M8 with a CLS-CCD filter - reprocessed

[rcheshire (Rowland)]

I'm not ready for the big boys forum, so here is M8 reworked... it needs more data, flats etc... I think it has become a little saturated, but I didn't clip the BP this time - I did check that.

More data is needed, but the filter works and there is considerably more signal over an hour compared to 2 hours without.

Those little red wavelets (to give them a name) throughout - not sure what that is... but I think, more nebula breaking through?

updated version

[NorthernLight (Max)]

Hi Rowland,

very nice shot!

was that taken with the 1000D w/ eos clip filter and the ed80?
how many subs did you take? were they all with filter or some without?
did they come out bluish? how did you got rid of it?

btw: I get the same wavelets on this object, so either its an SLR thing or they are real.

till then!

[multiweb (Marc)]

Originally Posted by rcheshire

I'm not ready for the big boys forum, so here is M8 reworked... it needs more data, flats etc... I think it has become a little saturated, but I didn't clip the BP this time - I did check that.

More data is needed, but the filter works and there is considerably more signal over an hour compared to 2 hours without.

Those little red wavelets (to give them a name) throughout - not sure what that is... but I think, more nebula breaking through?

...here...

It is really a very good picture. You just need to do a couple of very simple processing steps to make it 100%. Your green chanel is perfect. Your blue channel is white clipped. Load it in PS and check your stars. They're punched in the middle. Could be a number of reasons. You use a small aperture scope and your subs were too short or you pushed the saturation too high. That's an easy fix though by doing a star mask and using a median filter to spread the luminosity back into the core. Your red channel is the only source of noise in your shot. Again if you do one pass of noise reduction in the red you'll improve this shot ten folds.

[rcheshire (Rowland)]

Thanks Marc. I think this has fixed it, although I think the problem with the stars is partly optics/focus - not so bad this time round. I was careful with all black and white point clipping.

was that taken with the 1000D w/ eos clip filter and the ed80?

Hi Max - it was

how many subs did you take? were they all with filter or some without?
did they come out bluish? how did you got rid of it?

11 subs between 3 and 4 minutes each, all with the filter.

They were bluish. In Pixinsight, I calibrated the colour and neutralised the background. To recover the colour and luminosity I did a LRGBCombination on the luminance channel. I don't know how to do that in PS.

...here...

[multiweb (Marc)]

Originally Posted by rcheshire

Thanks Hi Max - it was
11 subs between 3 and 4 minutes each, all with the filter.

There lies you problem ED80 + 3-4min subs. It's a small aperture scope. Blue will not focus at the same spot as red and green. So you get less blues in your stars core because they're more of a donut shape than the other two channels. You'll find that if you push your subs time right up well over 5min you won't have this problem anymore.

[rcheshire (Rowland)]

Thanks Marc - very much appreciated. I'll try 6 - 7 mins.

Max - I'd be interested to see the results of processing with the CLS filter.

Cheers,

Rowland.

[NorthernLight (Max)]

Hi Rowland,

yes, me too-as soon as the rain has stopped. Next year or so.
I tried 2x yesterday and had to run fast on both occasions to rescue my gear from the rain. Now I am going to to wait until the moon is gone and hope for better weather around this time.
I´ll post the news here as soon as I have new data.
Cheers!

[rcheshire (Rowland)]

...and lots more expected...