Couple of things here, first of all it is faint, so faint it is not funny; and as a result I am gonna need to do really long subs to get this one out bright. That means sorting out some minor flexure issues I have with the scopes. Second, Alex I owe you an apology. My RC secondary dewed up last night for the first time. Only really late in the piece and just enough to dim the images. Time for a dew shield I think or one of my dew straps.
Probably the Helix is one object where the aperture and focal ratio of the scope can make a big difference.
No doubt longer subs would help to bring out more of the detail within The Helix, perhaps even to pickup the cometary globule type structure that exists within it.
Not sure about the colour, it really is such a subjective thing, however I think this looks too red and maybe the nebulosity should be more yellowish.
I know it is unfair to compare a 8" GSO RC with the Hubble but I think the colours in this attached Hubble image are the ones to strive for.
How does it stack up displayed at a decent size..?
As far as the colour goes, Trevor has it a bit wrong (sorry Trev), that Hubble shot is a narrow band filter composite where as you are imaging it in RGB so your colours are quite ok actually.
Trevor I would love to get that sort of colour. I think Mike has got it right though, I think that is a narrow band. Great image though. I can jsut see the cometary globules in the image but longer deeper images will provide more detail.
Mike, the image up full scale is a bit noisy and suffering from the dew on the secondary. Stars are slightly eggy too, but not too tragic. I am planning how to attack this target. When the QSI arrives I am gonna hit this and see how it goes. No flexure problems that is for sure.
Another nice image Paul. More data would have brought out the detail in the outer ring and a bit more in the core.
Dewshield...... I use an 8" orion dewshield from bintel on my VC200 and it works very well. They are nicely made,solid construction, quite light, inexpensive and do the job well and lay out flat for transporting.
coming along well so far, 2 things about this object it needs the longer FL to make it an interesting object to bring out the knots etc (which are showing here)and if you really want to do a top notch job, you are going to have to commit 6+ hours to it. theres just no substitute for lots of data.
I think with this one there may be something to gain from not over doing it on the exposure time. The subtlety of the nebula is enhanced by it not being high contrast in the image. The detail is still there, without being forced on you.
Totally agree guys, longer exposures and long imaging runs should make this image so much nicer. This is what I was thinking and I am glad to read that you guys think the same thing. It will be a project for this winter I think.
Doug, might go and look at their selections of dew shields. Thanks for the tip.
As far as the colour goes, Trevor has it a bit wrong (sorry Trev), that Hubble shot is a narrow band filter composite where as you are imaging it in RGB so your colours are quite ok actually.
Very nice work
Mike
Thanks Mike, it looks so different that the penny should have dropped.
As a matter of interest, what wavelengths do you think the Hubble image would have used and would it be realistic for an amateur to have a crack at it, it really is an amazing image.
Quote:
Originally Posted by Paul Haese
Thanks guys,
Trevor I would love to get that sort of colour. I think Mike has got it right though, I think that is a narrow band. Great image though. I can jsut see the cometary globules in the image but longer deeper images will provide more detail.
Hi Paul, there are some guys posting on this forum, whose work regularly seems to extend the boundaries for others to aspire too. As a mainly planetary imager I suppose my expectations of some of you have grown extremely high.
I pose the same question to you as I did to Mike, do you think it would be possible for an amateur to create a reasonable narrow band image of the Helix or would the capture time required be just too long.
Thanks Trev, appreciated. Yep wanting to get the 12 for sure, or if time and money will extend in the future I think I will go with a much larger RC.
Trevor (quark) (boy this is getting confusing; too many trevors. LOL). I am not sure about narrow band. I suppose it is possible given that the HST palette is well known. Not being an expert in this area I could well be wrong and maybe Mike could answer this or someone like Fred V. Interesting if one could get this same sort of colours.
Nice image Paul.... I told you that secondary dews up in the right conditions!! Using SII Ha OIII for RGB would give you the same colours as the Hubble image, however your exposure times would have to be fairly insane... I would be looking for 30 minute subs, and binning SII and OIII 2x2 to increase signal... 3 hrs Ha/OIII 4~5hrs SII and using Ha for LUM you MIGHT get a similarly bright, colourful image...
Paul, with your setup you might want to try for 20 minute subs, maybe 30 if you can (given your mount, I would think 30min subs would be EASILY achievable)
Looks like a good start, but much longer exposures are required to really pull out the outer shell..
Alex, no problems with the mount. I just have some flexure issues that prevent those length subs at present. I will sort this out and then I will be getting very long subs on this particular target. One more really clear night would help too.
As a matter of interest, what wavelengths do you think the Hubble image would have used and would it be realistic for an amateur to have a crack at it, it really is an amazing image.
Trevor
Hi Trevor yes I had a crack 3 years ago with the 6" Starfire at producing a kind of imitation of that Hubble shot:
Am waiting for the QSI delivery and then I will be hunting this sucker down. The QSI has the same KAF8300 chip that you have in your FLI beast. I am looking into Ha filters. I was going to go with a Astronomiks Ha filter, what are your thoughts?
