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Comparing Data - Thor's Helmet


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Due to the perpetual bad weather, my imaging time has been reduced to a couple days a month.  So it takes me a very long time to finish an image.  This afforded me with the opportunity to compare image taken of the same target with a single scope setup vs multiple setups (with .6x reducer)....the very long form of binning the color and not binning the lum.  For the first of these images, I used the OIII data collected from a couple of years ago with the FSQ 106 and .6x reducer and the Ha collected with the FSQ 106 native (without reducer).  I registered the wide field data with the native FOV and am quite pleased with the results--though star size suffers.  Also, the scope needs to be realigned/collimated or otherwise "fixed" - which tends to hurt the data at the faster F3 configuration than at the native F5.  So, not ideal, but it was all I could do.   I am currently collecting new OIII data with the FSQ without reducer to be paired with the newly captured Ha data with the same setup.  One more clear night should do it.  Mean while--here is the image that includes 85 300 sec Ha subs collected at 530 mm FL and 130 300 sec OIII subs collected at 318 mm FL.  Second image to follow when it is completed in a week or so.  No doubt this post will be off the first page by then--but I will resurrect it as opposed to creating a new one.  It will be interesting to see if resolution improves.  I did have a bit of trouble due to differing signal strengths--the F3 OIII data was even stronger than the Ha as is typical for this target.

Image #1--Ha FSQ Native/OIII FSQ reduced.  I originally had the image a bit brighter, revealing moiré background Ha and surrounding OIII emissions, but my sky makes for very difficult backgrounds, requiring lots of noise suppression or a gentle stretch.  The more I look at this slightly less bright version, the more I like it (though the extensions are not as full)

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A midway point - I collected 3 hours of new OIII.  Not enough for as clean an image as I would like--but I think much improved.  seems more balanced, softer, with much better stars.  3 more hours should do it.  Then, I really need to think about collecting more Ha during a night of really good seeing.

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14 hours ago, Rodd said:

Here's a crop so you don't have to bother clicking

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Nice detail in the crop Rodd and certainly the stars are better.   Could you post the Oiii and Ha data for a look, dont often see strong Oiii signal!

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Very nice Rodd, I don't often get to a location to be able to do this, but when I did I found it a bit tricky to process.  Maybe I just didn't have enough data.

Carole 

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8 minutes ago, carastro said:

Very nice Rodd, I don't often get to a location to be able to do this, but when I did I found it a bit tricky to process.  Maybe I just didn't have enough data.

Carole 

Thanks Carole. For me its tricky because it is so low in a very LP rich section of my sky.  That and bicolor images always give me a bit of trouble. 

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16 minutes ago, tooth_dr said:

Nice detail in the crop Rodd and certainly the stars are better.   Could you post the Oiii and Ha data for a look, dont often see strong Oiii signal!

Thanks, Doc.  Yes, this is a rare target where OIII is much stronger than Ha.  I intend to collect another 3 hours or so of OIII tonight to finish the image.  I will post the new image and the Ha and OIII masters when I am done.

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From Home where I am Bortle 8 it is below the tree line.

From Astro camp it is Bortle 4 but as you say very low from the UK.

Carole 

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That is a great image Rodd, nice detail and I especially like the second version with more neutral (not all cyan) star colours. It reminds me when I one processed Thor data that there is a lot of Ha there, really a lot, that surrounds the Oiii. I once maybe got over the top to prove it:

https://www.astrobin.com/385247/C/

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This is without doubt the best image ever taken of this target and is probably in the top ten of any astro images ever taken.

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On 09/03/2021 at 15:45, gorann said:

That is a great image Rodd, nice detail and I especially like the second version with more neutral (not all cyan) star colours. It reminds me when I one processed Thor data that there is a lot of Ha there, really a lot, that surrounds the Oiii. I once maybe got over the top to prove it:

https://www.astrobin.com/385247/C/

Thanks Goran--yes--there is a lot there.  But it seems strange that it does not really appear in the nebula itself despite the Ha stack being bright throughout the nebula.  It sows up on the fringes.  

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As promised--here is the final image with a full data set 85 Ha and 73 OIII--13.2 hours.  If I doubled everything and only used  subs from a good seeing night, I am sure it would be improved.  But this is it for me.  The difference here is one of sharpness throughout, really.  It is subtle, but the details on the wings is sharper--and the helmet too.  Also the extensions are more prominent and more transparent tried to keep the background/stars/palette the same as I like them.  Note, these are not Ha stars--but colored stars, almost like RGB stars, which is not typically how I portray narrowband stars as the colors usually are too plastic for my liking.  But in this case, that is not so.  No crop this time as most don't prefer it

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