Hi guys, in the past few months I have had various things on my plate. I got married in March and since then I have not done much in the way of imaging. In the meantime I wanted to sort out an off axis guider for my camera, and after being sent a broken one I am finally where I want to be with my guiding. I am now guiding through a TS 9mm OAG with my SSAG.
The reason I wanted to be using an OAG was because around a year ago I bought narrowband filters and posted an image here. Martin Pugh commented on the image and said that for narrowband imaging long subs were better. This made sense to me because then you can get long integration times without too much diminishing returns on stacking lots of frames.
This image is up too 11.5 hours of Hydrogen alpha in 30 minute subs. I plan to make a bi-colour image with some O3 data eventually but im not sure that I am done with the HA yet.
Critique is always welcome, my imaging has come a long way in the 2 years I have been doing this and its due to people telling me whats wrong with images.
Looking very nice, Peter! You have the faint outer regions starting to show up nicely.
I noticed in the larger version that there are a few camera artefacts - defective columns, hot pixels / cosmic rays, etc. Seems a bit surprising given your 23 subs?
Looking very nice, Peter! You have the faint outer regions starting to show up nicely.
I noticed in the larger version that there are a few camera artefacts - defective columns, hot pixels / cosmic rays, etc. Seems a bit surprising given your 23 subs?
Ahh yes the defective column I can sort out I dont think I applied my darks to a few images that were after the meridian flip last night. The cosmic rays and hot pixels may be how I stacked the images (I plan to do it differently later) I stacked each nights images and then combined them in a separate stack, I think I may end up with a better result stacking them all at once.
Great capture, Peter. Enjoyed the faint extension you've presented. I'm looking forward to seeing the end result with OIII added (and possibly some RGB starts to balance the image). Good work.
Nice work, Peter. You've captured a lot of very faint stuff.
Quote:
Originally Posted by Peter.M
Martin Pugh commented on the image and said that for narrowband imaging long subs were better. This made sense to me because then you can get long integration times without too much diminishing returns on stacking lots of frames.
This is correct but the reasoning is wrong. Long exposures are better for narrowband because the signal is relatively weak and the camera read noise swamps it in short exposures.
That's a great result. With longer subs you need to use even colder temps on your CCD. So if you are not already maxing out the temp it can do it would pay to increase the cooling as much as possible. Especially taking advantage of the extra cooling that winter already gives you.
Also depending on your scope I find I get a good gain using 2x2 binning on Ha very often. It depends on the final use for the Ha. If you are doing narrowband and intend to use to show detail then perhaps not. But you could do a blend of 1x1 and 2x2 with the 2x2 picking up more of the outlying super faint neb. You have almost all of it but there is a tad more there. I used a 17 inch scope and 2x2 binning with a .6x reducer to really show it all and its quite extensive.
Great capture, Peter. Enjoyed the faint extension you've presented. I'm looking forward to seeing the end result with OIII added (and possibly some RGB starts to balance the image). Good work.
Thanks Jase, I will see what the stars look like after making a synthetic green from O3 and HA but yes RGB stars might be in order.
Quote:
Originally Posted by RickS
Nice work, Peter. You've captured a lot of very faint stuff.
This is correct but the reasoning is wrong. Long exposures are better for narrowband because the signal is relatively weak and the camera read noise swamps it in short exposures.
Ahh yes that makes sense, less signal in HA images to overcome the readnoise.
Quote:
Originally Posted by Peter Ward
I've been hacking away at the Helix myself and can say from my also-rans results so far that's an impressive image. Nice one
I have seen the images you have posted of the helix and that scope has some great resolution. Im sure your rendition will be great!
Quote:
Originally Posted by Shiraz
Crikey Peter - that's a beautiful deep image. regards Ray
thanks Ray, Im glad you like it.
Quote:
Originally Posted by marc4darkskies
Very impressive depth in that image Peter! Looks like you're headed for a mega data image! Look forward to seeing the final result!
Cheers, Marcus
Thanks Marcus, I love the images you present on here so that is high praise. I am very happy that I am able to setup every night and get results, thank god for alignmaster it is the only reason I can get 30 minute subs.
