Horse Head Nebula teaser

[Paul Haese]

I am currently collecting data on this image and am now have some data to present the Ha part of the image. I intend to take something like 12-15 hours of Ha data and at this stage the image contains 5.5 hours. Sub length is 30 minutes.

Of note is that the halos I had with the Astronomiks filters are not present with the new Astrodon filters. The Astrodon filter I am using at present is 5nm latest generation.

I will present several version of this object as I collect the data for each filter. I am interested to see what a bicolour image looks like, a complete narrow band and of course the traditional HaLRGB with the new filters.

For now Click here (http://paulhaese.net/HorseHeadTSA.html)for image.

[tilbrook@rbe.ne]

Wonderful teaser Paul!:thumbsup:

Another one of those images you feel like you could float through, a great 3D feel.

Cheers,

Justin.

[allan gould]

Beautiful and it is the start of a great, detailed image.
Cant wait for the rest of the teaser.
Allan

[Astroman]

outstanding!

[alpal]

The curtain is already showing up & so is plenty of detail in the horse head.
This will be good.

[h0ughy]

that's cool just as it is Paul

[ChrisM]

Looking great Paul. Will be interesting to see what another 10 hours does.
Chris

[strongmanmike]

Looking good Paul :thumbsup: (needs more exposure huh? more exposure ya canna get enough exposure :lol:) actually, I squeezed in 6X5min subs on this just this morning as dawn was breaking...some steady air at that time but oh man, you would have been impressed with the noise in the dark areas :lol:

Mike

[multiweb]

Awesome vista already. Great image scale. Is that the RC12?

[Paul Haese]

Yep lots more exposure. No noise wanted. Why not do 15 minute subs? What NM filters do you have? I have found with the 5NM Astrodon filters I need to do 30 minute subs. At the conference I spoke to Don at length about this very issue. He stated that long subs is the way to go. Jay had the same opinion. I asked if diameter of the objective mattered and each said even if you're using a FSQ106 long subs are the way to go. I know from experience you can use shorter subs because of the diameter but surely 5 minutes is too short.



No Marc, this is with the TSA and QSI. The RC12 would have a much smaller field of view. No imaging has started with that rig yet. Another couple of months yet. Dome has just gone up and I don't have the adapter for the Atlas to STXL yet. Ordered that on the weekend, it should be here in 3 weeks or so I imagine. In the mean time I have to get the pier made up and the electrics installed to automate the dome. Then of course commissioning. I am hoping by new year to have the system up and running.

[gregbradley]

Looking very good indeed Paul. That TSA scope has superb optics.

I don't like the steep angle of the framing though.

Greg.

[naskies]

Looking very promising, Paul. The inverted-Y composition is growing on me... something a little different to normal.

Btw, it might be worth looking at your stacking settings. In the large image, I can see that hot/cold pixels aren't being properly rejected, and I think the bright areas will be smoother too with better noise rejection. When I use PixInSight, I've found that SNR can vary by huge amounts just by experimenting with different settings - I imagine that CCDStack would be similar.

[Ross G]

Even on its own, a beautiful photo Paul.

Love the detail and tonal range.

Great composition too.

Good luck with the final photograph.

Ross.

[RickS]

That looks very promising, Paul!



Mike is just showing off because he has low read noise (probably about 5e- vs 8e- for the QSI-683) with his fancy-pants Sony sensor :lol:

Read noise is the reason why longer subs give you better SNR. It is incurred once for each sub, so you need to overwhelm it by collecting enough signal that the read noise is insignificant. I suspect that 5 minutes is still a bit short for narrowband imaging with Mike's setup but I haven't done the calculations...

Cheers,
Rick.

[renormalised]

Good enough as it is, Paul. Great shot :)

[gregbradley]

Try less than 3 electrons Rick!

Sony is taking over the sensor world. Its only a matter of time! They have won the DSLR market now for the astronomers:rofl:

Greg.

[RickS]

Greg,

Specs for the Trius-SX694 say:

I still want one of the cameras that RonW was talking about at AAIC 2013 with read noise down at 1 e- :eyepop:

Cheers,
Rick.

[gregbradley]

Ah yes you are right. I was thinking of the FLI Microline version:

http://www.fli-cam.com/microline/index.html (under interline and then 694)

Doesn't quote read noise but total system noise of 3 electrons.

