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Microscope Image of R1DS1N Negative Test Target

• Ø1" (Ø25.4 mm) Targets for Alignment in Ø1" Lens Tubes
• Determine Resolution of an Optical System
• Conforms to MIL-S-150A Standard
• Positive and Negative Targets Available
• Sets of Three Lines Minimize Spurious Resolution

Thorlabs offers positive and negative Ø1" (Ø25.4 mm) resolution test targets that are made by plating vacuum-sputtered chrome on a soda lime glass substrate. These targets have 6 groups (+2 to +7) with 6 elements, offering a maximum resolution of 228.0 line pairs (one light line and one dark line) per millimeter. For more information on the 1951 USAF pattern, please see the Resolution Targets tab above.

Because these targets feature sets of three lines, they reduce the occurrence of spurious resolution and thus help prevent inaccurate resolution measurements. For more information on spurious resolution, please see the Resolution Targets tab.

The R1DS1P positive target consists of a chrome pattern with low reflectance plated on to a clear substrate and is useful for front-lit and general applications. Alternatively, the R1DS1N negative target uses the same chrome coating to cover the substrate, leaving the pattern itself clear, and works well in back-lit and highly illuminated applications.

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Microscope Image of R3L1S4N Negative Test Target

• 3" x 1" (76.2 mm x 25.4 mm) Targets for Measuring Resolution Across Image
• Determine the Resolution of an Optical System
• Conforms to MIL-S-150A Standard
• Positive, Negative, and Positive Reflective Targets Available
• Compatible with our MLS203 Microscope Stages via MLS203P2 Slide Holder

Thorlabs offers positive and negative 3" x 1" (76.2 mm x 25.4 mm) resolution test targets that are made by plating vacuum-sputtered chrome on a soda lime glass substrate. The 3" x 1" wheel pattern targets have nine 1951 USAF targets, each with 6 groups (+2 to +7), offering a maximum resolution of 228.0 line pairs (one light line and one dark line) per millimeter. For more information on the 1951 USAF pattern, please see the Resolution Targets tab above.

Because these targets feature sets of three lines, they reduce the occurrence of spurious resolution and thus help prevent inaccurate resolution measurements. For more information on spurious resolution, please see the Resolution Targets tab.

Thorlabs offers the R3L1S4P positive target composed of a chrome pattern etched on soda lime glass, useful for front-lit and general applications, with a clear soda lime substrate background for for front-lit and general applications. Alternatively, the R3L1S4N negative target uses the chrome to cover the substrate, leaving the pattern itself clear, and works well in back-lit and highly illuminated applications. The R3L1S4PR positive reflective target is composed of a dark AR-coated chrome pattern on an uncoated chrome background; the high contrast between the pattern and the background makes this target ideal for reflective applications. See the Graphs tab for details.

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Microscope Image of R3L3S1N Negative Test Target

• 3" x 3" (76.2 mm x 76.2 mm) Targets Offer Resolution up to 4.4 µm per Line Pair
• Determine Resolution of an Optical System
• Conforms to MIL-S-150A Standard
• Positive, Negative, and Positive Reflective Targets Available

Thorlabs offers positive and negative 3" x 3" (76.2 mm x 76.2 mm) resolution test targets that are made by plating chrome on a soda lime glass substrate. The 3" x 3" targets have 10 groups (-2 to +7) with 6 elements per group, offering a maximum resolution of 228.0 line pairs (one light line and one dark line) per millimeter. For more information on the 1951 USAF pattern, please see the Resolution Targets tab above.

Because these targets feature sets of three lines, they reduce the occurrence of spurious resolution and thus help prevent inaccurate resolution measurements. For more information on spurious resolution, please see the Resolution Targets tab.

Thorlabs offers the R3L3S1P positive target composed of a chrome pattern etched on soda lime glass, useful for front-lit and general applications, with a clear soda lime substrate background for for front-lit and general applications. Alternatively, the R3L3S1N negative target uses the chrome to cover the substrate, leaving the pattern itself clear, and works well in back-lit and highly illuminated applications. The R3L3S1PR positive reflective target is composed of a dark AR-coated chrome pattern on an uncoated chrome background; the high contrast between the pattern and the background makes this target ideal for reflective applications. See the Graphs tab for details.

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Close Up of the R1L3S10P NBS 1952 Target

• 3" x 1" (76.2 mm x 25.4 mm) Target for Measuring Resolution with One-Pass Scanning
• NBS 1952 Target with Centered Crosshair
• Resolutions from 2.4 to 80 lp/mm
• Sets of Three Lines Minimize Spurious Resolution

Thorlabs' 3" x 1" (76.2 mm x 25.4 mm) NBS 1952 Resolution Target offers 48 sets of lines with 24 different frequencies ranging from 2.4 to 80 line pairs (one light line and one dark line) per millimeter (lp/mm), as listed in the table below. In the center of the NBS 1952 target is a crosshair with a length and width of 610 µm and two concentric circles with diameters of 250 µm and 500 µm. Because the line sets on this target are arranged such that every resolution can be viewed by traveling in only one direction (either horizontally or vertically) along the pattern, the resolution of an optical system can be determined with one pass. For more information about the NBS 1952 pattern, please see the Resolution Targets tab above.

