Best practices for using transmissive test targets

Light Source

 

The most uniform light source available would be an integrating sphere, but these come with considerable size and expense. After considering how the light source uniformity impacts their results, most lab & manufacturing tests use LED or fluorescent lightboxes with flat-panel diffusers. Some customers choose a larger lightbox because that leads to greater uniformity within the central image plane area. We have performed a study of lightbox uniformity to see how different models compare. 

To perform tests with a transmissive chart setup, devices with built-in light sources will need to have that light source disabled. (more…)

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Mounting Reflective Targets with Spray Adhesive

Step 1: Gather your materials

  • Chart or Print
  • Foam Board (AKA Gator Board) found at a local art supply store or an online retailer such as Foamboardsource.com.
  • Spray Adhesive such as 3M 77 or Photomount
  • Clean towel or cloth
  • paper towels, or a second towel/cloth
  • A friend or colleague. It will be very helpful to have a second set of hands to help with mounting larger targets.

Step 2: Prepare the work area

  • Find a clean work surface large enough to accommodate the foam board and the chart.
  • Wipe down your work surface with a paper towel and ensure it is fully dry before proceeding.

Step 3: Spray the chart and foam board

  • Follow the instructions on your spray adhesive:
  • Apply a generous, even coating of spray to the chart
  • Apply a generous, even coating of spray to the board

Step 4: Bond the Surfaces *

  • Carefully lift and turn the chart over, holding it above the foam board by the corners of one of the shorter sides.
  • Slowly lower one of the short ends of the chart and align two corners of the chart with two corners of the board.
  • Use a clean towel to push the chart on to the board gently but firmly, lowering the chart as you press down.
  • Progressively smooth the chart on to the board in order to ensure that there are no air bubbles.

* It will be best to use two people to do this:

 

  • one person to lift the chart upright, and slowly lower the chart down.
  • one person to align the bottom corners of chart, then use the clean towel to smooth down the chart as the first person lowers it.

 

 

See also

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