With a new moon and the weather in Melbourne on Wednesday permitting, I decided to head out to the backyard and really focus on a few things that I've identified as needing improvement with my imaging sessions.
Firstly, I finally managed to get ASCOM pulse guiding working - having previously used the on-camera ST4 guiding and I can say that my guiding graph has never looked so good! However, I did notice that standing on any of the concrete blocks near the tripod significantly impacted on guiding, it amazes me just how sensitive we have to be with this equipment.
Secondly, the day before going out I actually took the time to sit down, research and determine the optimal gain/offset values for the QHY8-Pro. Furthermore, identifying target ADU values for taking flats. I think these two things have made the biggest difference overall and I'm thrilled with the progress I've made thus far, but there's always more to tweak and learn.
The flame + horsehead nebula has been a target I've long wanted to shoot since getting into AP, but was previously unavailable to me due to using an unmodified DSLR. With the QHY8-Pro I'm able to pick up those Ha regions quite well, especially considering I'm shooting from a bortle 8 zone.
Still learning Pixinsight, but getting more and more comfortable with it the more I use it. This time I delved into processes like DynamicBackgroundExtraction, ColorCalibration, BackgroundNeutralization and MultiscaleLinearTransform (which I must say is awesome at nuking a good portion of noise).
Overall, I'm happy with the results. There's a slight gradient coming from the left of frame which I'm guessing is due to the intense light pollution from the city. The stars in the center of frame seem nicely round, however I notice they are blurred at the edges... I'm not entirely sure what is causing this?
As always, tips/criticism is always welcome!
Total integration:
48 x 180s Subs
20 Darks/20 Flats/40 Bias (SuperBias)
Nice image David. DBE seems to deal with gradients fairly well in my images. Perhaps it didn't clean up your gradient properly because of worse light pollution? I'm under bortle 4/5 skies.
Great effort. Glad to hear you’re working though your challenges and getting that great feeling we all get when you tweek something and it makes huge improvements.
As far as the out of focus star issue on the right, I’m with Tony. Basically the center to left is in focus but because of the tilt, the right hand side of frame is not. More evidence of this is the CA you have around Alnitak. It’s not concentric and balloons out to the right suggesting that the camera is not on axis. More challenges to iron out I know but I think this one is a pretty easy one to fix.
Tony - I'm thinking it's a bit of an ask to fully clear up the intense light pollution, but I'm going to play with the parameters a bit and try for a better result if possible.
Thanks for the suggestions about image tilt, I've had a bit of a headache trying to get the camera mounted right - my field flattener has a really long thread which has resulted in me needing spacing rings and a center & tilt adjustment ring just to thread it on... I'll take a closer look and probably need to order in a custom part for a better fit. Cheers!
I like the pic. My comment, as a beginner: would be possible make the horsehead more clear? I do not if would be possible given the big and bright stars. Also learning pixinsight...
I like the pic. My comment, as a beginner: would be possible make the horsehead more clear?
Thanks for the kind words Fernando!
As for the horsehead it's definitely missing some sharp detail and I'm not entirely sure which factor affects this the most. My first guess is the optics I'm using, although my scope is FCD100 it certainly doesn't match up to some of the high end gear you see used out there. I also hazard a guess that it might be shooting from bortle 8, but that's something I'll have to ask the pros to comment on. Thirdly, more integration time would probably help as well.
I'm going to have the chance to shoot from a bortle 1 zone in the next couple weeks and really look forward to seeing the comparison and difference this makes.
I like the pic. My comment, as a beginner: would be possible make the horsehead more clear? I do not if would be possible given the big and bright stars. Also learning pixinsight...
Congratulations, Fernando
in short yes. more subs always helps increase SNR allowing for better contrast. In this case cropping out the brighter stars to focus on the horsehead more, with more subs, would allow for better stretching to brighten the red nebulosity and boosting contrast to bring out the head more prominantly. certainly doable. its part of the fun of astrophotography, learning strategies to improve your shots.
Specifically though there's little I'd change with this shot as it stands. the brighter nearby features help highlight the difficulty in bringing the head out of the darkness without bloating highlight areas. cropping to the head alone here might not have enough depth and details yet in the data and would make it less dramatic.
Hi David what a nice prelude to your image. They say that a picture is worth a thousands words but your three hundred and sixteen words are definitely worth a picture. From the sounds of things you have managed to overcome a few hurdles along the way which is always a great feeling. Those eureka moments are what keeps us going. This hobby is like one giant jig saw puzzle with thousands of pieces and bit by bit we all piece together our own puzzle until one day it's hopefully complete. Then we share our result with others who have an understanding of the challenges and triumphs we experienced in order to get there. Well done!
Hi David what a nice prelude to your image. They say that a picture is worth a thousands words but your three hundred and sixteen words are definitely worth a picture. From the sounds of things you have managed to overcome a few hurdles along the way which is always a great feeling. Those eureka moments are what keeps us going. This hobby is like one giant jig saw puzzle with thousands of pieces and bit by bit we all piece together our own puzzle until one day it's hopefully complete. Then we share our result with others who have an understanding of the challenges and triumphs we experienced in order to get there. Well done!
Thanks for the kind words . I certainly agree with you about it being a giant jigsaw puzzle - I find learning and figuring out how each piece fits incredibly rewarding! There's always something to learn from the pictures we take, but also being able to appreciate that "hey, I took that damn image, wow!" is also important. Cheers!
. I certainly agree with you about it being a giant jigsaw puzzle - I find learning and figuring out how each piece fits incredibly rewarding! There's always something to learn from the pictures we take, but also being able to appreciate that "hey, I took that damn image, wow!" is also important. Cheers!