Because this target features sets of three lines, it reduces the occurrence of spurious resolution and thus helps prevent inaccurate resolution measurements. For more information on spurious resolution, please see the Resolution Targets tab.

The pattern on this target is made from plating low-reflectivity, vacuum-sputtered chrome on a 0.06" (1.5 mm) thick soda lime glass substrate to achieve an optical density of ≥3.0 at 430 nm. The dark pattern and clear substrate are useful for front-lit and general applications.

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Close Up of the R3L3S6P NBS 1952 Target

• 3" x 3" (76.2 mm x 76.2 mm) Target for Measuring Resolution with One-Pass Scanning
• NBS 1952 Target with Centered Crosshair
• Resolutions from 0.48 to 16 lp/mm
• Sets of Three Lines Minimize Spurious Resolution

Thorlabs' 3" x 3" (76.2 mm x 76.2 mm) NBS 1952 Resolution Target offers 48 sets of lines with 24 different frequencies ranging from 0.48 to 16 line pairs (one light line and one dark line) per millimeter (lp/mm), as listed in the table below. In the center of the NBS 1952 target is a crosshair with a length and width of 3100 µm and two concentric circles with diameters of 1250 µm and 2500 µm. Because the line sets on this target are arranged such that every resolution can be viewed by traveling in only one direction (either horizontally or vertically) along the pattern, the resolution of an optical system can be determined with one pass. For more information about the NBS 1952 pattern, please see the Resolution Targets tab above.

Because this target features sets of three lines, it reduces the occurrence of spurious resolution and thus helps prevent inaccurate resolution measurements. For more information on spurious resolution, please see the Resolution Targets tab.

The pattern on this target is made from plating low-reflectivity, vacuum-sputtered chrome on a 0.06" (1.5 mm) thick soda lime glass substrate to achieve an optical density of ≥3.0 at 430 nm. The dark pattern and clear substrate are useful for front-lit and general applications.

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Microscope Image of R2L2S1N Negative Test Target

• Frequencies from 1 to 18 cycles/mm (See List to the Right)
• Determine Resolution of an Optical System
• 2" x 2" (50.8 mm x 50.8 mm) Soda Lime Glass Substrate
• Positive and Negative Targets Available

Thorlabs' 2" x 2" (50.8 mm x 50.8 mm) NBS 1963A resolution test targets offer 26 line sets with frequencies from 1 to 18 cycles/mm, corresponding to cycle sizes from 1.0 mm to 55.6 µm (see the table to the right and the Resolution Targets tab for more information). Each set of lines on the pattern contains five horizontal and five vertical lines and is labeled with the frequency of the lines in cycles/mm, as shown in the images to the right. The resolution of an optical system can be determined by identifying the highest frequency line set that the system is able to resolve.

These resolution targets are offered in positive and negative versions. The R2L2S1P positive target consists of a chrome pattern with low reflectance plated on to a clear substrate and is useful for front-lit and general applications. Alternatively, the R2L2S1N negative target uses the same chrome coating to cover the substrate, leaving the pattern itself clear, and works well in back-lit and highly illuminated applications.

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Line sets with frequencies of 32 and 29 cycles/mm on the R2L2S1N1 negative target. The enlarged image shows line sets of 7.1 through 228 cycles/mm.

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Line sets with frequencies of 32 and 29 cycles/mm on the R2L2S1P1 positive target. The enlarged image shows line sets of 7.1 through 228 cycles/mm.

• Frequencies from 1 to 228 cycles/mm (See List Below)
• Determine Resolution of an Optical System
• 2" x 2" (50.8 mm x 50.8 mm) Soda Lime Glass Substrate
• Positive and Negative Targets Available

Thorlabs' 2" x 2" (50.8 mm x 50.8 mm) high-frequency NBS 1963A resolution test targets offer 48 line sets with frequencies from 1 to 228 cycles/mm, corresponding to cycle sizes from 1.0 mm to 4.4 µm (see the table below and the Resolution Targets tab for more information). Each set of lines on the pattern contains five horizontal and five vertical lines and is labeled with the frequency of the lines in cycles/mm, as shown in the images to the right. The resolution of an optical system can be determined by identifying the highest frequency line set that the system is able to resolve.

