M13 lacking colour

[Andrew-77]

Hi all. This is only my fourth or fifth attempt at a DSO and the first time I've had the scope out this year. I had a crack at M13 last night but I don't seem to be able to get any colour out; I ended up with a very monochrome image. I was pleased with the amount of stars in the cluster, but disappointed at the lack of colour.

Also, the circular bands you can see, any ideas? I've toned them down as far as possible using levels and curves in P'shop but they were very pronounced at first.

227 x 20sec subs at ISO 800

Stacked in DSS

I did a few smaller stacks of 50 frames and they seemed more willing to give some colour.

[nephilim]

Ive no experience to comment on the 'bands' although it could be lp, regardless of that its a really good image of my favorite globular.

Steve

[Andrew-77]

Thanks. I notice from your sig that we have very similar setups, what's the longest sub you've managed with the dual motors? When I took that image I'd (probably more by luck than judgement) managed to achieve almost perfect polar alignment. I wish I'd pushed it a bit and got either more or longer subs.

[Mark72]

Did you use flats?

May be you can post unstreched tiff file?

Mark

[Daniel-K]

Its a stacking issue in dss I had the same. I think you need to use bilinear its one of thosesettings in the lights tab. Also your secondary isnt squaret under your focuser thats why you have the dark patch on the left. As for colour when saving in dss make sure you save with settings applied and give it a saturation boost and more data

[nephilim]

Thanks. I notice from your sig that we have very similar setups, what's the longest sub you've managed with the dual motors? When I took that image I'd (probably more by luck than judgement) managed to achieve almost perfect polar alignment. I wish I'd pushed it a bit and got either more or longer subs.

Sorry mate, only just realised your reply, I'm only starting out & struggling sorting out irritating IT problems with my 350D 'talking' to byos so i've had no attempts at all so far. I think you've done a great job considering your starting out aswell.

Steve

[andyo]

Yes other than the banding thats a very nice glob well done

[Ewan]

Its a stacking issue in dss I had the same. I think you need to use bilinear its one of thosesettings in the lights tab. Also your secondary isnt squaret under your focuser thats why you have the dark patch on the left. As for colour when saving in dss make sure you save with settings applied and give it a saturation boost and more data

Daniel as i understood DSS it's best to save the stacked image using the Embedded option & not the Applied option as it's best to use either Pix or PS to do all the processing. I also save in 32Bit mode before dropping in PS, in 32Bit mode PS won't display the RGB seperate channel peaks but you can still make the channel adjustments, if you need to see the peaks (on the right hand panes) then load into PS & goto Image - Mode - 16 bits/Channel & save that.

In DSS i have not had to increase the Saturation option in the processing section to get colour, i just stack & save, the colours will show in any editing software.

Feel free to pm me Andrew.

The banding maybe an artifact just from processing but i am not sure exactly what causes this to happen.

PS, Andrew was there by any chance a full or partial moon near this when you took it ? that can also cause the image to appear darker on one side than the other.

[Gina]

Nice one