I am trying to find the filter offsets for my OK3Z focuser by using FocusMax and CCDAP5.
In CCDAP5 there is a wizard that automatically will loop through a given number of series (L - R- G- B - Ha - SII - OIII), focus each filter and noting down the focuser position. One should do at least 5 loops. The offset is then measured with the L-filter as the reference.
For a fast OTA (F3.6) the critical focus zone is only 9microns (CFZ = the zone within which it is not possible to measure a difference in focus). Thus I need to get the offset measurements for the different runs within 9microns.
I now have 20 measurements for each filter.
The problem is that the different measurements differ too much (more than 9microns).
As an example here is the first 9 measurements for the R-filter: 156, 193, 181, 182, 174, 197, 185, 211,184. These are the value to add to the L-filter focus position in order to get the R-filter in focus.
The min value is 156 and the max value is 211. The difference between these are 55 microns which is much more than 9microns (CFZ).
Obviously if I add 156 or 211 to the L-filter position at least one of them will not give correct focus for the R-filter.
I thought the OK3Z focuser was meant to be reliable and able to repeatable.
Anyone else having this issue? Or do you have a repeatable OK3Z focuser? Is there a way to optimize it (adjusting some screws or something)?