Centaurus A LRGB

[peter_4059]

Spent both nights this weekend on imaging Centaurus A using the DSI II pro and 10" f5 Newt. Despite a few computer and guiding problems I captured 50x1min each RGB on Friday night and 100x1min L last night.

Still a lot to learn about how to process these images but I'm quite pleased with the result. Comments, criticism or advice all welcome!

Peter

[desler]

That's one very nice image Peter. Well done!


Darren

[AlexN]

Very nice Peter, and Talk about dedication... processing 250 subs must have been fun! :)

You'll likey get a pm from me in the not too distant future regarding combining LRGB images.... I have some goodies on the way!! he he he he heee!

Good image mate..
Alex.

[troypiggo]

Pete! Excellent results! That's one fine image, particularly from a light polluted city with the moon and computer problems all thrown in the mix. Ripper.

[peter_4059]

Thanks Darren, Alex and Troy.

Feels like it's all starting to come together now after quite a long steep learning curve. I'm realising how much there is to learn about post processing after focusing a lot on becoming efficient capturing. I still need to work out how to get the camera angle repeatable as this is causing unnecessary grief when I come to stack.

Alex - here's the LRGB approach I've been using.

http://www.tpo.ca/PS_Tricks/Steve_Cannistra_LLRGB.htm

Peter

[kinetic]

Peter,

what a beautiful job!
Absolutely well done.
It's such a pleasure looking at other's DS stuff but even more
so when it's a DSI II. The image scale is so familiar now to me :)


My camera is securely locked in place and hardly ever moves.
This way it is repeatable the next night I image and diffraction
spikes etc all should line up. Doesn't even move when I dial in a filter
change.
That is...until I move the OTA in it's bracket or something stupid
happens in the dark...like I bump the DSI and it spins! :)

Steve

[Octane]

Peter,

Wow! That's one of the nicest DSI images I've seen. So smooth! But, then, again, with 250 sub-exposures, you'd expect nothing less.

Looking forward to more.

Regards,
Humayun

[peter_4059]

Thanks Steve.

There's a growing group of DSI II imagers here and it's pleasing to see some reasonable results from the camera.

I suspect you are permanently setup so can afford to leave the camera on the focuser whereas I have a "Silver Tarp" observatory so am constantly removing the camera from the scope. I'm thinking of cutting a notch in the focuser draw tube and fixing a small grub screw in the nose piece adaptor on the camera so it always inserts in the same orientation.

I'm sure others have encountered and solved this problem already so hopefully they speak up.

Peter

[peter_4059]

Thanks Humayun,

It's been quite a bit of computer time to bring it all together. Hopefully the conditions here in Brisbane will be more favorable than they have been over the past few months. Hoping for a big imaging night next weekend.

Peter

Peter

[Alchemy]

some lovely detail in the dust lanes, you should be pleased with that one.

[peter_4059]

Thanks Clive - I'm pleased with how the dust lane turned out however the stars look a bit soft to me. I think there is a slight bit of misalignment due to the different angles I had to to deal with. I removed the camera over night and had a meridian flip during the RGB session.

Peter

[kinetic]

Another suggestion Peter,
I always hand (manually) align my stack in Neb, whether it's
50 images or 300. I never let it auto-align.
Things can throw it off and it's so quick you can miss a mistake
while in auto. It can lock on to another star or hot pixel and then
lock back on to the correct one for 299 of the 300 lights.
This will reveal itself as blurry stars in the result (but only if there
are lots of auto align mistakes).

FWIW.

Steve

[multiweb]

Wow! Very nice indeed. Nice details in the dust lanes. Cool pic :thumbsup:

[allan gould]

Very nice and smooth, Peter. You are getting to grips with this whole imaging think at a great pace and making great images.
Allan

[peter_4059]

Cheers Steve, Marc and Allan.

Steve,
I also manually align in Nebulosity however for RGB I haven't worked out how to get it to align the individual channels without also combining them so I do each channel separately and then manually align in PS.

[Alchemy]

snip.

you can run the image through a couple of iterations of deconvolution it will tighten them up.... not too many though, give it a try and see, just crop a small section and test with different psf's and iterations.

[peter_4059]

Thanks for the tip Clive. Here it is with a couple of passes through deconvolution.

[troypiggo]

Oh yeah, that certainly is sharper. Very nice!

[kinetic]

Stands up well to the ten foot test as well Peter ! :)

Steve

[peter_4059]

Thanks guys - what's the 10 foot test?

[kinetic]

Wow , your memory is slipping...:)

turn the lights out and look at it from 10ft away...

Simply awesome

Steve

[troypiggo]

Most of my images look good under the 50ft and squint your eyes test....

[allan gould]

Five guys telling you what to do?

[peter_4059]

yep - those brain cells are long gone. :drink:

[gregbradley]

A very nice image. A bit too much red though giving it a
brownish appearance.

Try pulling back the red and upping the blue a tad.

Greg.

[peter_4059]

Thanks for the advice Greg. Is this better?