-804 20X 20.0 mm 10 mm 0.42 8.4 mm 0.8 µm Transmission Icon
MY50X-805 50X 13.0 mm 4 mm 0.55 4.4 mm 0.6 µm Transmission Icon
MY100X-806 100X 6.0 mm 2 mm 0.70 2.8 mm 0.5 µm Transmission Icon
Mitutoyo Long Working Distance Apochromatic NIR Objectives
MY5X-822 480 - 1800 nm 5X 37.5 mm 40 mm 0.14 11.2 mm 2.5 µm Transmission Icon 24 95.0 mm 200 mm Proprietary Proprietary M26 x 0.706;
5 mm Depth
MY10X-823 10X 30.5 mm 20 mm 0.26 10.4 mm 1.3 µm Transmission Icon
MY20X-824 20X 20.0 mm 10 mm 0.40 8.0 mm 0.9 µm Transmission Icon
MY50X-826 50X 17.0 mm 4 mm 0.42 3.4 mm 0.8 µm Transmission Icon
  • When Used with a 200 mm Focal Length Tube Lens
  • Entrance pupil diameter (EP) is defined at the back aperture of the objective and calculated as EP=2*NA*EFL.
  • Spot size is calculated assuming the entrance pupil is filled and the input beam profile is Gaussian.
  • This dimension is shown in the diagram to the right.
  • For information on compatibility between tube lenses and objectives, see the Magnification & FOV tab.
  • Using these objectives outside of their AR coating range is not recommended because of surface reflections that can create ghost images and significantly reduce the overall transmission through the optic.

M = Magnification
WD = Working Distance
EFL = Effective Focal Length
NA = Numerical Aperture

EP = Entrance Pupil Diameter
OFN = Optical Field Number
PFL = Parfocal Length

Diagram Showing General Objective Dimensions
Chromatic Aberration Correction per ISO Standard 19012-2
Objective Class Common Abbreviations Axial Focal Shift Tolerancesa
Achromat ACH, ACHRO, ACHROMAT C' - δF'| ≤ 2 x δob
Semiapochromat
(or Fluorite)
SEMIAPO, FL, FLU C' - δF'| ≤ 2 x δob
F' - δe| ≤ 2.5 x δob
C' - δe| ≤ 2.5 x δob
Apochromat APO C' - δF'| ≤ 2 x δob
F' - δe| ≤ δob
C' - δe| ≤ δob
Super Apochromat SAPO See Footnote b
  • Measured as the difference of the focal length (δ) between two of the following wavelengths: 479.99 nm (F'-line), 546.07 nm (e-line), and 643.85 nm (C'-line), compared to the theoretical focal length δob. The δob = (n*λe)/(2*NA^2), where n is the refractive index of the medium in object space, NA is the numerical aperture of the objective, and λe is 479.99 nm (e-line).
  • Super apochromats currently are not defined under ISO 19012-2: Microscopes -- Designation of Microscope Objectives -- Chromatic Correction.

Parts of a Microscope Objective
Click on each label for more details.

Parts of a Microscope Objective Thread Depth Shoulder Correction Collar Label Area Magnification Identifier Immersion Identifier Iris Ring Parfocal Length Text Working Distance Text Retraction Stopper

This microscope objective serves only as an example. The features noted above with an asterisk may not be present on all objectives; they may be added, relocated, or removed from objectives based on the part's needs and intended application space.

Objective Tutorial

This tutorial describes features and markings of objectives and what they tell users about an objective's performance.

Objective Class and Aberration Correction

Objectives are commonly divided by their class. An objective's class creates a shorthand for users to know how the objective is corrected for imaging aberrations. There are two types of aberration corrections that are specified by objective class: field curvature and chromatic aberration.

Field curvature (or Petzval curvature) describes the case where an objective's plane of focus is a curved spherical surface. This aberration makes widefield imaging or laser scanning difficult, as the corners of an image will fall out of focus when focusing on the center. If an objective's class begins with "Plan", it will be corrected to have a flat plane of focus.

