1. If necessary, select the interpolation level in the Interpolation Degree dropdown list in the Focus Surface and Support Points section of the Tiles tool.
  1. You have successfully created a local focus surface. You can now start the experiment. To ensure that the tiles are acquired along the focus surface the software automatically selects the most appropriate focus strategy. For more information on focus strategies read the chapter Working with Focus Strategies.

The minimum number of support points necessary per tile region is indicated in the Interpolation Degree dropdown list for each entry. The calculation is more solid if the number of support points exceeds this minimum number. We therefore recommend that you only increase the interpolation degree as far as the surface of the sample demands, even if you have set more support points. If the number of support points does not correspond to the minimum number for the selected interpolation degree, the interpolation degree will be reduced automatically. By default, ZEN uses a second order interpolation degree that creates a parabolic focus surface and requires at least 9 support points. Typically, this will be suitable for many samples and imaging scenarios.