[RCC] North America Nebula

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Cfeastside avatar
Was wondering what you all think of this shot.  My first time imaging a nebula and this was also the first time with my new asi294 mc pro, APT, and electric focuser.  I know this is highly subjective, but do you think its too contrasty?  Im pretty stoked with how it came out as i didnt really kmow what to expect.  Im not too stoked about the large bloated stars, could reduce those.  I did reduce the bg stars a bit in PS.  for know i do like having them vs no stars or very few stars.  

if you zoom in to 100% or more the stars look slightly blurred as if out of focus.  Thats what i thought but looking at the subs quicly one at a time there is drift occuring between subs.  Im hoping its due to bad cable management which i have addressed.   My polar alignment was sub arc minute per phd2. So i dont think its due to that.   

Thanks for any comments and interested with your take.  


wo gt81 with asi294 mc pro osc
uniguide 32 with asi 224 as guide cam
cgx
lights 62x180s
darks 40
dark flats 40
flats 40
APT PS

Olaf Fritsche avatar
Congratulation for this wonderful first image with a new technique! I suppose there are great things to come!

I would keep the big stars just the way they are. To me they look natural. Maybe you could reduce  the vast number of small and tiny stars? This would make the picture look less wild. (Just my personal taste vs nature.) 
What I would definitely do is rotating the picture clockwise so that you can recognize the outlines more easily.
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Cfeastside avatar
@Olaf Fritsche thanks for your comments!  I i think you might be right about the orientation.  Its growing on me.  Id like to do a mosaic of this and pelican nebula together but rotated.  
rhedden avatar
I'm imaging NGC 7000 right now as well, and I plan to go with something closer to the first orientation you posted.  I like to play around with unusual orientations and framing.  One of these days I am going to post an upside-down Horsehead Nebula, just to bother people. smile

In terms of constructive criticism, I would point out the size/shape of your stars first.  When you stretched the data to brighten the nebula, the stars became stretched so much that they are enlarged and have overexposed cores that turned bright white in some cases.  To get a more pleasing image, you could try masking the stars during processing so that they are not stretched as highly as the nebula is.  I highly recommend that you learn a star-masking technique, as it is essential to your workflow.   You could also try a star size reduction procedure, depending on what software you like to use.  Experienced DSO photographers will always look for stars that are 1) not bloated due to poor guiding/seeing,  2) round, right to the edges/corners,  3) not overexposed or overstretched, and 4) lack color aberrations, like pink rings around the edges.  If you look through the current Top Picks list, you should see some examples of images with really nice star shapes and colors.

Hope this advice is helpful!
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Cfeastside avatar
@rhedden thanks for suggestions!  Youre right about the size of the stars i was wondering the same thing or maybe im over exposing a bit

i use APP but there is no star masking that im aware of.  At least not yet.  I tried to control that a bit with its highlights adjustment slider but didn’t produce the desired result.  I did try and tame them in PS but too late there.  Not sure how to approach this without foing to pixinsight.  Ill have to. Look into it a bit more
Cfeastside avatar
I stand corrected.  AAP newest beta has a star reduction tool now and it looks awesome.  Ill be downloading that tonight.
Ross Salinger avatar
I think that you aren't so much over exposing as over stretching the result. Using PI on my widefield shots I have to be really careful about the stretch to avoid losing star color. PI also has an erosion filter that makes a huge difference. If AAP has equivalents (I think it does) then those would be the things to try. 
Rgrds-Ros
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