UPDATE FROM MABULA
I have had a very rough 2 months unfortunately health wise. I was struck 3x in a row with bacterial infections. The second infection occurred  after a routine hospital checkup and I became very sick. I had to rest and take a lot of antibiotics. Once I was recovering and restarting work 1 month ago, I again became sick. The infection was not yet gone, so even more antibiotics and rest was needed. Needless to say, it took a lot of my energy and I needed a lot of rest.
Finally, the infection is really gone and my energy is coming back step-by-step now and I have started work again. I am terribly sorry to have kept you waiting for support. I will address all outstanding questions and e-mails step-by step and will be on the forum daily from today.
APP 2.0.0-beta47 will come soon as well, a lot of work was already completed before I became very ill, so the release is also nearly ready for you. Beta47 will be much faster actually. Many workflows will be more than 2x faster, mosaics can even be 10x faster than before because registration really received a major boost... all compared to beta46. Â Before I release it, I will make sure that everything is working properly and then I will release it.
Here's a bit of a strange one. When I merge three panels, I am seeing light appearing towards the edge of panel 2 which when I merge panel 2 and 3 is not there, this only occurs when I merge Panel 1 into the mosaic.
Panel 3 - Top
Panel 2 - Middle
Panel 1 - Bottom
Here's a screenshot of the outcome with all three panels, I am seeing lightness on the bottom right of panel 2 which is not there in the 2 panel mosaic
And same data but just a 2 Panel (Panel 3 and Panel 2) does not show this light at the bottom of panel 2
This only seems to affect the Ha data portion, the SII and OIII seem to be fine, each of the panels on their own also look fine:
Panel 3:
Panel 2:
Panel 1:
I am going to crop the images to remove the stacking edge artifacts to see if it makes any difference, but I have never had to do this before ever, so not sure it will make a difference.
I have tried MBB from 10% to 15% (my overlap is 10%), I have also tried LNC 1/2 with 3 itterations, and it made no difference.
Regards
Simon
try LNC 4 with 3 iterations
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LNC4 itterations 3 made it worse
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It is definitely something within the LNC process as this is the same mosaic without any LNC/Iterations
After further experimenting.
1. If I perform the LNC during the integration of each panel before Mosaic, and then do not perfom any LNC during the mosaic integration, I do not see the issue
2. If I perform LNC during the mosaic integration, this is where I see the issue (whether I've performed LNC on the individual panel stacks or not)
Hi Simon @stastro,
Sorry for my late response here, yes indeed, this is a shortcoming of the current LNC implementation. LNC trys to have the gradients removed or at least blend into each other in the different panels. Apparently, in this case, an articial gradient is introduced to have the gradients blend better, or at least it should. LNC in it's current from is NOT in principal a gradient remover allthough it does it on many cases. If such an artifical gradient is introduced, it can always be removed easily with the Remove Light Pollution Tool, can't it?
For LNC 2.0 I intend to have this work much better.
Mabula
@mabula-admin Yeah, I have not tried the LP removal tool because it is not LP, and the contrast between the two frames (Central and Lowest) is way more than Light Polution artifacts. I will have the finalised data for the lower panel tonight and will re-test.
A quick question though, does LNC make any refference to total exposure time when performing the correction? I have noticed significant differences on panels on my 16 panel mosaic, based on total exposure time, some panels appear darker than others and I tried No LNC, LNC1/3, 2/3, 4/3 etc. I don't have the luxury of obtaining any more data on that mosaic now until June, so work will resume on that next year
Hi Simon @stastr,
Okay.
No, the LNC calculation does not take into account the exposure times of the different panels nor the total exposure time of everything combined. Could the big differences be result of varying sky conditions when shooting those panels?
Mabula
@mabula-admin I thought about that too, however not performing an LNC on the Ha data proves that is not the case, and looking at each of the panels individually seems pretty even illumination across the panels. And the fact this only happens on the Ha panels, the OIII and SII panels work perfectly. Ended up having to run the mosaic through twice, one without LNC and one with as LNC seemed to work well on the OIII and SII data, this was the final image with
Ha: No LNC
OIII: LNC 1/3
SII: LNC 1/3
Hi Simon @stastro,
Okay excellent ! That is an awesome result 🙂
Glad you were able to complete this mosaic successfully !
Cheers,
Mabula
