Can Outlier rejection parameters be set to exclude subs with streaked stars?

Hi Rudy,

There are several ways in which you can handle this.

After registration, you will see information in the FWHM min, max column in the bottom frame list panel. The frames that have elongated stars will have big differences between then minimum and maximum value. Also, the quality score will be much lower than the other frames. Based on that information, you can

1. manually deselect these frames (in 1) load you can then remove the deselected frames with the clean button to the right of the load lights button), they won't be included in the integration then
2. in 6), use the lights to stack slider , to exclude the frames with the lowest quality scores, these will be the frames with the elongated stars.
3. or you can just include them in the integration and try to use star shape weights in 6) integrate. This will have the effect that the frames with the elongated stars will still contribute to lowering the noise in the sky background, while maintaining round stars in the integration. So frames with elongated stars will have a much lower weight than frames with round stars. If you have a couple of frames with elongated stars, then this will work very well 😉 and is preferred over option 1) and 2), because the Signal to Noise Ration with method 3) will be better.

Using outlier rejection can be helpfull to shave off the elongated star shapes as well, but only use it as a last option, because if you set the outlier rejection too strong, the noise in the integration will be higher. Using star shape weights, in most cases, is by far the best option if your stack contains frames with elongated stars 😉

Kind regards,

Mabula

Thanks Mabula,

This looks great, I will give each of these solutions a try.

Have a great day!
Rudy