Lake Ngaroto Star Trail, New Zealand

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Ben
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Here is a photo of 192 images taken over Lake Ngaroto in New Zealand. Stacked and edited in Photoshop. What do you think?

Can anyone notice the vertical lines artifacts? These only appear when all the images are flattened in photoshop. When viewing the blended images in photoshop before flattening they are not present. Also tried starstax but the same grid like artifacts are present. Its not present in any individual images. Any ideas of what causes it and how to prevent or remove it?

Thanks
Ben
Untitled1.jpg
 
Can anyone notice the vertical lines artifacts?
Yes. It's not your imagination.
Any ideas of what causes it and how to prevent or remove it?
No idea. I've never seen anything like it before.

Can you elaborate a bit on how this happens? You've got all the images stacked in Photoshop; what blending mode and opacity are you using? Do the artefacts become visible as soon as you flatten the image, or only after you've saved it as JPEG? Are they visible when the image is viewed at 100% magnification?

If you stack just 2 images instead of 192, and follow the same processing steps, do you get the same artefacts? If not, what about 4 images? 8 images? And so on. (I'm wondering whether it's somehow a consequence of having so many images stacked.)
 
I have experienced a similar artefact, curved rather than lines. I stacked using starstax and processed overall in lightroom. I have tried asking on a couple of places and never got a real answer. Some sort of interference pattern from the lens that is amplified when you stack multiple images is the best I have been able to speculate. I think it is worse with my canon wide angle lens rather than my rokinon, so maybe something about non dedicated Astro lenses.

In my case I have stacked high res tiffs and had the same issue.

If this generates any insights I am interested!!!
 
There is a lot of discussion on the same issue in this forum thread:

https://www.getdpi.com/forum/medium...-moire-like-pattern-assistance-requested.html

There seems to be a solution in post 19 which links it to lens corrections. The OP removed lens correction before flattening and didnt get the artefacts. Fuji apply built in lens corrections before lightroom so I'm not sure if I can remove this on my Fuji X-T3
 
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There is a lot of discussion on the same issue in this forum thread:

https://www.getdpi.com/forum/medium...-moire-like-pattern-assistance-requested.html

There seems to be a solution in post 19 which links it to lens corrections. The OP removed lens correction before flattening and didnt get the artefacts. Fuji apply built in lens corrections before lightroom so I'm not sure if I can remove this on my Fuji X-T3
I agree that that seems to be exactly the same issue.

However there may be a solution if you use non-Adobe software. Read this:
https://feedback.photoshop.com/photoshop_family/topics/disable-built-in-lens-profile
 
I agree that that seems to be exactly the same issue.

However there may be a solution if you use non-Adobe software. Read this:
https://feedback.photoshop.com/photoshop_family/topics/disable-built-in-lens-profile

Will have a look at this. I changed the lens profile correction as the wrong lens correction was in place, and the artefacts were a bit less and a completely different shape. They are less obvious with plenty of noise reduction but still there. I wonder if Fuji are more susceptible than others.

EDIT TIF.jpg
 
I changed the lens profile correction as the wrong lens correction was in place, and the artefacts were a bit less and a completely different shape. They are less obvious with plenty of noise reduction but still there.
Well, if the lens profile correction is the reason behind this - and I think that other thread made it pretty clear it is, with reasons - then an incorrect lens profile correction would surely risk make things worse! But I'm a bit confused now - if you can go back to an earlier stage in the processing and apply a different lens profile correction, can you not apply no lens profile correction? Or apply a 'correction' that doesn't actually correct anything?

I wonder if Fuji are more susceptible than others.
I don't think there's any reason to expect that. The issue seems to stem from using lens profile corrections, and all systems do that these days. The difference with Fuji is that Adobe software doesn't let you disable the corrections.

But I think it's worth persevering until you get it right. It's a lovely image.
 
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