I looked through my images recently and discovered that I have never done a monochrome image of M20. I have a fairly reasonable image done with the modded 40D. So with that in mind and whilst waiting for the return of the STXL I thought I would do the Trifid with the TSA102. I will do one with the RC12 if time permits this season once the camera returns.
This will most likely be the last deep sky image I take with the TSA as it is being retired for an FSQ. It has been a great scope but I want a wider field of view for some of the more extended objects out there.
One thing I noticed is that there is lots of very faint gas to the right of the nebula that I had not seen before. I wonder if this gas is Hb or is this really faint Ha? Maybe some of the learned out there can inform me.
Bottom right of the image is part of the Lagoon nebula I think.
Nice shot, Paul. Would love to see what you can do with the longer FL of the 12". I think I have a wide Ha of that region. I'll check it when I get home to see if it shows the faint stuff you captured to the right.
Ha and Hb are both emitted by ionised hydrogen. Hb is just a transition from a more excited state.
I just did a quick plate solve via astrobin on an image I did last year that included the faint stuff in this region and I just got stars in the result.
Nice image by the way. As Rick says, its worth have a look at someones wide field Ha image if there are any around as the place is sodden with the stuff
Last edited by DJT; 15-07-2014 at 05:53 PM.
Reason: removed images, not wishing to hijack
Nice shot, Paul. Would love to see what you can do with the longer FL of the 12". I think I have a wide Ha of that region. I'll check it when I get home to see if it shows the faint stuff you captured to the right.
Ha and Hb are both emitted by ionised hydrogen. Hb is just a transition from a more excited state.
Cheers,
Rick.
I think the 12" will produce much more interesting results. Interesting about the Hb.
Quote:
Originally Posted by Star Catcher
Yeah I like that one Paul, got a bit of 3D depth to it.
Ted
I have seen a few of images of this over the years that look very 3D. I am hoping I can emulate some of those images.
Quote:
Originally Posted by strongmanmike
Naah couldn't care less, seen one jet seen'em all, besides I only see averted imagination jets
Nice image Paul, looks slightly out of focus though
Quote:
Originally Posted by LewisM
I do agree with Mike on the larger version - definitely seems just SLIGHTLY soft focus.
Mike and Lewis, focusmax does not lie. When you are automated it does not make mistakes. The focus is only affected by the seeing on any given focus run and every 50 minutes I have the system focus. I don't use any image where the FWHM is above 3".
Most likely Mike is just yanking my chain here, especially with the wink at the end of the sentence.
However, the HFD for focusing has been affected by some pretty average seeing in the last month or so. Instead of getting readings of HFD at around 2.5 arc seconds for a focus run it has been around double that. So if you think this looks soft then it is most likely seeing. Though I don't agree, this is not soft to me on a 4K screen.
Not sure how there can be any Hb in it if you used a Ha filter? Hb is at the blue-ish end of the spectrum.
Kevin if I am using a 5nm filter is there not a chance of some Hb seeping in? I thought that unless I was using 3nm filters then some Hb is still captured. Am I wrong in thinking this?
I agree with your comments on focus. Like I said above focusmax does not like or screw up once it is set. I have been using the same focusing settings and v curves for 12 months or so now and produced lots of sharp images so I doubt anything has changed.
Great stuff Paul... Heaps of detail and I can't wait to see what the RC can do. It got me thinking and I rummaged around and found 1 M20 Ha sub. It was all I could find as on this night the cloud rolled in and it was the only decent one of the bunch. I think it shows that there is a lot of Ha in this area. I agree with you that the focus seems fine.
So 1 X 10 min 12nm Ha sub @ F3.6 bit noisy but it shows the Ha in the area
Kevin if I am using a 5nm filter is there not a chance of some Hb seeping in? I thought that unless I was using 3nm filters then some Hb is still captured. Am I wrong in thinking this?
You won't get any Hb, Paul. As Kevin said, that's way down in the blues. A 5nm Ha filter will also get NII however, and there is often some of this about. Ha has a wavelength of 656.28nm and NII is at 658.36nm. A 3nm filter cuts out the NII as I found to my chagrin when imaging the Helix. A 5nm filter would have got me combined Ha+NII data and delivered good SNR much faster...
You won't get any Hb, Paul. As Kevin said, that's way down in the blues. A 5nm Ha filter will also get NII however, and there is often some of this about. Ha has a wavelength of 656.28nm and NII is at 658.36nm. A 3nm filter cuts out the NII as I found to my chagrin when imaging the Helix. A 5nm filter would have got me combined Ha+NII data and delivered good SNR much faster...
Cheers,
Rick.
Quote:
Originally Posted by cometcatcher
Yeah Hb is up around 486.1nm. I'd like to see more NB imaging with it. Must not be popular for some reason.
Ah of course. I had that ballsed up. It was NII I was thinking of. Thanks for the clarification.
Yeah Hb is up around 486.1nm. I'd like to see more NB imaging with it. Must not be popular for some reason.
Hb emission is about a third the intensity of Ha. It requires more energy to kick the electrons up another shell. You can simulate the Ha+Hb by adding red and blue in appropriate proportions... to give the magenta that we all know and love
Sorry for converting your deep sky image thread to a physics discussion, Paul
Nice detailed result Paul, very smooth for 8 subs, how does that happen, is it the good signal in the area, the camera, Callibrations or processing ? I guess a bit of everything or could be something a little more particular? Just curious.
Always an interesting thread as asual
Hb emission is about a third the intensity of Ha. It requires more energy to kick the electrons up another shell. You can simulate the Ha+Hb by adding red and blue in appropriate proportions... to give the magenta that we all know and love
Sorry for converting your deep sky image thread to a physics discussion, Paul
Cheers,
Rick.
No problem Rick, I wanted to know anyway.
Quote:
Originally Posted by stevous67
Hello Paul,
Just wondering what has happened to your STXL?
Steve
It seems to have developed a clocking problem. I hope to have it back this weekend as it is being worked on now I think. It will go back to Peter and then he will hopefully deliver it to me over the weekend.
Quote:
Originally Posted by astronobob
Nice detailed result Paul, very smooth for 8 subs, how does that happen, is it the good signal in the area, the camera, Callibrations or processing ? I guess a bit of everything or could be something a little more particular? Just curious.
Always an interesting thread as asual
Well Bob I am going 30 minute subs. The scope has a small diameter so I need to collect signal for a long time. So having high signal to noise helps a lot. Calibration frames are important too. I typically use lots of masks to process my images and these days almost never use smoothing, so I am selective about sharpening, high lighting and protecting the background from the introduction of noise. All of that put together makes for smoother images.