Greg.

[Shiraz]

that is coming along very nicely Paul. regards Ray

[Paul Haese]

Yeah notices those too. Some hot pixels but lots of cosmic ray strikes that were not rejected properly. The normal setting is now working it seems. Time to revise that.

[Paul Haese]

That was the EMCCD. Teed up some time with Ron to take a look at what is can do.

[Rex]

Stunning image Paul, can't wait to see the different stages as it progresses.

[strongmanmike]

Actually, shock horror, with the new SX gear, ie the OAG and on fainter objects I have been using 10min for Luminance :eyepop: :lol: I use the 11.8nm Astronomiks, all I have ever used since 2003 :P The Horsehead was literally snapped as the sun brightened the sky, just because it was there and I wanted to have a few subs for the Median combine to work better so 5min was the go :thumbsup: Funny, you said you talked with Martin about super long subs and mega data and that you want noiseless images yet if you look closely at many of Martins images they are actually quite noisey or at least made very dotty by the decon et al :shrug: I am not saying this is a bad thing, clearly it's not they keep getting noticed but what I am saying is some noise is ok...you'll be alright ;) :lol:

Mike

[RickS]

Lucky bugger!

[astronobob]

Nice going Paul :thumbsup: A technically interesting thread too, , there are lots of ways to skin a cat & I remember yrs ago your dedication to imaging & as you still do is inspiring to many :thumbsup:
I am looking real forward to seeing this start up Horsey come together, thats for sure, the detail is already remarkable ! ! !
Rgrds !

[Paul Haese]

Don Goldman and Jay Gabany said the same thing about long subs and mega data. Obviously the goal is to produce noise free images or as close to that as possible. Not a bad goal I would say. Nearly 40 APODs to Martin's name I think I might be required to seek his advice and heed it. :)

[strongmanmike]

Aaaand many do have noise in them, so obviously noise alone doesn't stop you getting APODS ;)

[Paul Haese]

And so do many of yours Mike. Although Martins have less noise than yours. So I will stick to what I know is right. Mega data produces less noise. It does however require more patience to get a better result. The images I have produces over 20 hours have not required smoothing at all. I don't see why you need to put Martin's images down here though. :shrug:

[strongmanmike]

Hang on, hang on, I am NOT putting Martins images down at all and I said that, he clearly produces some of the best images in the World, I am saying that a little noise is really ok and that's all. By all means hammer each object I am certainly NOT saying you shouldn't do this but in the end I believe it is sometimes simply a waste of time to pick arbitrary huge amounts of exposure for the sake of it, that's all and yes my images have noise in them I LOVE NOISE give me NOISE :rockband: :lol: :thumbsup: I use very little smoothing too ;)

[astronobob]

arrr yous two crack me up !

[dvj]

It's a great start and the composition is just fine. Couple of things to try to help with noise. Lower your camera temperature. Bump your sub exposures up to 40 minutes or more with the 5nm filter, do 20 subs.

I rarely if ever use any software noise reduction, but good sigma reject combines are absolutely necessary to eliminate unwanted noise in narrowband images.

I do like the idea of the Sony chip in a Microline. But what is the QE like in the narrowband channels we like so much? If it's low, you'll still have to expose like crazy to get good signal.

[Paul Haese]

Hi John, unfortunately I cannot low the temp. This time of the year the ambient is slowly changing upward and -20C is the best I can do with the QSI683.

Not sure about 40 minutes now that I have started and have so many hours, but certainly something to remember for next time.

Been using sigma reject but only at 2%. I will try a few settings upward from there and see what the results look like.

[gregbradley]

As an aside I think the topic of data rejection would make a good thread as its not well written up anywhere.
I've started a thread to keep this thread on topic here:
http://www.iceinspace.com.au/forum/showthread.php?t=113733

Greg.

[Peter Ward]

Missed this due being OS for a bit...

An excellent capture of a most excellent area of the night sky

Nice one :thumbsup:

[desler]

Got to be very happy with that start Paul. My longest was shorter overall, about 4.45 and all in 15min subs with a 7nm filter.

The 30 minutes subs should have great signal straight from the camera. I'm envious.

Daz