OPTIC Autofocus Routines (other than Video Mode)

There are two OPTIC scripts scripts available for focusing the telescope. They are:

1. call focus (E)
2. call autofoc (E, F)

Each script is used by typing the line:

> call <routine name>

in the otcom window.

Focus Routine 1 - not automated

call focus (E)

where E = 5 seconds by default or, the user can enter a number for the exposure time

This routine gives 6 focus steps in the focus frame, and prompts the user to ask the OA to set the starting focus value, and at each step offset the telescope and change the focus value.

Focus Routine 2 - automated

call autofoc (E, F)

where E is the integration time and F is the relative focus offset step.

E defaults to 5 seconds and F defaults to +20 units. + and - steps are allowed but F cannot be larger than +/-300. Typical step sizes to use are 50 and 20 units for rough and fine focus control.

This routine prompts the user to ask the OA to set the starting focus value. It was designed this way to make sure the user actually talks to the OA so all know a focus routine is happening. Once set the routine will move the telescope and change the focus by itself and produce 5 focus steps in the focus frame.

Note: The time reported per step will be 2 seconds less than the actual requested time, but this is just a “feature” of the OPTIC/WIYN shutter interaction - all is really correct in the integration time.

Autofoc steps 10” east per step with a double step before the last focus value. It then resets the telescope back to the starting position before it ends.