Thorlabs offers a variety of options for measuring the distortion of an optical system including targets with a single-frequency grid, multi-frequency grids, or distortion grids alongside a wide variety of other patterns for resolution measurement, calibration, and more. Combined, these targets offer grid spacings ranging from 5 µm to 5000 µm.
- Test Targets Help Identify Distortion in Imaging Systems
- Grid Spacings Available from 5 µm to 5000 µm
- Combined Resolution and Distortion Targets Available
A variety of targets are offered, including positive and negative fixed-frequency grid distortion targets, multi-frequency grid distortion targets, single-frequency rochi ruling targets, concentric circle and crosshair grid targets, and combined resolution and distortion targets. We also offer a positive reflective version of the multi-frequency target and a negative version of the 18 mm x 18 mm combined resolution and distortion target. The targets below are made by plating vacuum-sputtered low-reflectivity chrome on a soda lime glass substrate in patterns of either horizontal and vertical lines or rows and columns of solid circles. See the Graphs tab for spectral data of the materials used in these distortion targets.
Each pattern is manufactured using photolithography, allowing for edge features to be resolved down to approximately 1 µm. Since the targets have parallel lines or perpendicular rows and columns, they will be imaged as such by an ideal system. A distorted image will show the lines or rows and columns as bowed; this image allows the user to quantify the distortion and thus to correct for it using software built into programs such as LabVIEW or ImageJ.
- One Grid Array on a 1.50" x 1.50" (38.1 mm x 38.1 mm) Soda Lime Glass Substrate
- 50 µm, 125 µm, 250 µm, 500 µm, or 1000 µm Grid Spacings
- Ø25 µm, Ø62.5 µm, Ø125 µm, Ø250 µm, or Ø500 µm Dots
Ideal for Stage Calibration and Distortion Detection in Machine Vision Applications
These distortion grid arrays each feature a single grid of dots fabricated from the deposition of vacuum-sputtered, low-reflectivity chrome on a soda lime glass substrate. The available grid spacings, which are measured from the center of any dot to the center of any adjacent dot, range from 50 µm to 1000 µm, and the dot diameters range from 25 µm to 500 µm.
Grid arrays are used to determine the distortion of an imaging system. Ideally, the horizontal and vertical rows of dots should be perpendicular to each other. A distorted image will show the array as bowed; this image can then be used to correct for distortion.
Features
- Fixed and Multi-Frequency Grid Distortion Test Targets
- High-Contrast Positive Reflective Target Available
- Combined Resolution and Distortion Test Targets
- Distortion in Grid Image Allows for Image Correction
- Grids Available with Spacings of 5 µm to 5000 µm
Above: An R2L2S3P3 Target Post Mounted via an FFM1 Filter Mount and a B3C Cube Base for Use in a Custom Imaging System