First go at a DSO

[Dann]

Last nights lovely clear sky gave me the time to have a go at my very first DSO, good old M13.

I'm looking to get guiding at the end of the year but for now I've set myself a '30 second' challenge to see what results I can get with unguided 30 second exposures.

This is a stack of 103 x 30sec

30 darks

30 flats

and bias

I'm not sure the flats have worked properly mind, there seems to be some kind of blueish gradient on the right hand side although I'm pretty pleased for a first attempt.

Thank you also for all of the help and advise.

Thanks

Danny

[Dave Smith]

That's pretty fantastic for a first go. Nicely focused.

Dave

[BlueAstra]

Excellent image! Have a look at 'Gradient Exterminator' as a fairly inexpensive way of removing gradients, or look up various PS methods if you have PS.

[foundaplanet]

Nice one Dann...

[RikM]

Very nicely done, well resolved core. Try increasing the saturation to get a bit more colour into it. With 100+ subs you should have plenty of data there to pull out. I have found twith my own images hat being too agressive on the top end of the curves adjustment washes a lot of the colour out. Either more work with levels at the start or pinning a bright star in curves before stretching has helped me. Keep it up, you're on the right track.

[Dann]

Thanks for the feedback guys, ill take a look at Gradient Exterminator as suggested.

I found when I tried to boost the saturation after stretching the core started to become one big ball of white. Maybe masking the centre before doing it would help?

[RikM]

I just had a little play with the jpg and I couldn't bring any more star colour out either. This was a problem I used to have, but I have found lately that really looking after the highlights so you don't over-stretch them to become pure white helps to retain the colour information.

That said, you have still produced a very fine image for a first.

[mark7331]

Very nice shot and you've even managed to bag the galaxy NGC6207 (unless I'm mistaken).

I'm not sure that your flats have worked either as you appear to have some vignetting and although it can be removed easily enough with software better flats or processing of the flats should take care of it. Also I don't bother with the bias frames as the bias signal is already in the darks.

I had a quick play in PixInsight and the vignetting comes out really easily so, as has been said, Gradient Exterminator will do the job.

I like this a lot - really nice shot Danny.

Mark

[RikM]

Also I don't bother with the bias frames as the bias signal is already in the darks.

If you use DSS to stack, you need the separate bias frames as well to properly callibrate the flats. It doesn't work the same way as Maxim DL. If you don't include flats, DSS subtracts the bias signal along with the darks as you would expect, but if you use flats it can't take the bias info from the darks and apply it to the flats, it needs the bias info separately.

[Dann]

Thanks for clearing that up Rik, I was a bit confused regarding Bias up until a few weeks ago, probably just because of the different programs we all use.

If I load flats and not bias into DSS then I'm warned about it.