California Nebula

[Farooq]

The high summer humidity over here finally started improving, from a high in summer of 80% to 60% now in October and going down.

So after a 2-3 month lull I was able to get the kit out. I tried M31 again this year but absolutely no success, simply too much skyfog and light pollution, so I thought I would have a go at nebulae instead. 

Below is last weeks effort, 12 x 1200s Ha processed using PixInsight (am just learning this great bit of software).

I have just received a new set of OIII and SII filters and started getting some subs. 

A question for narrowband imagers, I was advised by another astrophotographer to binx2 the OIII as the signal is quite weak in this object and capture unbinned SII.

True enough, binx2 of the OIII at 1200s is bringing in a more stronger signal. However, the SII unbinned is not showing any nebulosity at all when stretching the image, even if I binx2 the exposures. I am unable to go for exposures longer than 1200s.

Can someone please advise...

[johnrt]

I think the SII signal in this object is very very weak, very dark skies and very long exposures will tease it out, but to us mere mortals it is beyond what we can capture.

I wonder why you have been advised to bin OIII but not SII, I can see no logic in this thinking at all, the Ha contains the detail and contrast, the OIII and SII in 99% of cases just provides a colour hue to the image and contains no details as such. There must be a reason, but I cannot think of one, I would bin both if you decide to go down that route. Personally I never bin any subs, and don't shoot longer than 1200 secs.

[Mark72]

nice data, you probably used deconvolution heavily or something similar, it leaves some artifacts in background.

Mark

[Farooq]

I think the SII signal in this object is very very weak, very dark skies and very long exposures will tease it out, but to us mere mortals it is beyond what we can capture.

I wonder why you have been advised to bin OIII but not SII, I can see no logic in this thinking at all, the Ha contains the detail and contrast, the OIII and SII in 99% of cases just provides a colour hue to the image and contains no details as such. There must be a reason, but I cannot think of one, I would bin both if you decide to go down that route. Personally I never bin any subs, and don't shoot longer than 1200 secs.

Thanks for the info John. I have tried binning the SII and the signal is hardly there. Unfortunately I do not have the luxury of very dark skies.

If I cannot get any usable amount of SII then i may have to synthesize one the HST channels from the other two.

I have never done any full NB imaging and processing before, so it should be an interesting experience trying to put an image together once I have sufficient subs.

[Quatermass]

Looks great to me 

[symesie04]

Looks pretty good to me as well.