These resolution targets are offered in positive and negative versions. The R2L2S1P1 positive target consists of a chrome pattern with low reflectance plated on to a clear substrate and is useful for front-lit and general applications. Alternatively, the R2L2S1N1 negative target uses the same chrome coating to cover the substrate, leaving the pattern itself clear, and works well in back-lit and highly illuminated applications.

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This image depicts the pattern placement relative to the inscribed rectangles on the front of the test target.

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Image of R2L2S1B as seen through two crossed wire grid polarizers. The enlarged image shows the positive pattern on the left and negative pattern on the right.

• Determine Resolution of a Polarizing Optical System
• Birefringent Target Displays Both Positive and Negative Patterns
• Frequencies from 1 to 18 cycles/mm (See List Below)
• 2" × 2" (50.8 mm × 50.8 mm) N-BK7 Glass Substrate

Thorlabs offers a birefringent 2" x 2" (50.8 mm x 50.8 mm) NBS 1963A resolution test target that is made by sandwiching a birefringent pattern between two N-BK7 glass substrates. The test pattern is only observable if the target is placed between a pair of crossed polarizers (see image to the right).

The target is designed so that it can display both positive and negative patterns by adjusting the orientation of the crossed polarizers relative to the test target. If the cross polarizers are aligned with the sides of the glass covers, the positive image will be formed. If the cross polarizers are aligned at 45° to the sides of the glass covers, the negative image will be formed. Because of its polarization sensitivity, this resolution target is ideal for calibrating and testing the resolution of polarizing microscopes, microscopes with a Nomarski mode, polarization imaging systems, or Mueller Matrix polarimeters.

This target has 26 sets of five horizontal and five vertical lines. Each set of lines is labeled with a number, which refers to the number of cycles per mm. With a maximum frequency of 18 cycles/mm, the smallest cycles are only 0.0556 mm. For more information, please see the Resolution Targets tab above. Since the pattern is only visible through crossed polarizers, the target is inscribed with two rectangles for reference. The image on the far right shows the pattern placement with respect to these inscribed rectangles.

See the Resolution Targets tab above for more details on the test patterns.

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Close Up of the R1L1S3P Sector Star Pattern

• 1" x 1" (25.4 mm x 25.4 mm) Positive Sector Star Targets
• Determine Resolution of an Optical System
• Low-Reflectance, Vacuum-Sputtered Chrome on Soda Lime Glass

Thorlabs offers two 1" (25.4 mm) square targets with positive Sector star (also known as Siemens star) patterns. The R1L1S2P target has 36 bars over 360°. The resolution at the center circle of this target is 57.5 lp/mm. Alternatively, the R1L1S3P target has 72 bars over 360°, and the resolution at the center is 115 lp/mm. Both targets also have a Ø200 µm center circle and are useful for determining the resolution of an optical system by noting how close to the center of the pattern an optical system is able to resolve adjacent bars. For more information about sector star patterns, please see the Resolution Targets tab.

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Close Up of R1L3S14N Ronchi Ruling Pattern

• 3" x 1" (76.2 mm x 25.4 mm) Square Wave Ronchi Ruling Target
• Patterns with 10 lp/mm, 20 lp/mm, 40 lp/mm, and 80 lp/mm
• Large 65 mm x 17 mm Clear Aperture
• Determine Resolution, Field Distortion, and Parfocal Stability in an Optical System
• AR-Coated, Vacuum-Sputtered Chrome on Soda Lime Glass
• Compatible with our MLS203 Microscope Stages via MLS203P2 Slide Holder

Thorlabs offers four versions of Ronchi ruling targets with resolutions ranging from 10 line pairs (one light line and one dark line) per millimeter (lp/mm) to 80 lp/mm. These square wave, constant-interval bar and space patterns are fabricated from the deposition of a dark AR-coated chrome pattern on a 3.00" x 1.00" x 0.06" (76.2 mm x 25.4 mm x 1.5 mm) soda lime glass substrate. This leaves a large 65 mm x 17 mm clear aperture, and works well in back-lit and highly illuminated applications. The dimensions of the glass substrate are the same as a standard microscope slide. These Ronchi rulings are excellent for evaluating resolution, field distortion, and parfocal stability in optical systems. For more information about the Ronchi rulings, please see the Resolution Targets tab above.

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Close Up of R1L3S6P Variable Line Grating Pattern

• 3" x 1" (76.2 mm x 25.4 mm) Variable Line Grating Target
• Resolutions from 1.25 lp/mm to 250 lp/mm
• Determine Resolution of an Optical System
• Vacuum-Sputtered Chrome on Soda Lime Glass
• Compatible with our MLS203 Microscope Stages via MLS203P2 Slide Holder
• High-Contrast Positive Reflective Target Available

Thorlabs offers two 3" x 1" positive variable line gratings with 18 sections of line grating with resolutions ranging from 1.25 line pairs (one light line and one dark line) per millimeter (lp/mm) to 250 lp/mm. The table below lists of each available resolution. The resolution of an optical system can be measured by determining the highest resolution grating with lines that the system is able to resolve.

