NGC 5128 Centaurus A Galaxy

[Startrek (Martin)]

Finished capturing this image of NGC 5128 Centaurus A galaxy at 2.30am this morning
40 x 2 minute guided subs
15 x darks
ISO 400
Canon 600D unmodded
8” f5 newt on a EQ6-R mount
Stacked in DSS
Processed in Startools
Lots of issues with this image but cleaned it up as best I could
Colour needs to be balanced better
In hindsight I should have dithered my subs to minimise the noise
Still very happy with the new rig !!

[raymo]

Good job, but why 400? 800 is the sweet spot for the 600D.
raymo

[Outcast (Carlton)]

Nice Martin, great pic...

[Startrek (Martin)]

Thanks Raymo
Have you ever imaged in Sydney ( mega skyglow )
I took a 2.5 minute test exposure at ISO 800 and the RGB histogram curves ended up on the 2/3 line
The capture screen on BYEOS was like a white sheet
Dropped it down to ISO 400 and took a 2 minute test exposure , histogram curves ended up right on the 1/3 line and screen looked bright but within reason ( I knew Startools could wipe the gradients , vignetting and skyglow away )
You are spot on Raymo regarding the light gathering capability of the new 8” f5 compared to my old 6” f6 ( chalk and cheese )
I’m going to have to re think all my settings in the future for Sydney and at my dark site down the coast
Thanks

[Startrek (Martin)]

Thanks so much Carlton
Really enjoying AP and looking forward to a good year under the stars
Martin

[xelasnave]

Great image. Great to see you hitting the deck running☺
Alex

[Startrek (Martin)]

Thanks Alex
The new 8” f5 has exceeded my expectations
Can’t wait to chase after some dim galaxies down at my dark site
Martin

[Screwdriverone (Chris)]

Sounds like you need to buy my Canon EOS CLS Clip filter Martin

I used to use this ALL the time in Kellyville Ridge on the Canon EOS 1000D and it really cleaned up the skyglow and brought out the contrast.

Prior to using it, I took an image of a sunlit a4 piece of paper and set the custom white balance to that shot and then used the custom WB when taking astro photos, to eliminate the blue cast from the CLS filter.

Check it out on the accessories forum here

[End of Advertisement, lol]

Cheers

Chris

Originally Posted by Startrek

Thanks Raymo
Have you ever imaged in Sydney ( mega skyglow )
I took a 2.5 minute test exposure at ISO 800 and the RGB histogram curves ended up on the 2/3 line
The capture screen on BYEOS was like a white sheet
Dropped it down to ISO 400 and took a 2 minute test exposure , histogram curves ended up right on the 1/3 line and screen looked bright but within reason ( I knew Startools could wipe the gradients , vignetting and skyglow away )
You are spot on Raymo regarding the light gathering capability of the new 8” f5 compared to my old 6” f6 ( chalk and cheese )
I’m going to have to re think all my settings in the future for Sydney and at my dark site down the coast
Thanks

[Startrek (Martin)]

Thanks for the heads up Chris
I bought an EOS CLS filter 2 years ago but didn’t use it much
80% of my imaging is done down the south coast at my holiday house dark site
I’m only setting up the 8” in Sydney to give it a test run and then it’s permanently going down south
My old 6” f6 is staying in Sydney and works fine through all the sky glow ( captured some good images of Orion through the summer in Sydney
Cheers

[Camelopardalis (Dunk)]

Originally Posted by Startrek

Thanks Raymo
Have you ever imaged in Sydney ( mega skyglow )
I took a 2.5 minute test exposure at ISO 800 and the RGB histogram curves ended up on the 2/3 line
The capture screen on BYEOS was like a white sheet
Dropped it down to ISO 400 and took a 2 minute test exposure , histogram curves ended up right on the 1/3 line and screen looked bright but within reason ( I knew Startools could wipe the gradients , vignetting and skyglow away )
You are spot on Raymo regarding the light gathering capability of the new 8” f5 compared to my old 6” f6 ( chalk and cheese )
I’m going to have to re think all my settings in the future for Sydney and at my dark site down the coast
Thanks

Martin, the skyglow accumulates linearly with time, as does the thermal noise.

Couple to the read noise, which is worse at ISO400, and you're really better off at ISO800 as raymo says

The "bonus" at 800 is that you can get 2x the number of subs in the same length of time, and the random noise will be controlled better.

Nice image all the same

[raymo]

If you are referring to the histogram curves in DSS after stacking, it doesn't
matter where they are initially; the screen is often completely blank until
the curves are moved toward the left of the screen.
raymo

[Startrek (Martin)]

No, the histogram curves on my capture software BYEOS, theres a little graph in the top right corner which displays the histogram for each sub

On another note , when I stack in DSS I don’t alter anything after the stack as my processing software Startools requires linear data

[Startrek (Martin)]

Thanks Dunk
I was aware that ISO 800 is the ideal setting for my 600D
I guess the new 8” f5 newt caught me by surprise with its light gathering capability compared to my old 6”
Cheers

[assbutt94]

That's a fine result!
Your image has convinced me to maybe try recapture NGC 5128 without my CLS filter if I get the opportunity. The colours of your image are much nicer!

[Startrek (Martin)]

Thanks Nathan
You need at least 1.5 to 2 hours of data for this image as there’s a lot of hidden detail at magnitude 7
Startools has never let me down when processing either in light polluted Sydney or down the coast at my dark site, very intuitive and lots of great modules
No levels or curves to tweak , just drop your stacked “linear” image into it and the software does the rest
Cheers

[mynameiscd (Andy)]

Fantastic shot Martin!!!
You caught a fair amount of detail consider the LP.
Looks like I might have to invest with an 8" to keep up with these sort of quality images.
Cheers
Andy

[Startrek (Martin)]

Thanks Andy appreciate the kind comment
Took me 6 months to do the research and convince myself to step up to the 8” f5 and I’m glad I did.
The 8” f5 and the EQ6-R mount is a great combo,the mount carry’s the payload ( 13kg ) with ease and is whisper quiet compared to my HEQ5 which sounds like a meat grinder
The Baader coma corrector is brilliant, no more coma
The scope was only $455.
This is my AP rig for life !!!
Cheers