Eta Carina

ChrisV (Chris) · #1 26-02-2018, 11:22 PM

3 hours on Eta Carina from 2 weeks ago. 132x (edit: not 192x) 90sec subs on ASI071 80mm F5.9 refractor. Just left it running all night - my scope seemed to keep focus !! A victory.
Captured with APT, processed in PI. I've binned 2x2 and compressed it to get the file size down

Fernando · #2 27-02-2018, 03:46 AM

Hi Chris,

Looks great to me. Congratulations.

Fernando

glend (Glen) · #3 27-02-2018, 07:53 AM

Chris the 80mm seems to provide good image field of view for Eta C. Is that reduced to f5.9 or the native focal length of that scope?

xelasnave · #4 27-02-2018, 08:00 AM

Nice one Chris.
Alex

PKay (Peter) · #5 27-02-2018, 08:22 AM

Great image Chris

You may have 3 hours, and now add another 30...

Try 240s exposures.

Well done.

ChrisV (Chris) · #6 27-02-2018, 11:54 AM

Quote:

Originally Posted by glend

Chris the 80mm seems to provide good image field of view for Eta C. Is that reduced to f5.9 or the native focal length of that scope?

Native F5.9. 472mm focal length. The FIV is just perfect for this beautiful nebula

ChrisV (Chris) · #7 27-02-2018, 11:59 AM

Quote:

Originally Posted by PKay

Great image Chris

You may have 3 hours, and now add another 30...

Try 240s exposures.

Well done.

Thanks Alex & Peter, yes I'd like to get more on it. Maybe get some more next month before it goes too far west for me.

I'm not sure longer subs would help. I used Shiraz's spreadsheet calculator and 60 - 90 sec seems to give near-optimal SNR with this camera, focal ratio etc. Anything above that doesn't improve it much and will just cause more saturation. It does take a long time to register/integrate etc with hundreds of subs though - suppose thats the rub with CMOS cameras ?

PKay (Peter) · #8 27-02-2018, 02:01 PM

Hi Chris

In an effort to get better star colours, I have been experimenting with really short exposure times (less than 10s) and low gain (50 for the ASI1600).
It does work.

So the plan is:

For the stars: Take 100subs @ 10s. Get the darks and bias at the same setting. Integrate these into one image separately.

For the feint stuff.
Do the same for 120s and then 240s.

So we end up with 3 images for the final integration.

Kiarano (Kiaran) · #9 04-03-2018, 03:29 PM

Impressive work Chris.Thanks for sharing.

yoda776 (Matt) · #10 09-03-2018, 11:05 PM

Impressive image Chris. Thank you for sharing from an aspiring astrophotographer

LostInSp_ce · #11 10-03-2018, 10:29 AM

That's a beautiful Carina Chris. Well done

jenchris (Jennifer) · #12 10-03-2018, 11:07 AM

Nice take. If you're unhappy with the depth you can soon add more lights or ha lum.