Quote:
Originally Posted by ausastronomer
I don't mean to hijack this thread but I am seeking some guidance here. I am asking it here because there are some knowledgeable imagers who have contributed to this thread that can probably give me an accurate answer.
I am purely a visual observer. After destroying many rolls of Kodak Ektachrome in my Olympus OM-1 on a 6" Newtonian back in the early 1980's I decided astrophotography wasn't for me and I was going to spend the rest of my astronomy days as a purely visual observer and so it has been.
Peter's image of M20 is excellent. However the stars in HN40 are "burnt out" and difficult to distinguish as a multiple star complex as such. That having been said it's probably the best I have seen so far. I have seen many other really nice amateur images of M20 over the past decade but in every case the multiple star complex HN40 is not distinguishable as a multiple star complex as such, and is basically a "bright blob".
Is this because long exposure times are required to get the required detail in the nebula complex itself which cause the 2 brighter stars in HN40 (A & B) to burn out, or become overexposed. If someone was to set up their exposures so as to properly capture HN40 as a multiple star complex (4 stars) what would happen to the image quality on the rest of the nebula?
Cheers,
John B
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The difficulty is one of blending the stars to still look natural, despite a much shorter exposure time (which will indeed resolve the group).
When you then try to match the brightness levels... noise in the shorter exposures also becomes a problem...
Lastly I did indeed try short exposures (2 minutes) to better resolve the core stars...they were still too bright!