Auto Focus Problem with Some Objects

Sequence Generator Auto Focus
1

On many objects I get very good Auto Focus results. For example here is an AF curve from the other night while imaging NGC 2903:

However, on some objects; particularly globular clusters or bright galaxies the AF process exhibits significantly distorted curves and fails to obtain a good focus. Here is an example from the same night while imaging M51:

Are there setting in the AF panel that I should adjust for different objects?

I have attached a link to the SGP Log file in my Dropbox: SGP Log File

Thanks,

Fred

2

@fjkeller

Unfortunately there are too many environmental variables in play for logs to be of any real use when troubleshooting AF. If you are able to capture an AFPack of the problem runs, we can take a look at that.

3

Hi Ken,

Here is a Dropbox link to the AFPack: AFPack91

Thanks for taking the time to look into this.

Fred

4

I ran into this problem last night too and tried a range of min star diameters. I ended up manually slewing away from the globular to focus, then re-center. I’ll see if I have an AFPack from the run.