Images can also exhibit chromatic aberrations, where colors originating from one point are not focused to a single point. To strike a balance between an objective's performance and the complexity of its design, some objectives are corrected for these aberrations at a finite number of target wavelengths.

The four common objective classes are shown in the table to the right; only three are defined under the International Organization for Standards ISO 19012-2: Microscopes -- Designation of Microscope Objectives -- Chromatic Correction

Immersion Methods
Click on each image for more details.

Immersion Methods Dry Dipping Immersion

Objectives can be divided by what medium they are designed to image through. Dry objectives are used in air; whereas dipping and immersion objectives are designed to operate with a fluid between the objective and the front element of the sample.

Glossary of Terms
Back Focal Length and Infinity Correction The back focal length defines the location of the intermediate image plane. Most modern objectives will have this plane at infinity, known as infinity correction, and will signify this with an infinity symbol (∞). Infinity-corrected objectives are designed to be used with a tube lens between the objective and eyepiece. Along with increasing intercompatibility between microscope systems, having this infinity-corrected space between the objective and tube lens allows for additional modules (like beamsplitters, filters, or parfocal length extenders) to be placed in the beam path.

Note that older objectives and some specialty objectives may have been designed with finite back focal lengths. In their inception, finite back focal length objectives were meant to interface directly with the objective's eyepiece.
Entrance Aperture This measurement corresponds to the appropriate beam diameter one should use to allow the objective to function properly.

Entrance Aperture = 2 × NA × Effective Focal Length
Field Number and Field of View The field number corresponds to the diameter of the field of view in object space (in millimeters) multiplied by the objective's magnification.

Field Number = Field of View Diameter × Magnification
Magnification The magnification (M) of an objective is the lens tube focal length (L) divided by the objective's effective focal length (F). Effective focal length is sometimes abbreviated EFL: 

M = L / EFL .

The total magnification of the system is the magnification of the objective multiplied by the magnification of the eyepiece or camera tube. The specified magnification on the microscope objective housing is accurate as long as the objective is used with a compatible tube lens focal length. Objectives will have a colored ring around their body to signify their magnification. This is fairly consistent across manufacturers; see the Parts of a Microscope section for more details.
Numerical Aperture (NA) Numerical aperture, a measure of the acceptance angle of an objective, is a dimensionless quantity. It is commonly expressed as:

NA = ni × sinθa

where θa is the maximum 1/2 acceptance angle of the objective, and ni is the index of refraction of the immersion medium. This medium is typically air, but may also be water, oil, or other substances.
Working Distance
The working distance, often abbreviated WD, is the distance between the front element of the objective and the top of the specimen (in the case of objectives that are intended to be used without a cover glass) or top of the cover glass, depending on the design of the objective. The cover glass thickness specification engraved on the objective designates whether a cover glass should be used.

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Threading allows an objective to be mounted to a nosepiece or turret. Objectives can have a number of different thread pitches; Thorlabs offers a selection of microscope thread adapters to facilitate mounting objectives in different systems.

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The shoulder is located at the base of the objective threading and marks the beginning of the exposed objective body when it is fully threaded into a nosepiece or other objective mount.

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A cover glass, or coverslip, is a small, thin sheet of glass that can be placed on a wet sample to create a flat surface to image across.

The most common, a standard #1.5 cover glass, is designed to be 0.17 mm thick. Due to variance in the manufacturing process the actual thickness may be different. The correction collar present on select objectives is used to compensate for cover glasses of different thickness by adjusting the relative position of internal optical elements. Note that many objectives do not have a variable cover glass correction, in which case the objectives have no correction collar. For example, an objective could be designed for use with only a #1.5 cover glass. This collar may also be located near the bottom of the objective, instead of the top as shown in the diagram.


