Xmas in July - Horsehead

[Bolts_Tweed (Mark)]

Since working out the monitors and starting to use Pixinsight - I have spent the day revisiting old data to see what I missed (or what can be improved )

It has been a while since there was an inundation of Horseheads so I thought what the heck.

The flexibility of the masking function in PI allowed improvement to the reflection neb at the btm. I am a bit worried over the excessive blue halo just above his head. None of the other blue stars have a halo to this extent so I just dont know (but then again no other larger blue stars are in the red curtain I suppose). Background Neultralisation, DBE and ACDNR in PI were also a definate advantage in processing. The detail in the cloud edges to his right is also improved I think without the excessive addition of noise (well not too much anyway)

It's a Ha, R, G, B (120, 30, 30,30) with the AP130EDT and ST8300 with Astronomik 6nm Ha and Astrodon RGB.

Sry to revisit but thought i'd show the differences in processing tools.

Mark Bolton

[TrevorW]

Nice Horsey Mark it sort of just, hard to describe but well done on the reprocess

[gregbradley]

Nice repro. One way to reduce the blue halo is to use the sponge tool set to desaturate and 50% and rub on the areas you want to reduce the colour of.

Similarly the core star area of the blue reflection neb is a bit overblown so shadows/highlights lassoed to that area only or curves to get the core data back.

Overall a very nice image. That is the max you will get out of that without more exposure time which is too little (120 30 30 30 is not enough for the Horeshead - maybe 4 X that to get it really smooth).

Also shooting luminance is best done with no filter or a clear filter.

Greg.

[multiweb (Marc)]

Wow! Very nice indeed. Very sharp details and defined outlines.

[luigi]

Terrific!
How are you liking pixinsight? Maybe you find some time to open another thread and comment about it?

[Hagar (Doug)]

This has come up very nice Mark. I have Pixinsight but have yet to spend much time on this software yet. It does seem dificult compared to PShop but then I am used to PShop.

[Bolts_Tweed (Mark)]

Thx guys

Yeah Greg - this was a yahoo i've got my AP image when Orion was getting low - i agree more data. I only seem to get the curtain effect in Ha but - For some reason I only get a flat sheet of nebulosity with Astrodon Lum filter. I am still struggling with this filter as my star 1/2FDs are usually of the order of 60% larger than those I get in RGB - even with reduced exposure substantially - I still cant work it out - that is why I am imaging Ha blended Lums. I am hoping to catch Don GOldmans ear at AIC to query him on it - it is obviously something I am doing wrong. Hint taken re the sponge mate - will try it.

Thx Marc

Gday Luigi - I am happy to discuss PI but I am in no way an expert. Houghy from this forum is far more adept than I am - but if you start another thread then I will keep an eye out (maybe in software) and throw in my 2cents.

Thanks Doug - I have found the PI leap is a leap of faith. Harry Page's page (and Houghys) is a great help but the documentation is pretty light. Rogelio Andreo also has some good stuff - especially regarding masked stretches and star masks. I still fall back on CS3 but when I am lost in PI - old habits die hard. But by comparison to my first version of this image it shows a marked improvement.

Mark Bolton

[gregbradley]

[
Yeah Greg - this was a yahoo i've got my AP image when Orion was getting low - i agree more data. I only seem to get the curtain effect in Ha but - For some reason I only get a flat sheet of nebulosity with Astrodon Lum filter. I am still struggling with this filter as my star 1/2FDs are usually of the order of 60% larger than those I get in RGB - even with reduced exposure substantially - I still cant work it out - that is why I am imaging Ha blended Lums. I am hoping to catch Don GOldmans ear at AIC to query him on it - it is obviously something I am doing wrong. Hint taken re the sponge mate - will try it.


I am not sure 100% what you are saying here. 1/2FDs? what does that stand for 1/2 full well depth of the CCD?

The 8300 chip has small well depth of about 25,000 electrons. This is a low number. For example the 16803 chip has about 100,000. What this means as far as practical application is bright stars spill over and become bloated quite easily.

Is your luminance filter UV/IR coated or is it a clear filter (with no UV/IR block). A clear filter will bloat stars more than a luminance filter (UV/IR coated) but it lets more light through and gets a bit more of the really faint stuff. But that is the cost.

Are you focusing on the luminance filter sharply? It sounds odd the stars are 60% larger than in the colour filters. Usually blue has the largest stars sizes.

Greg.

[TheAstroGuy (Shane Ross)]

Beautiful Shot!!

So good to see the Horse out of season , the Curtain of Hydrogen A is really well defined, Lovely work !!

Kind Regards

Shane

[Bolts_Tweed (Mark)]

Yeah thanks Shane. I remember years ago being happy seeing a faint horsehead - now we are chasing detail in the curtain - how things change. A professional astronomer friend tells me that this streaming curtain is caused by the magnetic field of the galaxy as it spins - quite incredible really.

Mark

[TheAstroGuy (Shane Ross)]

Yeah that is really cool, kind of like a Nebula Aurora!