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California nebula DSLR HaRGB

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#1 mackiedlm

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Posted 21 January 2020 - 03:24 AM

At last a couple of clear nights so tried the California nebula - first time imaging this.

 

The HA was done on the second night and the seeing/clarity was much worse than the first night so I dont think its as good as it could be

 

Only my second attempt at HaRGB and still learning

 

Anyway

EOS 1100d (Ha Mod)

Super Takumar 200mm f4
Skywatcher Star Adventurer
RGB 61 X 180s ISO 1600
Ha (astronomik 12nm clip in) 50 X 210s ISO 1600
Around 40 darks, flats and dark flats for each session
Stacked in APP processed in Photoshop

 

California_r6 flat j.jpg

 

Full res image here

https://astrob.in/vwmicw/0/

 

 


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#2 mxpwr

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Posted 21 January 2020 - 03:31 AM

I think it's quite nice.
It looks like you have some systematic tracking error, the stars are elongated upwards.

#3 Teddythefinger

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Posted 21 January 2020 - 05:19 AM

Uh that's awesome. I notice nothing.
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#4 the Elf

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Posted 21 January 2020 - 06:15 AM

Indeed, the stars are out of focus and elongated. The super takumar does not come to focus in Ha due to the infinity stop of the focus ring. I removed the ring and pushed the end bumper a bit further so that I have good focus for Ha now. No special tools required, just a small screwdriver. In this video you can see how to get access to it:

https://www.youtube....h?v=uA5GW-ba3Jc

 

It works well now for Ha but it has some serious longitudinal CA without filter. Some effort in post processing can mostly fix it. 

The elongated star problem can hardly be solved on a tracker. Only little deviation in polar alignment will cause drift. For the DSLR you use I'd rather try ISO800. You have a very limited dynamic range at high iso and your image has no star color. All stars are blown out. At lower ISO it will be better. 

 

For the equipment that you have it is a good shot but you probably reached the limit now. If you want to go deeper in it, resist the temptation to get the infamous AVX, go for a sturdy mount in the 1.5k$ range. I use the takumar on my EQ6-R as well as telescopes. Here you can compare your image to my version of the California Nebula, also taken with Canon DSLRs and Ha-RGB combination as you do. I call it Ha-OSC, though.

 

http://elf-of-lothlo...ornia2019.html 

 

There are plenty of imperfections in this image as well, but you can probably see the difference in star shape and size. This is what mxpwr is pointing out.



#5 mic1970

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Posted 21 January 2020 - 09:28 AM

Very nice.

At last a couple of clear nights so tried the California nebula - first time imaging this.

 

The HA was done on the second night and the seeing/clarity was much worse than the first night so I dont think its as good as it could be

 

Only my second attempt at HaRGB and still learning

 

Anyway

EOS 1100d (Ha Mod)

Super Takumar 200mm f4
Skywatcher Star Adventurer
RGB 61 X 180s ISO 1600
Ha (astronomik 12nm clip in) 50 X 210s ISO 1600
Around 40 darks, flats and dark flats for each session
Stacked in APP processed in Photoshop

 

attachicon.gifCalifornia_r6 flat j.jpg

 

Full res image here

https://astrob.in/vwmicw/0/


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#6 sunnyday

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Posted 21 January 2020 - 09:30 AM

nice


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#7 Starman27

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Posted 21 January 2020 - 11:23 AM

I like it!


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