M83 RGB + Ha

[ozstronomer (Geoff)]

First galaxy with the CCD camera and Ha added

W.O FLT110 with G2-8300 Moravion camera
40min each RGB and 60 min Ha
Nebulosity and CS3

I'm not sure about the colour mix, comments and suggestions welcome

[allan gould]

Must have left the dust cover on. Can't see nuthin!

[renormalised (Carl)]

Don't bother with the Ha filter unless you're going to use it for luminance. Unless the galaxy has a lot of prominent HII regions it wont do much. You can get away with using a simple clear UV/IR block filter for your luminance.

Oh, and post your piccie!!!!.

[renormalised (Carl)]

Originally Posted by allan gould

Must have left the dust cover on. Can't see nuthin!

Diligently taking darks

[Mighty_oz (Marcus)]

If u post an image we can all get to see your results I surely would like 2

[ozstronomer (Geoff)]

Now with correct size image

Thanks for looking

[Bassnut (Fred)]

mmm, your not going deep enough there. As Carl says, Ha is not the go with galaxys, you should have spent the Ha time on Lum.

[renormalised (Carl)]

Luckily, Geoff, M83 has quite a lot of HII in the arms so you'll get some response with a Ha filter, but in order to really do it justice you need to boost the F ratio. A galaxy like M83 needs image scale to show it off.

[RobF (Rob)]

C'mon guys, this is only about the 2nd or 3rd target Geoff has tackled with the CCD camera I think. Now Ha is in the arsenal you can't blame him for having a go, particularly from Brissy skies. Its a whole new ball game getting a feel for binning, Lum and RGB ratios.

I'm sure you'll get more of the arms to come out in future efforts too Geoff, and I was actually interested to see what the Ha did for you. I have to confess this is one of the first things I tried on a galaxy when I got the QHY9, and my effort was a lot less successful to be honest (I think it was 6744 which in hindsight was never going to be useful)

I guess there aren't too many M33 style galaxies that really shine with a bit of Ha added in, especially if you haven't already got quite a few hours of Lum data under your belt.

[allan gould]

Geoff
Good attempt at M83. But it looks a little too over processed in that you have lost star colour and too much colour in the galaxy. I'm a fine one to talk but getting the data is only half the battle, your tracking focus etc are all ok but it's in the processing that the real results are brought forward. Like some have pointed out reserve the Ha for nebula etc that have Ha emissions as galaxies generally are not in this arena. Just keep on getting your luminance data and the rest will eventually fall into place. Your learning curve is very steep at the moment but keep at it. Image the bright stuff first then go for the harder targets.
Allan

[Tandum (Robin)]

Geoff,
I recon adding Ha to M83 is ok and as per my attachment it does give off Ha and it looks like it shows up nebula in that galaxy. I would suggest mixing it with the R and L channels. Also you need to go deeper on galaxies, 10minute subs and 15 or 20minutes for Ha.

[Hagar (Doug)]

Great attempt Geoff. Don't get to carried away with Ha blending. It really is another mine field for you to get into. For galaxies the general rule is not to bother using Ha as a blend with the luminance layer but maybe blend a small amount into the red channel but even then only just a little.
M83 is a great galaxy to image as it's size allows very good resolving in even quite short focal length scopes and given sufficient exposure you will capture the red HII areas quite well without the Ha.
The real art in capturing detail in Galaxies lies in focus and then the big one, EXPOSURE and lots of it. Get a good Luminance layer and some nice RGB and you will have a Galaxy to hang in the pool room.

I don't think anyone was having a go at you about the image or Ha but more just trying in their own way to warn you off Ha in galaxies.
Your imaging is progressing very well but don't jump to quick into Ha blending. Enjoy Ha in it's raw form as black and white when the moon is high etc. and get as much good RGB data as you can and really get comfortable processing LRGB first before venturing into Ha blending.

Keep at it.

I've added an image of M83 I took a month or two back. This is a crop of a full image taken with a 106mm Scope at 530mm FL with no Ha added at all just lots of LRGB about 4 hours in total and half of that was luminance.

[ozstronomer (Geoff)]

Hey Guys, really happy to get the feedback, that's how we learn, so keep it coming.

It is quite a learning curve this CCD imaging but having lots of fun.

I'll go hard on the subs/exposure time next outing and see how that goes

Thanks for the help

Cheers