In the Emission-Reader Custom chart mode you select the numbers of rows and columns of the chart or target you want to measure; there is no need to open a file of the proper size beforehand. The target height in the Target area definition is required only if you intend to use a previously measured uniformity compensation file for this light box (see Light Box characterization). The target width (i.e. horizontal scan length) is required for patch width validation and if you intend to use a uniformity compensation file; the minimum patch width depends on the i1Pro 3 model, with larger patches required for the i1Pro 3 Plus. Click on the "Start" button once the target area is defined. You can select any patch to make individual measurements, or use a timer to automatically make measurements at fixed time intervals. It is also possible to take measurements one row at a time, by scanning the instrument from one side of the chart to the other. When scanning, the contrast between neighboring patches must be high enough so that the instrument automatically detects a transition OR the patches must be separated by contrast markers consisting of thin black and/or white bars before and after each patch (Note: You can scramble the patches to maximize the contrast or print targets with contrast bars in PatchTool). A Zebra ruler is always required for line scans.

The screenshot above shows the interface after: • defining the Target area; • measuring the White Point (WP) on the white patch (upper-left); • selecting a Scan exposure of 100 ms (instead of the auto-set exposure of 400 ms!); • selecting D50 as the Illuminant and deselecting “Abs.-Col.”, i.e. selecting “Rel.-Col.”; • measuring/scanning the first four rows; • loading the Light Box uniformity compensation file and activating the compensation (”ON” checkbox); • reassigning the white patch as the WP (patch display contextual menu), to take into account the light box non-uniformity. Note: A detailed Custom chart measurement procedure is available in the Help manual. You will note that the Light Box uniformity compensation file (LightBox_160Vx200H- mm_20Rx10C_2.txt) was defined with 20 rows and 10 columns while the target area was defined with 10 rows and 5 columns; the rows and columns do not need to match as long as the area of the compensation file is equal or larger than the target area. Here the compensation file area and the target area are the same size (160Vx200H-mm). When the compensation file area is larger, you can set an offset between the two areas, perhaps to better position the target in a more uniform zone of a light box. Export ABSOLUTE measurements in a RAW file that can be opened in a spreadsheet. Export PROCESSED data , i.e. relative to a selected WP, in a CGATS compatible file which can be opened in most programs that support this format; this file can also be compared to other colors lists within PatchTool. The CGATS file options export dialog is shown below. Screenshots of the "Light Box characterization" mode are shown on the previous page. Screenshots of the "PatchTool file" measurements mode are shown on the next page.