Cone Nebula

peter_4059 (Peter) · #1 23-01-2011, 11:07 AM

I finally had an opportunity last night to try out the new Ha filter. I managed 180 mins in 10 min subs before I found the QHY8 had some dew forming on the front at which point I chucked it in. I'm dissapointed in the noise in the image - obviously need to go for longer subs however the good news is I have almost no flexure so should be able to try longer subs. I also need to take some 10 min darks as I don't have any in the library and maybe this will improve things a bit.

I've included an image from ESO I was using to frame the object for a comparison just for fun!

strongmanmike (Michael) · #2 23-01-2011, 11:23 AM

That's a great start Peter, I really like your framing and there appears to be some nice resolution there too (hard to tell at this tiny image size though).

Is the noise from stretching? What temperature was it shot at?

My experience with the Sony chip in my SXV-H9 was that it didn't need darks, have you found this?

If you can tame that noise, you will have cracker of a shot

Mike

peter_4059 (Peter) · #3 23-01-2011, 11:26 AM

Thanks Mike - It was shot at -15C. I'm not sure how to tell if the noise is from stretching? It definately got more noticable as I stretched the image.

Peter

strongmanmike (Michael) · #4 23-01-2011, 11:27 AM

What does it look like without specific stretching but just DDP filter applied?

Mike

jjjnettie (Jeanette) · #5 23-01-2011, 12:13 PM

Beaut work Peter.

It's been a long time between drinks up here.

desler · #6 23-01-2011, 12:25 PM

Peter, I'm normally running at -20 and don't suffer from noise that much. Darks do help. You've certainly got the data there and the framing is spot on. Well done.

Darren

peter_4059 (Peter) · #7 23-01-2011, 12:27 PM

Thanks JJJ - same here. I've only had the scope set up a couple of times since Astrofest and don't have much in the way of images to show for it.

Mike, I don't have Maxim but do have the AstraImage PS plugin that has DDP however I'm unsure how to use it properly. The raw stacked image is pretty dim so I assume the noise is due to stretching. Might have to give it a try again tonight with some longer exposures.

peter_4059 (Peter) · #8 23-01-2011, 12:30 PM

Thanks Darren - which scope did you use for the Horse Ha image? I'm trying to get a feel for the exposure length/camera temp/scope aperture/object magnitude relationship.

desler · #9 23-01-2011, 12:35 PM

Peter,

Ed 120 through a Pflat 2. 9 x 15 min subs at -20.

I have to use the flattenr or can't get decent framing. I have also suffered with star reflections without the flattener. Looks great in a sub, impossible to process. Good luck.

Darren

multiweb (Marc) · #10 23-01-2011, 02:44 PM

Terrific result Peter. Gotta be happy with that one. Ha rocks.

gregbradley · #11 23-01-2011, 03:17 PM

Very nice image Peter.

Greg.

telecasterguru (Frank) · #12 23-01-2011, 04:15 PM

Really good work.

ozstronomer (Geoff) · #13 23-01-2011, 04:32 PM

Great shot Peter even without darks added that's still a lovely image, well done

Geoff

peter_4059 (Peter) · #14 23-01-2011, 06:09 PM

Thanks for all the encouragment. When I processed the image this morning I was really disappointed with it however looking back through the IIS posts it looks like it is quite a difficult nebula to capture.

I might have to revise my to do list and start with some easier objects.

RobF (Rob) · #15 23-01-2011, 10:44 PM

Great contrast Peter. Has a real 3D effect to it. Longer subs (and plenty of them) helps conquer noise of course. I was surprised at the difference between say 5, 10 and 20mins in Ha (although I have no experience on this one). With our weather as its been, you can't be blamed for playing it safe with sub lengths though. There's usually a rain cloud on the BOM radar somewhere in the neighbourhood lately.

Now you've got everything tracking so well dithering might be an issue (if you're not already doing it)?

peter_4059 (Peter) · #16 23-01-2011, 10:56 PM

Thanks Rob.

I thought three hours would be plenty but have zero experience with Ha. I started off with 5 min subs and then thought better of it.

It looks like we are going to get a few good nights however unfortunately during the week! I haven't needed to bother with dithering so far due to flexure however I think I've now got that under control (it has added quite a few kgs of weight to the imaging rig though!) I have trialed dithering using nebulosity/phd and it is pretty simple to set up.

h0ughy (David) · #17 23-01-2011, 11:06 PM

lovely shot Peter - a bit more time on it