Addendum - Tables

Focus Table iOptron Focuser

updated: 2021-07-31

The iOptron Electric Focuser can only report relative and no absolute positions. It is therefore important to initialize the focuser from a stable and well-defined position, that can easily be adjusted before starting to move the focuser electrically.

IMPORTANT: Before connecting the focuser, you should:

  • move the eyepiece to the outermost position (see below)
  • and only then connect the cable between the focuser and the main controller of the iEQ45 mount
  • the focuser will then report the values in the MAX column below:

Focus Table for Min and Max values for iOptron Electric Focuser


(innermost position)

(initial, out-most position)

Manual eye piece extension



iOptron Commander (Focuser Panel)



SGPro (Focus tab in the Control Panel)



Focus Table for Initial Focus Position

To start auto focusing using SGPro, use the initial focus positions from the table below, they are near the best focus position and can used by the SGPrp algorithm to find the best focus.


  Initial focus position 
(should be set ~60 steps lower than the expected optimal focus as the autofocus process will first attempt to step outwards)

Manual eye piece extension

iOptron Commander (Focuser Panel)

SGPro (Focus tab in the Control Panel)

TSOptics 90/600 APO, no Reducer



99735 ... 99670

TSO 90/600 - ZWO-ASI294 + Riccardi Reducer configuration




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