Thorlabs offers the R1L3S6P positive target composed of a chrome pattern etched on clear soda lime glass, useful for front-lit and general applications. The R1L3S6PR positive reflective target is composed of a dark AR-coated chrome pattern on an uncoated chrome background; the high contrast between the pattern and the background makes this target ideal for reflective applications. See the Graphs tab for details.

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Close Up of the Smaller Grid on the R3L3S5P Target with Labels Added (See Tables Below)

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Close Up of Entire Pattern on the R3L3S5P Target

• Concentric Circles and Crosshair Patterns Arranged in a Grid
• Four Different Concentric Circle Sizes and Five Different Crosshair Sizes
• Measure Resolution, Distortion, and Magnification of an Imaging System
• 3" x 3" (76.2 mm x 76.2 mm) Soda Lime Glass Substrate

Thorlabs' 3" x 3" (76.2 mm x 76.2 mm) Concentric Circle and Crosshair Grid Target offers 289 individual grids, arranged in a larger, 2" x 2" grid of 17 rows and 17 columns. The smaller grids each have four concentric circle patterns and five crosshair patterns of varying sizes. The concentric circle and crosshair patterns on the smaller grids are labeled in the image to the right but not on the target itself. Each concentric circle pattern features seven different radii, while the crosshairs each have a single or a double cross. For details on the dimensions of these patterns, see the tables below.

The pattern on this target is made from plating low-reflectivity, vacuum-sputtered chrome on a 0.06" (1.5 mm) thick soda lime glass substrate to achieve an optical density of ≥3 at 430 nm. The dark pattern and clear substrate are useful for front-lit and general applications.

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Microscope Image of the R1S1L1N Negative Test Target

• Measure Image Distortion, Astigmatism, and Other Aberrations
• 18 mm (0.71") Square, 1.5 mm Thick Target
• Determine Resolution of an Optical System
• Includes 1951 USAF Pattern, Sector Star, Concentric Circles, Grids, and Ronchi Rulings
• Positive and Negative Targets Available

Thorlabs offers positive and negative 18 mm x 18 mm x 1.5 mm combined resolution / distortion test targets that are made by low-reflectivity, vacuum-sputtered chrome with an optical density of ≥3 at 430 nm on a soda lime glass substrate. They are ideal for calibration of imaging systems and microscope stages.

The test targets include a 1951 USAF pattern (Groups 2 - 7), a sector star, concentric circles, grids (100 µm, 50 µm, and 10 µm), and Ronchi rulings (30 - 150 lp/mm). These targets are useful for testing resolution, field distortion, focus errors, and astigmatism. The 1951 USAF targets are useful for measuring imaging resolution. For more information, please see the Resolution Targets tab above. The grids can be used to measure image distortion, while the concentric circles are ideal for identifying focus errors, astigmatism, and other aberrations existing in an imaging system. The Ronchi rulings are excellent for evaluating resolution, field distortion, and parfocal stability.

These resolution targets are offered in positive and negative versions. The R1L1S1P positive target consists of a chrome pattern with low reflectance plated on to a clear substrate and is useful for front-lit and general applications. Alternatively, the R1L1S1N negative target uses the same chrome coating to cover the substrate, leaving the pattern itself clear, and works well in back-lit and highly illuminated applications.

• Line Pairs per Millimeter

• 3" x 1" (76.2 mm x 25.4 mm) Target
• Includes NBS 1963A Pattern, Sector Star, Concentric Circles, Grids, Ronchi Rulings, and More (See Table Below)
• Determine Resolution of an Optical System
• Measure Image Distortion, Astigmatism, and Other Aberrations
• Compatible with our MLS203 Microscope Stages via MLS203P2 Slide Holder

Thorlabs offers positive 3" x 1" x 0.06" (76.2 mm x 25.4 mm x 1.5 mm) combined resolution / distortion test targets that are made by low-reflectivity, vacuum-sputtered chrome with an optical density of ≥3 at 430 nm on a soda lime glass substrate. They are ideal for calibration of imaging systems and microscope stages. They are sized to fit in our MLS203P2 stage slide holder for use with our MLS203 microscope stages.

The test targets include an NBS 1963A pattern, a sector (Siemens) star, concentric circles, grids, Ronchi rulings, and more (see table below). These targets are useful for testing resolution, field distortion, focus errors, and astigmatism. The NBS 1963A, sector star, and concentric circle targets are useful for measuring imaging resolution. For more information, please see the Resolution Targets tab above. The grids can be used to measure the distortion introduced by an imaging system. The Ronchi rulings are excellent for evaluating resolution, field distortion, and parfocal stability.

• The unit lp/mm is line pairs per millimeter.