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Taurus widefield - Problems with LPC
Hello from Austria!
My stack shows a strong gradient and i don't get a proper correction in the tool.
I uploaded the stack for you: https://drive.google.com/drive/folders/1PRxmRdlqNGAdA47VoR4w83qEz6rgTTiX?usp=sharing
Is the material unusable?
@skanker Ouch that is a nasty gradient. I am downloading the file right now to see what I can do with it.
@skanker Whatever I try, I keep on getting strange artifacts at the bottom of the image. Did you process each individual panel before combining them to the mosaic and, if yes, what did you do?
I had a look as well and the trick here is to gradually set Light pollution correction boxes on the edges of more extreme gradients. I started with 5 around the edges and slowly adding more and checking what APP makes of it. There is quite a lot of gradients, both due to light pollution but also in color. So I creeped up onto the patches of color as well as dark and light spots. To make everything as visible for me as possible, I cranked up the saturation and stretched to the max (as you want to avoid background nebulosity as much as possible). Like so;
Setting the saturation and stretch back to a more normal level shows this;
And this is the background model APP calculated, it looks nice and gradual, also indicating the model is likely to be correct;
If you get this, save that as fits and then you can reload and try to make it even a bit better by doing the same. And then stretching more also makes for a nicer image.
First thanks for your help Wouter. It is not a mosaic but a single image (180x60sec.).
The black border was probably caused by the clip filter (Optolong L-Pro).
Also thanks for your help Vincent. That should be LPC on the highest level 🙂
I always take pictures in my garden but i have never had such gradients. Do you have any idea where these spots of color could come from?
@skanker A sorry, I seemed to have remembered that it was a mosaic but clearly I was wrong. Great pic by the way!
Thanks! Well to me this looks like you had a light source in the corner. The model APP calculated (that 3rd picture above) is a likely good representation as to where that source came from. Maybe a light of the neighbors or a bit more in the distance on that side? The color patches, I'm not an expert in why those become stronger, but I can imagine this to also happen with light pollution and an RGB sensor.
I had a bit of extra play with post processing, correcting the colors a little, adding a bit of contrast, minor crop of the edges etc. It's definitely nice data for just 60 second exposures!
Thank you for your efforts Vincent! Your input helped me a lot. I will post my results here in the next few days 🙂
That is a stunning image. Congratulation!
Very nice, great detail you got out of the background! Maybe a bit bright on the 7 sisters?
Thx 🙂 Its not the final version of the picture ! I will collect a bit more feedback and then work it into the picture.