Helix 6 hour exposure

[Gavin1234]

Hi, so I’ve been playing around with my new gear gathering a lot of data.

I took 327 x 30 second exposures before I got my guide scope and 43 x 5 min exposures after. I stacked the 30 second exposures along with about 240 bias, 45 darks and 45 flats in one group and the 5 min exposures with no calibration frames in another group.

Obviously I’ve done a lot wrong because my 20 minute image looks better than this one which is over 6 hours of data. There’s a whole heap of noise and I think dust motes? Also I think the top right quarter is light pollution?

Any ideas as to where I’ve gone wrong? Happy to post the original stacked image (before I butchered it �� ) in case anyone’s willing to take a look at for me.

[barx1963]

I am guessing you need to calibrate your 5 minute subs. 43 x 5min should give you a decent result if properly calibrated. At very least use flats to get rid of the dust motes. What processing program are you using?

Malcolm

[Cimitar]

You might be right, the gradient in the top right hand corner could be light pollution. Of all the calibration frames, I find flats are the most worthwhile. They're great for dust motes and also for removing gradients in the image. I also use dithering because it helps with noise in my DSLR. I dither every sub and find it helps enormously.

You mentioned "posting the original stack, in case anyone’s willing to take a look". I had a crack at processing the image included in your original post, however, I will only upload it if you're happy for me to do so.
Re-processing other peoples images is generally frowned upon, unless the person specifically asks. :thumbsup:

43 x 5min should definitely get you good results. You're stars are looking great, nice and round. The focus appears good too, as far as I can tell :)

Cheers,
Evan

[netwolf]

Pixinsight could remove the LP gradient, but if you dont have it try fitsworks. I believe fitsworks has some background neutralisation routines.

Glad to see your catching the light.

[Gavin1234]

Thanks guys, I will definitely do some calibration frames for the 5 min subs. I’m using photoshop for processing at the moment but I have requested a trial version of PixInsight. Apparently they manually approve each request so not sure how long that takes.

I think one of my kids has turned on the kitchen light while I was taking some of the subs. My scope is right outside the kitchen window. Seems like it’s too much to ask for people to cook dinner in complete darkness while I’m taking photos :lol:

Evan please go ahead and post it. I’m only posting these works in progress to learn from people here anyway so I’m hoping to see how I can improve them. I’ve also posted the stack of 352 x 30 sec subs and the stack of 43x 5 min subs before I learned you could stack them all together. The one with the mostly darker/blue background and the LP confined to the right hand top corner is the 30 sec subs.

Thanks again for the help.

[rcheshire]

Hi Gavin. Is this an 80D or ASC image? In any case, calibrate all the frames.

The stack is very closely aligned and this can work against you. As mentioned, dithering will assist in dealing with random noise, image flatness and a raft of other artefacts.

Put a blanket over the kitchen window:)

[Cimitar]

Hi Gavin - image attached as discussed.
This was a reprocess of your image at the top of this thread.

Cheers, Evan

[xelasnave]

Nice one Gavin.
Pull it out and do a reprocess a couple of months from now has been my approach ...don't be like me who trashed a lot of data from my restart I would love to have a reprocess of stuff I took a year ago and see if they are any better.
alex

[Gavin1234]

Thanks Evan, what did you use to get rid of the light pollution? Pixinsight?

Rowland it was taken with an ASI071MC not sure if that’s what you meant.

Thanks Alex yeah I’m being careful to label and save everything.

[Lee]

I think it’s great, I was in Sydney on the weekend, looking up I think all I could see were the planets, I don’t know how you do it...

Keep all your data, I just dug out some of mine from 2005 last night, nothing worth processing but nice to reminisce....

[Cimitar]

Hi Gavin, apologies for my late reply.
I used GradientXTerminator, it's a plug-in for Photoshop.

Cheers,
Evan