Click to Enlarge

The graph above shows the magnitude of spherical aberration versus the thickness of the coverslip used for 632.8 nm light. For the typical coverslip thickness of 0.17 mm, the spherical aberration caused by the coverslip does not exceed the diffraction-limited aberration for objectives with NA up to 0.40.

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The labeling area for an objective usually falls in the middle of the objective body. The labeling found here is dictated by ISO 8578: Microscopes -- Marking of Objectives and Eyepieces, but not all manufacturers adhere strictly to this standard. Generally, one can expect to find the following information in this area:

  • Branding/Manufacturer
  • Aberration Correction (Objective Class)
  • Magnification
  • Numerical Aperture (NA)
  • Back Focal Length (Infinity Correction)
  • Suitable Cover Glass Thicknesses
  • Working Distance

Additionally, the objective label area may include the objective's specified wavelength range, specialty features or design properties, and more. The exact location and size of each and any of these elements can vary. 

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In order to facilitate fast identification, nearly all microscope objectives have a colored ring that circumscribes the body. A breakdown of what magnification each color signifies is given in the table below.

Magnification Identifier Color Ring
Codes per ISO 8578
Black 1X or 1.25X Light Green 16X or 20X
Grey 1.6X or 2X Dark Green 25X or 32X
Brown 2.5X or 3.2X Light Blue 40X or 50X
Red 4X or 5X Dark Blue 63X or 80X
Orange 6.3X or 8X White 100X, 125X, or 160X
Yellow 10X or 12.5X

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Immersion Identifier Color Ring Codes
per ISO 8578
None Dry
Black Oil
White Water
Orange Glycerol
Red Others

If an objective is used for water dipping, water immersion, or oil immersion, a second colored ring may be placed beneath the magnification identifier. If the objective is designed to be used with water, this ring will be white. If the objective is designed to be used with oil, this ring will be black. Dry objectives lack this identifier ring entirely. See the table to the right for a complete list of immersion identifiers.

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Objectives that feature a built-in iris diaphragm are ideal for darkfield microscopy. The iris diaphragm is designed to be partially closed during darkfield microscopy in order to preserve the darkness of the background. This is absolutely necessary for high numerical aperture (above NA = 1.2) oil immersion objectives when using an oil immersion darkfield condenser. For ordinary brightfield observations, the iris diaphragm should be left fully open.

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Also referred to as the parfocal distance, this is the length from the shoulder to the top of the specimen (in the case of objectives that are intended to be used without a cover glass) or the top of the cover glass. When working with multiple objectives in a turret, it is helpful if all of the parfocal distances are identical, so little refocusing will be required when switching between objectives. Thorlabs offers parfocal length extenders for instances in which the parfocal length needs to be increased.

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The working distance, often abbreviated WD, is the distance between the front element of the objective and the top of the specimen (in the case of objectives that are intended to be used without a cover glass) or top of the cover glass. The cover glass thickness specification engraved on the objective designates whether a cover glass should be used.

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Objectives with very small working distances may have a retraction stopper incorporated into the tip. This is a spring-loaded section which compresses to limit the force of impact in the event of an unintended collision with the sample.

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Immersion Identifier Color Ring Codes
per ISO 8578
None Dry
Black Oil
White Water
Orange Glycerol
Red Others

Dry objectives are designed to have an air gap between the objective and the specimen.

Objectives following ISO 8578: Microscopes -- Marking of Objectives and Eyepieces will be labeled with an identifier ring to tell the user what immersion fluid the objective is designed to be used with; a list of ring colors can be found in the table to the right.

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Immersion Identifier Color Ring Codes
per ISO 8578
None Dry
Black Oil
White Water
Orange Glycerol
Red Others

Dipping objectives are designed to correct for the aberrations introduced by the specimen being submerged in an immersion fluid. The tip of the objective is either dipped or entirely submerged into the fluid.

