focus_offset

Telescope: LSTS-design

Description: Distance of the starlight focus from the camera pixels (light guides) entry. In telescopes without dynamic focusing capability (either through mirror alignment and camera positioning) this is best set such that starlight gets focused onto the camera lid while showers are focused onto the pixel entry. Zenith angle dependence of the focus offset can be applied and includes the constant value \(\Delta_0\) and terms depending on cosine and sine of the zenith angle. The total focus offset is \(\Delta = \Delta_0 + \Delta_c + \Delta_s\). Set to zero for all 2M telescope types, as it is already included in the first of the par:focal-surface-parameters values, assuming the design value of that is for a light source at a typical shower maximum distance.

Model Version	Value
5.0.0	6.55 cm, 0.0 deg, 0.0, 0.0
6.0.0	6.55 cm, 0.0 deg, 0.0, 0.0