Not enough information to go on. So, have to ask some questions: Does the RA axis track normally if you are not slewing to an object? Can you move the mount in RA via the buttons on the keypad or via

I have just started having a weird problem with this mount. It has worked perfect from day one for several years now. Last night I turned on the mount and initialized it with The SkyX as usual. synced

If you turn the limits off as I suggested, the problem at the meridian flip point should go away. Rolando

Terri, Once a limit is hit the mount will have tracking stopped and the mount will be in a parked state, both unexpected for SGPro and APPM. It could be there was a popup window someplace that needed

You may have to do a centering action in one of the programs (plate solve) to see the issue. I think the software waits for the mount to finish moving to the location, and if it is trying to go to

No frost, no condensation at all. I even have the dew prevention on. I think Roland is spot on with the window theory. The place image at, is on a wooden deck, suspended two stories in the air.

Whenever I have seen a foggy disc or donut like that it has usually been condensation or frost on the inside or the outside of the camera protective front glass above the chip. On the outside on

Yep, green.

Shine a light in there and see what color the reflection is. I'm guessing brilliant green, which means yes it's coated but maybe a bit too thick a coating with high reflectivity in green or

AG Optical 10" iDK. Its a CDK competitor, the only one that sells a 10" model.

Well, that is something I will have a chat with ZWO about. It should be double AR coated on both sides. Thanks for letting me know.🙂

Bill remind me what is that OTA of yours?-- Brian Brian Valente portfolio brianvalentephotography.com

It's a reflection from your camera window that's going back up into the optical path and coming back down to record on the chip. It happens when the sky background is not perfectly dark. Sky light is

Model running tonight, and what do you know... that halo IS there on this system as well. Since its not Astro Dark, I bet it goes away later as I did not see it previously but it was well into Astro

Yeah I took it all apart when I put the DK out. Next time I have the GTX up I will investigate further. It will probably disappear, whatever it was.

Should also show up in your flat field image. Roland

Very little changes needed with the field flattener. I did have this strange halo appear in my frames that I can only reproduce with the flattener. The Quad TCC doesnt show it, and my DK doesnt show

I'm thinking Field Flattener which gives more leeway for any tilt, and has higher resolution. Although resolution is probably not an issue with those tiny pixels. Rolando

There is a heater you can turn on in the ZWO driver to prevent dew.

Nailing down the spacing gets difficult as well, since the tilt is present. Solving the tilt is a challenge when the spacing is not deadly accurate. So you end up in this vicious cycle. I decided to