Objectives following ISO 8578: Microscopes -- Marking of Objectives and Eyepieces will be labeled with an identifier ring to tell the user what immersion fluid the objective is designed to be used with; a list of ring colors can be found in the table to the right.

Close

 

Immersion Identifier Color Ring Codes
per ISO 8578
None Dry
Black Oil
White Water
Orange Glycerol
Red Others

Immersion objectives are similar to water-dipping objectives; however, in this case the sample is under a cover glass. A drop of fluid is then added to the top of the cover glass, and the tip of the objective is brought into contact with the fluid. Often, immersion objectives feature a correction collar to adjust for cover glasses with different thicknesses. Immersion fluids include water, oil (such as MOIL-30), and glycerol.

Using an immersion fluid with a high refractive index allows objectives to achieve numerical apertures greater than 1.0. However, if an immersion objective is used without the fluid present, the image quality will be very low. Objectives following ISO 8578: Microscopes -- Marking of Objectives and Eyepieces will be labeled with an identifier ring to tell the user what immersion fluid the objective is designed to be used with; a list of ring colors can be found in the table above.

Widefield Viewing Optical Path
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.
Magnification & FOV Calculator
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:

Equation 1 (Eq. 1)

Here, the Design Magnification is the magnification printed on the objective, fTube Lens in Microscope is the focal length of the tube lens in the microscope you are using, and fDesign 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:

Equation 2

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.


Image Area on Camera

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.

Equation 5 (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:

Equation 6

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.

Image with 1X Camera Tube
Click to Enlarge

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

Acquired with 0.75X Camera Tube (Item # WFA4101)
Image with 1X Camera Tube
Click to Enlarge

Acquired with 0.5X Camera Tube (Item # WFA4102)

Posted Comments:
Verena Buehler  (posted 2020-08-14 11:39:42.21)
Hello Thorlabs Team, I was wondering why you do not offer a black box file for this popular Objective? It would be helpful to simulate in Zemax how or if a individual setup works with it. Please contact me for any helpful information. Kind regards, Verena Buehler
nbayconich  (posted 2020-08-17 10:10:52.0)
Thank you for your feedback. Our vendor Mitutoyo unfortunately does not provide us with zemax models for these objectives. I will reach out to you directly to discuss your application.
Shankar MENON  (posted 2020-06-22 17:43:38.59)
Is it possible to get objective AR coated for high transmission at a specific wavelength?
YLohia  (posted 2020-06-23 09:22:58.0)
Hello, thank you for contacting Thorlabs. Custom optics can be requested by emailing techsupport@thorlabs.com. We will reach out to you directly to discuss the possibility of offering this.
user  (posted 2020-04-07 10:43:42.103)
Concerning Mitutoyo NIR objectives, do you have any info how much the focal length changes (e.g. at 1550 [nm]) respective to the visible range? It would typically be helpful to know if it is more or less than the Rayleigh range.
llamb  (posted 2020-04-13 09:54:47.0)
Thank you for your feedback. The focal shift can be up to 15 µm for wavelengths in the 1100-1600 nm range. More detailed information could be provided after discussing your application further. I see that your contact information was not provided, so feel free to reach out to techsupport@thorlabs.com if you would like further information.
Clara Rittmann  (posted 2019-10-17 10:12:14.72)
Hi, I do not understand why the effective focal length can be significantly smaller than the working distance at the long distance working objectives such as the MY50x-825. How is that achieved? I just do not feel comfortable about using optics that I do not fully understand. Thanks!
YLohia  (posted 2019-10-17 11:30:33.0)
Hello Clara, the EFL is defined as the distance between the principal plane and the focus spot, in order provide users a number to perform calculations for field of view, focused spot size, etc. The principle plane does not necessarily have to be within the length of the objective itself and, in this case, is specifically designed to be outside of it in order to achieve a long working distance.
user  (posted 2019-02-03 23:59:26.797)
Have you considered, as e.g. order on demand item, also to supply the rest of the Mitutoyo Plan App line e.g. the HR Plan Apo series.
nbayconich  (posted 2019-02-06 03:29:34.0)
Thank you for contacting Thorlabs. At the moment we do not have plans to release additional Mitutoyo objectives but we can provide special orders upon request. Please contact techsupport@thorlabs.com regarding any special order requests.
np  (posted 2018-03-26 20:46:08.447)
Can you please tell what is the location of the back focal plane of the MY100X-806 relative to the end of the lens?
nbayconich  (posted 2018-03-31 03:51:36.0)
Thank you for contacting Thorlabs. Information such as the back focal plane location is typically proprietary for most objective lens manufacturers and can only provide certain specifications to particular end users. I will reach out to you directly to discuss your application and provide more information if possible.
maciej.koperski  (posted 2017-10-04 11:50:15.6)
Dear Sir/Madam Could you please provide information, in which spectral range can this objective be used? Could you perhaps show transmission spectra? With best regards, Maciej Koperski
nbayconich  (posted 2017-10-12 10:36:40.0)
Thank you for contacting Thorlabs. Mitutoyo's objective transmission spectrum is proprietary information. The recommended performance range for these objectives is between 450nm - 650nm. I will reach out to you directly.

