ASIAIR Fails to plate solve after meridian flip in narrowband

brianboyle

For the last two nights, ASIAIR has failed to plate solve successfully after a meridian flip. The logs just show repeated attempts to plate solve with 500+ stars. In one case it finally plate solved after one hour, in the other case it never plate solved. I have never had an issue like this before and I have been using the ASIAIR for 4 years. The only thing I can think of it is narrowband [the first time it was [OIII] and the second Ha]. The target was the Eta Carina nebula - so plenty of stars. And the telescope was in focus. Has anyone experienced a similar issue.
Thanks
Brian

PMTeam@ZWO

brianboyle Hi. Are you using EFW? Have you set it to refocus after switching filters? Also, what is the exposure time for the two filters? The plate solve failure may be related to these reasons.

Astrop

What focal length and camera?

500 stars sounds a lot for an o3 filter, also when it flipped are you positive the new orientation didn't have intrusive light sources shining down the OTA or sky glow in the FOV of the scope?

When you change to narrowband you normally have to increase the centre exposure time in order for plate solving to work more reliably, especially with o3.

wvreeven

I, too, think that 500 stars is too much. Probably noise instead of real stars. What exposure time do you use for centering? Try increasing it as Astrop suggested.

brianboyle

Many thanks. I was using 2secs exposure at 2000mm focal length with binx2 in Bortle 2. I have since increased it to 10sec and no further problems.