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ESATTO 2" focuser reports zero step size causing SharpCap autofocus issues

PrimaLuceLab ESATTO 2" robotic focuser AstroSharp Ltd SharpCap Focuser Auto-Focusing Troubleshooting
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Tom Utendorf avatar
Tom Utendorf avatar

I am using a PrimaLuceLab ESATTO 2" focuser with SharpCap’s Automatic Refocus tool via ASCOM Device Hub. The ASCOM driver (v3.7) reports a step size of 0.0 microns in the static properties. Because of this, I believe SharpCap ignores the step size I enter in the autofocus dialog (1000) and only moves the focuser by one raw step each time.

My setup:

• Telescope: Celestron EdgeHD 9.25 at f/10

• Camera: ZWO ASI2600MC Pro Duo

• Focuser: ESATTO 2"

• ASCOM driver version: 3.7

• ASCOM Device Hub shows: Absolute = True, Max Increment = 439000, Step Size (microns) = 0.0

Expected behavior: The driver should report the correct micron‑per‑step value (I believe it is ~0.04 µm per step for ESATTO 2"), so that SharpCap can multiply the autofocus step size correctly.

Current behavior: SharpCap defaults to “1 step” moves regardless of the autofocus step size entered, making automatic refocus unusable.

Looking for anyone else who's had this problem and solved it or any other recommendations.

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Willem Jan Drijfhout avatar
Willem Jan Drijfhout avatar
Yes, the step-size is 0.04 micron. Is it not possible to fill in step sizes in two decimals?
The software I'm using is always using # steps, not microns. Is there anywhere an option that you can use # steps?
Tom Utendorf avatar
Tom Utendorf avatar

My theory, however flawed it may be, is that SharpCap is multiplying the step count times 0.0 microns that shows in the ASCOM driver and coming up with a maximum of one step no matter how many steps I tell SharpCap to use. I may have found a solution in SharpCap's autofocus tool, but I won't know for sure until I have some stars to test it on. Looks like it's gonna be awhile before that happens. Either way, my concern is that the ASCOM driver reports a step size of 0.0 instead of 0.04 and that that's throwing off SharpCap.

GregsAstrobin avatar
GregsAstrobin avatar

I just tried my Esatto 2 for the first time last night and see this issue. Has anyone found a solution to this?

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