Nooo... i don't sleep.. NGC3576 Nebula

EzyStyles (Eric) · #1 09-04-2007, 05:39 AM

yes.. it is 5:34am and i pulled another overnighter. It's freezing in melb right now..I hate it when it's public holiday as it tempts me doing these knowing i don't need to work the next day.

anyway, here's NGC3576 nebula very close to ETA. I don't know why not many ppl image this object but i recalled seeing strongman mike's image in sky & telescope thats how i got to know it.

consist of 10 x 5 minutes at ISO400 with the 300D modded. I'm not yet use to the modified camera effect and the processing side of things as i was overly too use to my 350d unmodded. although i think it takes much less effort to process images taken with the modified 300d. Darks/flats subtracted.

Taken through the Celestron NGT-10 guided with Orion ED80 + Meade DSI II.
bigger version will be up on my website shortly... You can view a comparison taken with the unmodified 350D here:

http://www.iceinspace.com.au/forum/s...hlight=NGC3576

A hugeeeeeeee difference!

cheers guys.

EzyStyles (Eric) · #2 09-04-2007, 05:54 AM

oh forgot to mention Baader UHC-S, UV/IR and MPCC used.

Phil · #3 09-04-2007, 06:56 AM

stunning shot Eric nice colour well done.
Phil

FOOTPRINT · #4 09-04-2007, 09:06 AM

Hi Eric,
Good one, look forward to seeing more from the Modded 300D, as you say- A big difference, yes processing is different than the un-modded Cameras and takes a while to get the hang of, anyway with the moon on the way out and cooler weather clear skies, Why sleep when theres so much to be imaged.

cheers......Jim

Ric · #5 09-04-2007, 09:07 AM

What a beauty Eric, thats worth every minute of an all-nighter and such lovely colour as well.

Cheers

h0ughy (David) · #6 09-04-2007, 10:08 AM

Love it, and I bet you now love the modded camera!

RB (Andrew) · #7 09-04-2007, 10:56 AM

Great work Eric.

EzyStyles (Eric) · #8 09-04-2007, 02:25 PM

thanks for your reply Phil, Jim, Ric, houghy and andrew. I was quite impressed comparing it to the unmodded version.

richardo (Rich) · #9 09-04-2007, 02:37 PM

Hi Eric,
the modded 300D is certainly doing it's job in the red wave lengths. Perhaps balance the red back a wee tad. But that's just imo...

Although I know it's pretty much dominated by HII, but there are a couple of subtle blendings of refection in the mix as well being a star birthing region...

This is a pretty interesting area and one that some seem to pass over, or not bother with it, prefering the brighter Keyhole Neb.
Pretty large expanse of nebulosity and star forming region with plenty to see. Love the hot bubble of ionised gas, looks like a weird light bulb.

I had an image published also in Aussie S&T april 2006, pretty close up but I never liked this image of mine as it was really soft and my guiding was off... no wonder it was like a postage stamp in the mag

http://www.baytop-observatory.com/cc...3576HaLrgb.htm

Here is a more recent Ha version with my 10" newt... much better, just waiting for some colour when the weather permits.
http://www.baytop-observatory.com/cc.../n3576-HaN.jpg

Looks like you're having fun with the new setup, and you can sleep when your in the ground Eric...

.... well that's what I say till I get run down and can't shake colds or get to sleep when I want..

keep up the good work!
Cheers for now
Rich

EzyStyles (Eric) · #10 09-04-2007, 02:50 PM

Hi rich. totally agree too much H2 from the modded camera. The UHC-S and UV/IR filter helps lowering this. Before wasn't enough with the unmodified 350d and now it is extremely too much

digging through my old S&T and saw that image was yours. very nice Rich

I was hoping to capture it standing upwards but i didn't want to mess with my focus again. Here's a rotated version done in ps2 and zoomed in on the region.

strongmanmike (Michael) · #11 09-04-2007, 05:00 PM

Hi EZY

This is a great image!

I tend to agree with Richi poo though, the red/magenta looks too bold to me an perhaps a little over saturated? Can you tone it down and see what it looks like?

One good way to test how well the reds are coming out here is to compare the two nebulae NGC 3576 and it's neigbour NGC 3603. NGC 3603 should be "redder" and less magenta because it is twice as far away as NGC 3576 and thus suffers from significantly more interstella reddening. The thing that actually imparts the blue to nebulae is often the H Betta emission and this turns the HII regions more magenta than red.

David Malin mentioned this actually at the 2006 David Malin Awards. He said that too often emission nebulae are presented as very red and miss the blue/magenta component. He also said that often the red and/or magenta are displayed far too saturated and vivididly suggesting this was mostly due to the memories of the look achieved by the polular red bias film in the old days that always showed nebulae as blood red. The film was relatively insensitive to the H-Betta and thus didn't pick up the blue very well, if at all.

Of course there are many ways an image can be presented and no way is "wrong" but I thought these comments were very interesting and food for thought.

BTW it "could" have been my image you were loking at as I also had an NGC 3576 published in AS&T too

(600K)
http://www.pbase.com/strongmanmike20...74724/original

Here is an image showing the distinct colour difference between NGC 3576 and NGC 3603

(550K)
http://upload.pbase.com/strongmanmik...10477/original

Now go to sleep!

Mike

EzyStyles (Eric) · #12 09-04-2007, 10:03 PM

Cheers Mike. coming out from you surely means alot to me thanks for the advise. Here's a different version with the red channel and abit of colour balancing to compare the difference.

Yess. It was your image that i saw in S & T which drew me into imaging it. it blew me away. trying to adjust it like yours

JohnH · #13 10-04-2007, 02:23 PM

Hope to stop pratting about with software testing and capture something myself one of these nights, up to PHD 1.5RC2 now....

Just a thought but would it not be possible to "calibrate" a modded camera for colour by shooting a known colour reference star and adjusting the balance to match? I thought of this after shooting the tarantula neb and getting it all green (had a UHC filter in line - with the unmodded camera it only really showed the O3)...

richardo (Rich) · #14 10-04-2007, 03:45 PM

Quote:

Originally Posted by JohnH

Hope to stop pratting about with software testing and capture something myself one of these nights, up to PHD 1.5RC2 now....

Just a thought but would it not be possible to "calibrate" a modded camera for colour by shooting a known colour reference star and adjusting the balance to match? I thought of this after shooting the tarantula neb and getting it all green (had a UHC filter in line - with the unmodded camera it only really showed the O3)...

Hi John,
you could do this, but how accurate would it be....
In comparison, calibrating on a G2V solar analogue star like A Centaurus, where the rgb = white, you can't go wrong. White is white, not a certain shade of blue or certain shade of say red.
Once you calibrate with the G2V star, it's done, you don't have to worry about calibrating again. Then you can be confident that what ever you image will be pretty close.... of course there's always some tweaking to taste.

Still, I know a few who check with their planetarium programs to see if their stars are accurate. Not even worrying about calibrating their systems.
G2V calibration is just basically a sign post to give you a good idea of where your at when processing if you have no reference and don't want to rely on any one else's images from the net.

Rich