Quote:
Originally Posted by cosmophoton
Nice work Peter! Do you have images of your homemade carbon fiber telescope?
Cheers,
Luiz
Thanks, I will try to take an image tomorrow for you, it is pretty basic though. I purchased a packaging tube and wrapped it in carbon layer by layer.
Quote:
Originally Posted by Paul Haese
Looking good Peter, very deep.
Thanks Paul, lets see how much of the halo is left when it gets made into colour.
Quote:
Originally Posted by gregbradley
That's a great result. With longer subs you need to use even colder temps on your CCD. So if you are not already maxing out the temp it can do it would pay to increase the cooling as much as possible. Especially taking advantage of the extra cooling that winter already gives you.
Also depending on your scope I find I get a good gain using 2x2 binning on Ha very often. It depends on the final use for the Ha. If you are doing narrowband and intend to use to show detail then perhaps not. But you could do a blend of 1x1 and 2x2 with the 2x2 picking up more of the outlying super faint neb. You have almost all of it but there is a tad more there. I used a 17 inch scope and 2x2 binning with a .6x reducer to really show it all and its quite extensive.
Greg.
I am running the camera at -30 at this time of year. It is sitting at around 55% cooling power maintaining that but I dare not push it harder. As for binning, this image is at 1.4 arc seconds per pixel. I hadn't thought about binning the HA. I would wonder if you would lose detail by doing so.
compiling the outer halo from binned data is interesting, but then I would feel like im missing out on noise reduction on the rest of the image.
Nice one Peter. You can see a lot of the faint extensions and the central resolution on the pillars is excellent too.
Thanks Marc, the pillars started taking more shape after about 4 hours which I found interesting.
Quote:
Originally Posted by strongmanmike
Looking good Peter, stick with it, a masterpiece awaits
Congratulations on shackling yourself too (did you already mention this BTW...)
Mike
Thanks Mike, and yes I had mentioned the missus in another thread but since then I have had numerous problems with my scope setup and I am only now producing results that I am happy with again.
What a marvellous image, especially from only 6 inches of aperture! 30min subs with a HEQ5, that is really something. Do you have a permanent obs setup by any chance?
What a marvellous image, especially from only 6 inches of aperture! 30min subs with a HEQ5, that is really something. Do you have a permanent obs setup by any chance?
Thanks Richard, I dont have a permanent obs. Thats part of the reason I am happy to be able to produce these results. Good polar alignment software, an off axis guider and alot of patience is all you need!
Thanks Richard, I dont have a permanent obs. Thats part of the reason I am happy to be able to produce these results. Good polar alignment software, an off axis guider and alot of patience is all you need!
Yes Richard this very conversation came up this week at my observatory. I quizzed Peter on his speedy setup times and the software he is using to get fast setups. He answered this while sorting out an issue he was having at the time. His attention to detail is very good. We have discussed many of the issues he has sorted himself over the last 12 months or so and it is a credit to him that his patience has won through. Not only did Peter have problems with the OAG, he had problems with the mount and there have been several other minor issues to resolve along the way. He also made the carbon tube himself too and also changed over the drives on the EQ5 to belt driven. Its a great little setup that he has and it gets respectable results. Keep at it Pete, you're producing good images.
Yes Richard this very conversation came up this week at my observatory. I quizzed Peter on his speedy setup times and the software he is using to get fast setups. He answered this while sorting out an issue he was having at the time. His attention to detail is very good. We have discussed many of the issues he has sorted himself over the last 12 months or so and it is a credit to him that his patience has won through. Not only did Peter have problems with the OAG, he had problems with the mount and there have been several other minor issues to resolve along the way. He also made the carbon tube himself too and also changed over the drives on the EQ5 to belt driven. Its a great little setup that he has and it gets respectable results. Keep at it Pete, you're producing good images.
Thanks Paul, It has been a long road but I am happy to be producing images that I am happy with at last. Thats the main thing isn't it!
thanks Ray, Im glad you like it. 
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