Two different defects in two stacked linear images

Registration Artifacts Troubleshooting
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Jerry Gerber avatar
Jerry Gerber avatar

Two defects have suddenly shown up in these linear, stacked images. The first is a luminance stacked linear image. The individual sub-frames show no such defect so it’s happening after using WBPP to calibrate and stack the images. I am running WBPP at its slowest option to keep image quality as high as possible. You can see the streaks spread across the image, clearly not satellites, jets or meteor streaks, which Pixinsight does a very good job of removing.

The 2nd defect, a blue filter linear stacked image is caused by, I think, the following, but I could be wrong. When imaging the other night I noticed that M51, which should have been exactly in the middle of the frame, had moved to the left, probably after the meridian flip. When registering these images, WBPP got the registration correct but since it had to move numerous subframes to match the galaxy and the star’s location in the image, it cut off the right side of the image. I don’t know why the 10Micron GM1000 mount did not complete the plate solving and sync properly if that is in fact what is causing this.

Anyone know what might be going on in either image?

Thanks,

📷 masterLight_BIN-1_6248x4176_EXPOSURE-180.00s_FILTER-Luminance_mono.jpgmasterLight_BIN-1_6248x4176_EXPOSURE-180.00s_FILTER-Luminance_mono.jpg

📷 M51 Blue Linear with right edge defect.jpgM51 Blue Linear with right edge defect.jpg

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HR_Maurer avatar
HR_Maurer avatar

First image - did you check all of your subs? How many subs did you integrate?

Second image - there was a guiding drift during capturing, and your registering reference is offset to most of the integrated images.

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Tony Gondola avatar
Tony Gondola avatar

The first image sure looks like a passage of an aircraft through one of your subs that wasn’t entierly removed by WBPP. Since it’s not showing on any of your lights, I wonder if it’s in one of your flat frames?

Francesco Meschia avatar
Francesco Meschia avatar

Definitely a jet in the first image. I would re-check the individual subs.

Jerry Gerber avatar
Jerry Gerber avatar

Thank you all for responding. I found the culprit, it was an airplane. I usually use Blink to check all of my subframes, but this time I didn’t. It turns out one luminance sub had a very pronounced jet trail, so pronounced that Pixinsight couldn’t get all of it. Here it is:

📷 LIGHT_M 51_Luminance_180.00_-10.00_2026-05-07_00-19-17_0017_1.jpgLIGHT_M 51_Luminance_180.00_-10.00_2026-05-07_00-19-17_0017_1.jpg

As far as the other issue, I am still investigating why the mount didn’t slew/plate solve and sync to the exact place it should have. No big deal with this image as I can crop it out. But it’s a big deal if it keeps happening, hopefully it won’t.

Jerry

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