Horse Head Nebula teaser

[Paul Haese]

Originally Posted by 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-

Cheers,
Rick.

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 (Michael)]

Originally Posted by 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.

Actually, shock horror, with the new SX gear, ie the OAG and on fainter objects I have been using 10min for Luminance I use the 11.8nm Astronomiks, all I have ever used since 2003 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 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 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

Mike

[RickS (Rick)]

Originally Posted by Paul Haese

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

Lucky bugger!

[astronobob (Bob)]

Nice going Paul 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
I am looking real forward to seeing this start up Horsey come together, thats for sure, the detail is already remarkable ! ! !
Rgrds !

[Paul Haese]

Originally Posted by strongmanmike

Actually, shock horror, with the new SX gear, ie the OAG and on fainter objects I have been using 10min for Luminance I use the 11.8nm Astronomiks, all I have ever used since 2003 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 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 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

Mike

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 (Michael)]

Originally Posted by Paul Haese

Nearly 40 APODs to Martin's name

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

[Paul Haese]

Originally Posted by strongmanmike

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

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.

[strongmanmike (Michael)]

Originally Posted by 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.

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 I use very little smoothing too

[astronobob (Bob)]

arrr yous two crack me up !

[dvj (John)]

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]

Originally Posted by 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.

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]

Originally Posted by 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.

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/s...d.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

[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