ASIAIR based workflow

Focusing using the ASIAIR Focus Mode

updated: 2025-09-01

Purpose

Who to get to optimal focus for best images:

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Good focusing is a prerequisite for using the GoTo or Plate Solve features. Both require well-focused equipment. These instructions apply to both the main camera and the guide camera. To use this procedure for the guide camera, the guide camera must first be registered as the main camera on the ASIAR (this is not possible with combined main/guide cameras such as the ASIAIR 2600 MC AIR).

Important steps ahead of focusing: 


  1. 1. Open Focus Mode from the menu on the right side of the ASIAIR.:
  2. In Focus Mode et the exposure time to 1-3 seconds.
  3. Loosen the locking screw on the focuser so it can be moved freely.
  4. Reset the focuser: 
    1. No EAF: no reset required
    2. With EAF: Use the Goto 0 function in the Focuser Setting Panel to move your focuser to the 0 position. If another value is displayed, update the Current Position to 0. 
  5. Focus Preset: 
    1. If using a standard configuration, such as the TS600AS294, move the focuser to the optimal focus position previously measured.
      1. No EAF:  manually adjust the focuser to the previously measured focus distance.
      2. With EAF: 2. Use the GoTo function in the Focuser Setting Panel. Enter the known focus value for this configuration, then click GO.
    2. For an unknown optical configuration, use the ASIAIR video mode for initial rough focusing.

  6. Find a bright star. Manually slew your telescope to some brighter stars, or leave the mount in the home position and use the stars near Polaris to focus.
  7. Tap the round record button in the ASIAIR app.
  8. The ASIAIR then continuously takes photos of the starry sky with this exposure time and displays them one after the other. A small square with a plus sign in the middle appears on the current image.
  9. Drag the plus sign in the green square onto a clearly visible star.
  10. Then click on the zoom tool (at the top) in the left-hand bar and the selected section will be displayed greatly enlarged.

    (simulated picture)
  11. In addition, the star size (HFR - Half Flux Radius) and the peak value are displayed. The HFR value should be as small as possible and the peak value as large as possible. The focuser must be moved in both directions accordingly in order to achieve the optimum values (maximum image sharpness).

Tables: Optimal Focuser Start Settings for Different Optical Configurations and ASI EAF

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