Thorlabs Achromatic, MicroSpot® UV Focusing Objectives

Percent Focal Length Shift
Click to Enlarge

Click Here for Raw Data
  • AR Coated for 240 - 360 nm
  • Ideal for Laser Focusing and UV Imaging Applications
  • Diffraction-Limited Performance
  • 10X, 20X, or 50X Magnification

Thorlabs MicroSpot objectives provide long working distances while keeping axial focal shift low. Their optical design is chromatically optimized in the UV wavelength range. Diffraction-limited performance is guaranteed over the entire clear aperture. These objectives are ideal for laser cutting, surgical laser focusing, and spectrometry applications. They can also be used for scanning and micro-imaging applications like brightfield imaging under narrowband, UV laser illumination. Each objective is shipped in an objective case comprised of an OC2M26 lid and an OC24 canister.

Each objective is engraved with its class, magnification, numerical aperture, wavelength range, a zero (noting that it is to be used to image a sample without a cover glass) and optical field number. For an explanation of the defining properties of these objectives, please see the Objective Tutorial tab. 

Thorlabs can provide these objectives with custom AR coatings on request by contacting Tech Support; options include broadband NUV (325 nm - 500 nm), dual band (266 and 532 nm), and laser line (248 nm, 266 nm, 355 nm, or 532 nm). We also offer additional MicroSpot objectives for laser-focusing applications in the UV as well as visible and near-IR wavelengths.

Item # Wavelength
Range
Ma WD EFL NA EPb Spot 
Sizec
Typical Transmission OFN PFL AR Coating
Reflectanced
Pulsed
Damage Threshold
Objective
Threading
LMUL-10X-UVB 240 - 360 nm 10X 20.0 mm 20 mm 0.25 10.0 mm 1.4 µm Icon
Raw Data
24 95.0 mm <1.5% per Surface
(240 - 360 nm)
5.0 J/cm2
(355 nm, 10 ns,
20 Hz, Ø0.342 mm)
M26 x 0.706;
5 mm Depth
LMUL-20X-UVB 20X 15.3 mm 10 mm 0.36 7.2 mm 1.0 µm Icon
Raw Data
LMUL-50X-UVB 50X 12.0 mm 4 mm 0.42 3.4 mm 0.7 µm Icon
Raw Data
  • When Used with a 200 mm Focal Length Tube Lens
  • Entrance pupil diameter (EP) is defined at the back aperture of the objective and calculated as EP=2*NA*EFL.
  • Spot size is calculated at the center wavelength, assuming the entrance pupil is filled and the input beam profile is Gaussian.
  • Using these objectives outside of their AR coating range is not recommended because of surface reflections that can create ghost images and significantly reduce the overall transmission through the optic.

