Q1: Which focusers are supported?

The current EAF bracket is compatible with

  • SkyWatcher Astrograph reflectors,
  • SkyWatcher Black Diamond,
  • SkyWatcher Dobsonians,
  • SkyWatcher Maksutov-Newtonians.
  • SharpStar Telescopes
  • SkyRover Telescopes
  • TS Optics
  • Astro Tech
  • Feather Touch
  • Some others such as Explore Scientific will fit with longer screws (not supplied)
  • More focusers will be supported in the future as we develop more brackets


Q2: Does the EAF work with single-speed and/or dual-speed focusers?

If the EAF fits, it does not matter if it is on a single or dual-speed focus knob. We recommend attaching to the coarse focus knob, not the fine focus. There are 4 different sized adapters to attach the EAF to the focus shaft.


Q3: Is the EAF suitable for deep space and planetary imaging?

Yes, the EAF works for all types of astrophotography. With the ASCOM driver, you can use the EAF with any ASCOM compatible software or the ASIAIR.


Q4: Does the EAF make a difference?

Yes, the EAF can make very fine adjustments, meaning it is more accurate than manually adjusting focus. The EAF can also keep you in focus all night when using ASCOM drivers (coming soon to ASIAIR).


Q5: What power supply is required for the EAF?

The EAF requires 12V 0.5A. As long as the power supply is 12V and has 0.5A or more, it will power the EAF. The port is 5.5mm*2.1mm centre positive.


Q6: Can I manually adjust the focus from my Computer?

Yes, the ASCOM driver makes the EAF compatible with capture software that supports electronic focusers.


Q7: Is the focus speed variable?

Yes, the EAF can focus at different speeds. On a computer, you can set the number of steps in a single rotation for precise control.


Q8: Do I need to install drivers to use the EAF

For use with the ASIAIR and ZWO’s computer capture software – ASICAP, no drivers are needed, simply plug and play! For use with other software, the ASCOM driver is required, found here: https://astronomy-imaging-camera.com/software-drivers


Q9: Which capture software supports the EAF?

Sequence Generator Pro, Focus Max, The SkyX, Nebulosity, etc. If the software supports electronic autofocus via ASCOM then the EAF will work.


Q10: How does the EAF attach to a telescope?

First, you need to remove the focus knob from the focuser and check which of the 4 supplied adapters fits your focuser the best. Then attach it to the EAF and the focus shaft, then remove the necessary screws from the bottom of your focuser to then screw the bracket in place.

33 Responses to ZWO EAF FAQ
  1. Avatar

    Hello. I have the skywatcher ED80 DS Pro refractor but with skywatchers own upgraded focuser as per the link below. I need to know if your eaf will fit before ordering please?


    Many thanks


  2. Avatar

    I measured my eaf’s backlash. it was 210 steps.
    but I think it is so huge value. I wonder is it normal value.


  3. Avatar


    I have just upgraded the firmware on my EAF. However the zero position is now with the focusser a third of the way out. Please can you explain how I can recalibrate and let the zero position be fully in. The eaf just beeps at me no matter what I try to do to get the focusser to go in.




  4. Avatar

    Is there a short instruction on how to mount the EAF on a Takahashi Epsilon. Sam mailed me once how to, but it seems I can not find it anymore. I know it was a combination of the Tak kit, and the original bracket, but not sure if I also need the bracket for Takahashi in the picture.



  5. Avatar

    Would the ZWO EAF work with a Meade EXT90 Observer OTA?


  6. Avatar

    Can the ZWO EAF be powered by a leisure battery, i.e. 13.8v?


  7. Avatar

    The EAF (srtandard) doesn’t fit the SW Evostar 72ED, the existing focuser shaft is too long so the shaft from the EAF barely fits into the adapter. Also non of the screws fit into the focuser body (crayford 2″). Is there a solution?


  8. Avatar

    What is the step resolution (in microns) for the EAF?


  9. Avatar

    Can the EAF be installed on a William Optics Zenithstar 61 scope currently, or do I need to wait for a new bracket to be developed?


  10. Avatar

    ZWO EAF also compatible with skywatcher Evostar series Telescope ?


  11. Avatar

    Will I be able to use the focus knob manually? Is there a way of manually decoupling it from the focuser?


    • Avatar

      After you connect EAF to the focuser, it cannot be rotate manually, you need to control it via software or handcontroller.


  12. Avatar

    Will the bracket ever be available for the Esprit 80?


  13. Avatar

    I saw a YouTube video that uses feathertouch mount brackets, but can’t find the part number to order. How do we order those brackets?


  14. Avatar

    Does the EAF supports Moonlite CHL focusers ? If not, is it planned in a next future ?




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