Strange artifacts from Integration

[Astrocava]

Hi all!

I have strange artifacts integrating the intermediate files calibrated from DSS  Is the first time I get this. Below a comparison between DSS (left) and PI (right). They are like tails. Look to the artifact just near the bright star pointed by the cone. Strange.

Sergio

[Carlos Milovic]

Try decreasing the upper sigma value for the rejection algorithm.

[Philip de Louraille]

Interesting. The resulting stars in PI look a bit smaller than with DSS. But, if I look carefully at the DSS image, I can convince myself that I see the artifacts there too. I think that PI gets a better job to tell you that the alignments of your setup (telescope primary light capturing device to CCD is not aligned perfectly.)

[Astrocava]

Try decreasing the upper sigma value for the rejection algorithm.

Thanks for the tip, but doesn't work. :-(

Interesting. The resulting stars in PI look a bit smaller than with DSS. But, if I look carefully at the DSS image, I can convince myself that I see the artifacts there too. I think that PI gets a better job to tell you that the alignments of your setup (telescope primary light capturing device to CCD is not aligned perfectly.)

I don't see them. Check the strange artifact just under the biggest star right of the cone. Is clearly not in DSS.

Stars smaller with PI can be because the different STF applied.

[Silvercup]

Sergio:

Try median combine with no normalization.

Silvercup

[Juan Conejero]

Hi Sergio,

I have strange artifacts integrating the intermediate files calibrated from DSS

I can't say anything definitive without looking at the images. Also, we'd need more information about the integration procedures. What integration algorithms and what parameters did you use with PI and DSS?

[Andres.Pozo]

Stars smaller with PI can be because the different STF applied.

Some time ago I made some tests comparing the registration/stacking between DSS and PI and with PI you do get smaller stars. The effect was not huge but it was noticeable.

[Astrocava]

Hi Sergio,
I can't say anything definitive without looking at the images. Also, we'd need more information about the integration procedures. What integration algorithms and what parameters did you use with PI and DSS?

This is another image that shows the artifacts a bit better.

Juan, Which type of images do you want to see? Final results or subs? Parameters of integration in attached image.

[Alejandro Tombolini]

Could it be an unregistered image? Why don't you check your registered images with Animation.?

[Philip de Louraille]

Ah... I see the artifacts you are mentioning now, I thought you were referring to the stars themselves (there is a small "tail" on the bright ones.) The stars are quite bright. Do these artifacts also occur if you choose "additive & scaling" for the Image Integration?