Is that diffraction spikes I see on the brighter stars?
Thanks mate; yep there's definitely some kind of artefact around the brighter stars that resembles diffraction spikes. I'm not sure what it is, but I don't mind it to be honest... if only they were bigger :p (yes, I'm one of those heathens that likes diff spikes)
Quote:
Originally Posted by strongmanmike
Colour looks good Lee
Mike
Thanks Mike!
Quote:
Originally Posted by alpal
Hi lee,
nice job on the colour version.
I am surprised that you could get such a good picture with
only 120mm of aperture.
well done
cheers
Allan
Thanks Allan; appropriate sampling, sensitive camera, dark skies and an unobstructed 120mm does alright I think. I'm happy with the compromise, having less things to constantly tweak, and the budget won't go any higher than a 120mm triplet.
I've uploaded a corrected version to Astrobin now, fixing the colour a bit.
I continue to be surprised by how blue NGC 300 is, not just in your shot, which is great, but in APOD and ESO publication shots. I wonder a bit whether this is "We always throw the best looking person in the tribe into the volcano, and we always make NGC 300 very blue. Otherwise the crops won't grow, everyone knows that", or whether it is undergoing a round of intense starburst activity. There's no sign of tidal distortion that might suggest a recent encounter with another galaxy. I should love to know. Wikipedia says it forms a gravitationally bound pair with NGC 55. That might do the trick!
Thanks mate; yep there's definitely some kind of artefact around the brighter stars that resembles diffraction spikes. I'm not sure what it is, but I don't mind it to be honest... if only they were bigger :p (yes, I'm one of those heathens that likes diff spikes)
I continue to be surprised by how blue NGC 300 is, not just in your shot, which is great, but in APOD and ESO publication shots. I wonder a bit whether this is "We always throw the best looking person in the tribe into the volcano, and we always make NGC 300 very blue. Otherwise the crops won't grow, everyone knows that", or whether it is undergoing a round of intense starburst activity. There's no sign of tidal distortion that might suggest a recent encounter with another galaxy. I should love to know. Wikipedia says it forms a gravitationally bound pair with NGC 55. That might do the trick!
Best,
Mike
Thanks Mike, appreciate the feedback and the info, very interesting.
I always struggle to get colours right and it's hard to know what's right, so when I don't know I'll usually go with convention unless I've got a good reason not to.
The one in the original post is definitely too blue.. I tried to reduce a green cast and ended up going blue instead of magenta. I fixed it up in the Astrobin version.
Thanks again!
Quote:
Originally Posted by topheart
Very nice rendition!
Tim
Thanks Tim!
Quote:
Originally Posted by Camelopardalis
I was about to say I kinda like it
haha. Ah, good to find another heathen.
I'm a bit low on targets at the moment so I may continue to add more to this. The colour data is particularly poor, I really need more than 5 subs per channel.
It's very detailed and beautiful Lee - what a result. The colour is sure a bit tricky, because this is fairly dim, but you have nailed it. interesting to see how you go with more data.
It's very detailed and beautiful Lee - what a result. The colour is sure a bit tricky, because this is fairly dim, but you have nailed it. interesting to see how you go with more data.
Thanks Ray, appreciate it! :-) I definitely need more colour data at the very least.
I had a quick play last night, spawned by Mike's comments and some I received elsewhere and produced one that's a lot less blue than is typically done for this subject. Thoughts on it? Ignore the over-saturated background galaxies.
Got a couple of hours more data last night and reprocessed it (see original post, or Astrobin). The colour is a bit different, hard to say what's right and wrong given the colour variations I've seen, but I think I'm happier with this.
Right now I'm gonna say I'm done with it... mostly 'cause I'll never think it's right and I want to move onto other targets :p
Last edited by codemonkey; 17-10-2015 at 04:14 PM.
Thanks Allan; appropriate sampling, sensitive camera, dark skies and an unobstructed 120mm does alright I think. I'm happy with the compromise, having less things to constantly tweak, and the budget won't go any higher than a 120mm triplet.
I've uploaded a corrected version to Astrobin now, fixing the colour a bit.
Hi Lee,
You've done so well on a tough target.
I think I'll have a go tonight even though a 5 minute test shot
I did - that was a bit out of focus hardly revealed anything.
see the attached test shot.
I noticed you mixed 1x1 binning & 2x2 binning.
I think I'll have to do 2x2 binning & 15 minute subframes to pick up anything in those faint arms.( for all LRGB )
A 30 minute subframe of Ha binned 2x2 would also be nice.
I am undecided on how to do this one?
I'm lucky to have dark skies, which makes this a bit easier for me. Hard to say what's appropriate for you without having a lot more information. All I'd say is try and find out how long you need to expose for before you're sky limited (at least for luminance) and then aim for that. If you go above that you're risking more subs to environmental issues and all you're getting for your efforts is reduced dynamic range (blown out stars).
I initially did 2x2 for RGB because for me to get sky limited in the blue channel I need 38min exposures when binning 1x1, and I'm not prepared to do broadband subs that long.
I ended up with a lot of artefacts around the blown cores of the brighter stars with the 2x2 images, so I went back to 1x1, which helped with that. I could have (to some extent at least) processed it out, but I'd prefer not to have to. I think I'll probably just stick to 1x1 in future... if I throw out some resolution by software binning the results don't seem to differ much so I don't think it's worth it for me.
For your reference I've attached a single 480s luminance sub, stretched to hell and back.
I'm lucky to have dark skies, which makes this a bit easier for me. Hard to say what's appropriate for you without having a lot more information. All I'd say is try and find out how long you need to expose for before you're sky limited (at least for luminance) and then aim for that. If you go above that you're risking more subs to environmental issues and all you're getting for your efforts is reduced dynamic range (blown out stars).
I initially did 2x2 for RGB because for me to get sky limited in the blue channel I need 38min exposures when binning 1x1, and I'm not prepared to do broadband subs that long.
I ended up with a lot of artefacts around the blown cores of the brighter stars with the 2x2 images, so I went back to 1x1, which helped with that. I could have (to some extent at least) processed it out, but I'd prefer not to have to. I think I'll probably just stick to 1x1 in future... if I throw out some resolution by software binning the results don't seem to differ much so I don't think it's worth it for me.
For your reference I've attached a single 480s luminance sub, stretched to hell and back.
Thanks Lee,
Your dark skies pulled the arms out of noise.
I'll see what happens with a 2x2 Luminance at 10 minutes & judge what to do from there.
This is looking fantastic Lee. That 120 is focusing the photons beautifully upon your sensor. I'm out again tonight collecting more data. Missed last night due to daddy daycare duties.
I'm waiting for orion area to get up, for my rig there is not much in the sky of interest at the moment.
This is looking fantastic Lee. That 120 is focusing the photons beautifully upon your sensor. I'm out again tonight collecting more data. Missed last night due to daddy daycare duties.
I'm waiting for orion area to get up, for my rig there is not much in the sky of interest at the moment.
Thanks mate! Friday night was awesome, at least over here... last night was about average.
Did you end up getting anything? Clouds were due to roll in around 12; they appeared on the horizon here at 11 just as I was packing up.
Quote:
Originally Posted by AlexN
Ps. Look at all your background galaxies. Hundreds of them. That heavily red shifted lot to the left look interesting.
That's half the fun! Not sure what that little cluster is but it's one of the cooler features in the image (imo). When I did the RGB initially I rotated the camera too much and had to crop half of it out, but after doing the second run I was able to bring it back in.
I was about to say I kinda like it 