M = Magnification
WD = Working Distance
EFL = Effective Focal Length
PFL = Parfocal Length

NA = Numerical Aperture
EP = Entrance Pupil Diameter
OFN = Optical Field Number

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
LMUL-10X-UVB Support Documentation
LMUL-10X-UVBLong Working Distance MicroSpot Focusing Objective, 10X, 240 - 360 nm, NA = 0.25
$8,858.52
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LMUL-20X-UVB Support Documentation
LMUL-20X-UVBCustomer Inspired! Long Working Distance MicroSpot Focusing Objective, 20X, 240 - 360 nm, NA = 0.36
$12,723.37
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LMUL-50X-UVB Support Documentation
LMUL-50X-UVBLong Working Distance MicroSpot Focusing Objective, 50X, 240 - 360 nm, NA = 0.42
$12,905.90
Lead Time

Mitutoyo Apochromatic Objectives

  • For Use from 436 nm to 656 nm
  • Suitable for Brightfield Observation
  • 5X, 7.5X, 10X, 20X, 50X, or 100X Magnification

Thorlabs offers Mitutoyo Plan Apochromat Objectives with 5X, 7.5X, 10X, 20X, 50X, or 100X magnification. They feature a flat field of focus and chromatic correction in the visible range. The long working distance provides a wide space between the lens surface and the object making them ideal for machine vision applications. Each objective is engraved with its class, magnification, numerical aperture, a zero (noting that it is to be used to image a sample without a cover glass) and the tube lens focal length for which the specified magnification is valid. For an explanation of the defining properties of these objectives, please see the Objective Tutorial tab. If the case shipped with each of these objectives is lost or broken, Thorlabs offers an objective case (item #s OC2M26 and OC24) that can be used as a replacement.

Item # Wavelength Range Ma WD EFL NA EPb Spot
Sizec
Typical Transmission OFN PFL AR Coating
Reflectance
Pulsed
Damage Threshold
Objective
Threading
MY5X-802 436 - 656 nm 5X 34.0 mm 40 mm 0.14 11.2 mm 2.5 µm Transmission Icon 24 95 mm Not Available Not Available M26 x 0.706;
5 mm Depth
MY7X-807 7.5X 35.0 mm 26.7 mm 0.21 11.2 mm 1.7 µm Proprietary
MY10X-803 10X 34.0 mm 20 mm 0.28 11.2 mm 1.3 µm Transmission Icon
MY20X-804 20X 20.0 mm 10 mm 0.42 8.4 mm 0.8 µm Transmission Icon
MY50X-805 50X 13.0 mm 4 mm 0.55 4.4 mm 0.6 µm Transmission Icon
MY100X-806 100X 6.0 mm 2 mm 0.70 2.8 mm 0.5 µm Transmission Icon
  • When Used with a 200 mm Focal Length Tube Lens
  • Entrance pupil diameter (EP) is defined at the back aperture of the objective and calculated as EP=2*NA*EFL.
  • Spot size is calculated at 550 nm, assuming the entrance pupil is filled and the input beam profile is Gaussian.

M = Magnification
WD = Working Distance
EFL = Effective Focal Length
PFL = Parfocal Length

