focus
Differences
This shows you the differences between two versions of the page.
| Next revision | Previous revision | ||
|
focus [2016/11/18 21:56] mike created |
— (current) | ||
|---|---|---|---|
| Line 1: | Line 1: | ||
| - | Focus Sequence | ||
| - | |||
| - | Use Run Focus in the AzCam window to make a focus exposure sequence. | ||
| - | |||
| - | A new instrument command has been added to move the focus actuators to specific LVDT values. | ||
| - | |||
| - | instrument.SetActuators(0.874, | ||
| - | |||
| - | to move the actuators (A,B,C) to the positions indicated. | ||
| - | |||
| - | Misc Focus Info | ||
| - | * The image header has a line like: FOCUSVAL= ' | ||
| - | * These are LVDT (encoder) values corresponding to ' | ||
| - | * One focus actuator step is 2.645 microns, which corresponds to -0.0005 LVDT units. So the conversion is (-1322.5 um/LVDT unit). | ||
| - | * Note the zero point for the LVDT scale is arbitrary and only relative motion should be considered.So for example, 0.756 above for LVDT_A is a position of (0.754 * -1322.5) = -997.2 microns. | ||
| - | * Note the direction sign is reversed between actuator movement and the LVDT readout. | ||
focus.1479531387.txt.gz ยท Last modified: 2016/11/18 21:56 by mike
Except where otherwise noted, content on this wiki is licensed under the following license: CC Attribution-Share Alike 4.0 International
