Narrow Band imaging help

[Bigfoot 9907]

Hi all,

I am now at a stage where I am thinking about Narrow Band imaging. but I am still a complete novice.  I have been given a UHC filter and took 6, 600 second stubs along with calibration frames of the bubble nebulae, just to see the type of image I would get.

However, when I stack the images, using DSS the resulting image is extremely noisy. I am sure i am doing something wrong.The light and calibration frames can be found here.

https://drive.google.com/folderview?id=0B-Afq_Dv8HerRVRkVmdIWWgwQk0&usp=sharing

Can someone please have a look and point me in the right direction. I assume that the stacking in DSS is the same for Narrow band images as it is for color.

Many Thanks

Surinder

[Davey-T]

Not sure how narrow band a UHC filter is, 6 subs isn't enough to get a good signal to noise ratio.

Dave

[swag72]

Narrowband is generally referring to Ha, OIII and SII - As Dave says, I'm not sure that the UHC would be considered NB.

6 subs and I presume with the moon around is going to give you some noise issues for sure. 6 subs isn't an awful lot and the moon is a noise causing monster. The Ha filter is the best one to use during a large moon period, but even then, that will give you issues. 

While the moon is about, use the time for testing and sitting on the sofa moaning about the thing :d 

[geordie85]

The first time I tried narrowband imaging in Ha I only had 6 subs of 10 mins thinking it's an hours worth of subs, it'll be fine but it wasn't and it was drowning in noise.

I then continued to collect data and ended up with 5 hours worth of subs (30) and when I stacked them I noticed that there was alot less noise.

So the moral of the story is more subs will produce less noise.

I hope this helps

[Bigfoot 9907]

Thank you gents  . I had planned to take more stubs but,  a breeze would appear now and then causing a ruinous spike on the PHD graph. A few stubs were ruined and had to be discarded.  A SW 200p sitting on a HEQ5 mount is like a sail in the wind