NA = Numerical Aperture
EP = Entrance Pupil Diameter
OFN = Optical Field Number

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
MY5X-802 Support Documentation
MY5X-802Customer Inspired! 5X Mitutoyo Plan Apochromat Objective, 436 - 656 nm, 0.14 NA, 34 mm WD
$752.08
5-8 Days
MY7X-807 Support Documentation
MY7X-807Customer Inspired! 7.5X Mitutoyo Plan Apochromat Objective, 436 - 656 nm, 0.21 NA, 35 mm WD
$1,380.20
Today
MY10X-803 Support Documentation
MY10X-803Customer Inspired! 10X Mitutoyo Plan Apochromat Objective, 436 - 656 nm, 0.28 NA, 34 mm WD
$944.69
Today
MY20X-804 Support Documentation
MY20X-804Customer Inspired! 20X Mitutoyo Plan Apochromat Objective, 436 - 656 nm, 0.42 NA, 20 mm WD
$2,224.83
Today
MY50X-805 Support Documentation
MY50X-805Customer Inspired! 50X Mitutoyo Plan Apochromat Objective, 436 - 656 nm, 0.55 NA, 13 mm WD
$2,770.70
5-8 Days
MY100X-806 Support Documentation
MY100X-806Customer Inspired! 100X Mitutoyo Plan Apochromat Objective, 436 - 656 nm, 0.70 NA, 6 mm WD
$3,751.70
Today

Mitutoyo Apochromatic NIR Objectives

  • For Use from 480 nm to 1800 nm
  • Suitable for Brightfield Observation and Laser Focusing
  • 5X, 10X, 20X, or 50X Magnification

Thorlabs offers Mitutoyo Plan Apochromat Near-Infrared (NIR) Objectives with 5X, 10X, 20X, or 50X magnification. They feature a flat field of focus and chromatic correction in the visible range with extended transmission to 1800 nm. The long working distance provides a wide space making them ideal for machine vision applications or laser focusing. Each objective is engraved with its class, magnification, numerical aperture, a zero (noting that it is to be used to image a sample without a cover glass) and the tube lens focal length for which the specified magnification is valid. For an explanation of the defining properties of these objectives, please see the Objective Tutorial tab. If the case shipped with each of these objectives is lost or broken, Thorlabs offers an objective case (item #s OC2M26 and OC24) that can be used as a replacement.


Item # Wavelength Range Ma WD EFL NA EPb Spot
Sizec
Typical Transmission OFN PFL AR Coating
Reflectance
Pulsed
Damage Threshold
Objective
Threading
MY5X-822 480 - 1800 nm 5X 37.5 mm 40 mm 0.14 11.2 mm 2.5 µm Transmission Icon 24 95 mm Not Available Not Available M26 x 0.706;
5 mm Depth
MY10X-823 10X 30.5 mm 20 mm 0.26 10.4 mm 1.3 µm Transmission Icon
MY20X-824 20X 20.0 mm 10 mm 0.40 8.0 mm 0.9 µm Transmission Icon
MY50X-825 50X 17.0 mm 4 mm 0.42 3.4 mm 0.8 µm Transmission Icon
  • When Used with a 200 mm Focal Length Tube Lens
  • Entrance pupil diameter (EP) is defined at the back aperture of the objective and calculated as EP=2*NA*EFL.
  • Spot size is calculated at 550 nm, assuming the entrance pupil is filled and the input beam profile is Gaussian.

M = Magnification
WD = Working Distance
EFL = Effective Focal Length
PFL = Parfocal Length

NA = Numerical Aperture
EP = Entrance Pupil Diameter
OFN = Optical Field Number

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
MY5X-822 Support Documentation
MY5X-8225X Mitutoyo Plan Apochromat Objective, 480 - 1800 nm, 0.14 NA, 37.5 mm WD
$1,658.30
Lead Time
MY10X-823 Support Documentation
MY10X-82310X Mitutoyo Plan Apochromat Objective, 480 - 1800 nm, 0.26 NA, 30.5 mm WD
$1,895.20
Lead Time
MY20X-824 Support Documentation
MY20X-82420X Mitutoyo Plan Apochromat Objective, 480 - 1800 nm, 0.40 NA, 20.0 mm WD
$3,409.30
Lead Time
MY50X-825 Support Documentation
MY50X-82550X Mitutoyo Plan Apochromat Objective, 480 - 1800 nm, 0.42 NA, 17.0 mm WD
$4,192.10
Today