Quote:
Originally Posted by alistairsam
Hi Rex,
Looks very good, lots of detail in there.
I see you've used the CLS LP filter but with an F4, 10 minute exposures gather a lot of LP even with the best filter and after 4 minutes, there's not much gain in signal. its the brown tinge.
I used to use an 8" F4 and have played around a bit with an IDAS LPS-P2 LP filter. so tested different exposure lengths for the same target and realized that the details in a 10min aren't that different from a 5 minute which is only slightly better than a 3 min.
you can easily remove it with processing software like Startools and PI, attached is a quick wipe in startools.
I'd suggest keeping your subs to 3 to 5 minutes and increasing the number of subs.
That would help reduce LP showing up.
Do experiment if you get the chance.
try 10x3 min exposures and then 6 x 5min and compare. well worth it.
or even single subs.
your guiding and coma correction are perfect.
Cheers
Alistair
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Thanks Alistiar, some very interesting information. Fortunately for me, the brown in this case comes from my poor processing skills, I think. I only use the CLS-CCD clip filter because where I used to live a couple of years ago I needed it. Where I live now is not perfectly dark but pretty good. M31 is easily visible naked eye, averted vision it is very visible. Thats not to say that LP hasn't played a role in the way this image looked. Just as I finished processing it, I thought it was too red, so I did a selective colour adjustment to change the reds. This is where the orange and brown came from. I have attached the same image to the first post from before I did that final colour adjustment. Please feel free to tell me I am wrong and that you still see LP, as I am really only just starting my astroimaging journey. My processing skills are so good I can make an image look like it is LP affected.
Quote:
Originally Posted by JZ
Another nice shot Rex. Alistair has some interesting comments!
Interesting to see what startools can do too.
I have certainly learned from this!
Cheers,
Ross...
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Thanks Ross.