ACP supports extended filter controls, including focus offset support and selection of separate filters for use during auto-focus and pointing updates. These optional settings for filter usage are contained in a configuration file. ACP comes with a pre-written script which will determine the focus offsets for your filters automatically. All you do is tell it which filter you want to use as the focus reference (0-offset) filter. ACP then chooses this filter for Auto-Focus operations regardless of which filter happens to be selected for imaging at that time.

Filters can be organized into offset groups as well. A typical usage would group astro-imaging filters (Clear, Red, Blue, Green) into one group and photometric filters (U, B, V, R, I) into another group. Each group can have its own focus reference filter. Each group can also have its own filter to be used for Every Image Centered™ pointing updates (normally the one that transmits the most light).

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