Caldwell 4 - The Iris Nebula (Moon 99.9% full)

[JohnH]

Clearly, the first rule of imaging the Iris Nebula at full moon is - DON'T IMAGE THE IRIS NEBULA AT FULL MOON!

This was:

L - 240 x 20 secs
R, G and B - 80 x 45 secs.

Sharpstar 15028HNT, iOptron CEM25P.
Processed in Pixinsight.

I have really thrown the Pixinsight equivalent of the kitchen sink at this image which was not helped by messing up my Flats.

At least I have managed to image something which is not red.

Regards,

John

[Carole]

Very brave to image this from Bromley John, let alone a full Moon. 
You have such different equipment to me, and use different processing software, I can't give you any suggestions to help, but it is not bad as it is.

Just curious why you did longer subs on the RGB than the luminance, I would have done longer on Luminance than RGB as that is where all the detail lies. 

Well done

Carole

[JohnH]

Just curious why you did longer subs on the RGB than the luminance, I would have done longer on Luminance than RGB as that is where all the detail lies. 

The real answer to that is inexperience . I was trying to reduce noise in the Chrominance layer but I suppose I should really have concentrated on Luminance. My thought was that this target would have no significant Ha which is my preferred filter for detail.

I was having a real problem with dew (frost!) on my Guidescope. I have a dew heater, but possibly not in the correct place, I will make a dew shield as well. BTW, should the dew band feel warm? - I cannot detect any difference between mine and the ambient.

Regards,

John

[Carole]

Only feels slightly warm and sometimes l have to have my hand on it fir a few seconds before l can feel the warmth.

[Roberto]

That is a very good result for the conditions John.  You have got the colour spot on for the central part of the nebula and it is not blown out which is difficult to achieve.  Your background may be a bit clipped though and I think there's signal there that is going to waste.  Do you have an unprocessed master frame you could share in .xisf format?

I think I could do a PixInsight processing session for some members if that is of interest.

Roberto

[Carole]

format?

I think I could do a PixInsight processing session for some members if that is of interest.

Roberto

We should set up a session for those who are interested. 

Carole

[JohnH]

Hi Roberto,

Thanks. I confess the colour is down to a massive saturation boost in the blue channel with a mask in place. I had to cheat when processing because I found that I had mucked up my flat fields.

I am not sure whether this will work but this is a link to a copy of the Luminance Master in XISF format (I cannot think of any other way to share an XISF file) :

https://www.dropbox.com/s/6t6ppf2nvl2lk96/masterLight_BIN-1_4656x3520_EXPOSURE-20.00s_FILTER-L_mono_autocrop.xisf?dl=0

A Pixinsight "Masterclass" would be very useful and, I am sure, very popular.

Regards,

John