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Old 19-08-2022, 07:35 AM
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New NGC7293 6nahalfours

Six and half hours at 30 seconds and 350 gain...115mm triplet ZWO OSC 2600 unguided on EQ6R mount with reasonable seeing at my cold and dark site.

I started with near 800 subs and did a bit of a cull but subs were reasonably consistent for a change...Stacked in Deep Sky Stacker, Processed in startools and photoshop...

Stars went funny again and I am sure that has crept in somewhere in my processing and of course the colour is to my to my personal taste... I used a smaller section of the sensor 2200 to give the lappy less work when stacking and processing ...but stacking still took over four hours ..maybe more as I went to bed...I have put up the long exposure first but added the one I said was 3 hours but in fact was two hours (mistake) to show the different another 4.5 hours added...

Thanks for looking

alex
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Old 19-08-2022, 09:22 AM
glend (Glen)
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Alex, what happened with the photo on the left? The spectral shifts are not the result of the TS115 optics. Star shapes in the right photo seem more like what I would expect. With a OSC camera it is hard to see how the spectral shift could be stacking related. Perplexing.
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Old 19-08-2022, 09:37 AM
Startrek (Martin)
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Hmm….
For 6.5 hours it looks a bit thin in detail plus there’s some artifact halo around the object and yes stars are affected either by atmospheric issues or post processing ?
The original image for 2 hours worth looks much better to be honest, it’s a 9/10

How was the dew or fog around during the night ?

In regard to stacking time in DSS for hundreds of short subs , I found reducing the amount of detected stars ( Star detection threshold) to between 15 and 20 stars helps speed up the processing time. I think from memory DSS can stack on only 8 detected stars

Also I know I’m an absolute pest but I can’t see any reason to use Photoshop after Startools ( It’s in black and white in the Startools Do’s and Don’ts plus Ivo the developer has warned me against mixing other post processing software with Startools) Saying just because I can and I don’t care is not logic to me. Ivo is a lot smarter than me and I listen to him , everything he has advised me has been spot on. Just yesterday he resolved my issues with SV Decon module and now it’s working really well for me , whereas as before I just ignored advice. Now I listen

Cheers
Martin
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Old 19-08-2022, 11:57 AM
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Thanks for your comments gentlemen but let me offer my excuses

I went into robot mode after mid night and tired as I was did not sleep well and I should not have attempted processing so early this morning...

I was rushing to just get a result post it and try and get some more sleep... my plan it to start over from doing a cull with my wits about me and more attention in StarTools...May be I stacked my culled rubbish?

What does concern me is the first night I had little contrast which I put down to light reflecting from the ceiling perhaps because the lid was not openned all the way plus the lap top throwing out light...well last night I openned all the way and also put the lap top in a box to eliminate it's stray light...however the subs still seemed poor to be honest...and last night I refocused regularly but I am starting to think maybe the dew got at me..I did not check but had the dew heater on but dew seems the only answer so far...maybe I disconnected it or something..I will check into that possibility.

Anyways I am too tired to do anything at the moment...

Also the stars were much worse than we see here and I had to use the repair tool in StarTools to settle them but as you can see not really a good fix.

But most of all thanks for your input.

I will take a rest today so I can try some different things tonight and work out if it's dew or even perhaps the camera....hmmmm I just had an idea.. maybe that oil on the sensor problem ...that fits the pale subs I expect...but I am so tired I will have to rest before I can make it to the observatory...I bet it is the sensor cause my "Lenspen" arrived two days ago and me being a lucky man tells me it has come to get me out of a hole..

Thanks again good nightAl ex x
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Old 19-08-2022, 12:00 PM
glend (Glen)
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Yes reducing the DSS detection threshold is a snart idea, it can be set for a relatively low number of star detected, and thus aligned. It does speed up processing time. It generally picks up the brightest and ignores the dimmer ones, which is fine for objects like the Helix but not so good on wide star field type images.
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Old 21-08-2022, 03:33 AM
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earlier I stacked the wrong batch...this is a new batch 3 hours approx...processed in Startools and not touched in photoshop other than changing to a JPG file...I did not touch the colour in Startools ...the second has a photoshop touch up for comparison

alex
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Old 21-08-2022, 06:20 AM
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Hey Alex you certainly don't give up do you mate, still a bit GREEN at it (couldn't help myself) but your getting there.

Just my poor attempt at some early morning humor, stay well my friend

Leon
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Old 21-08-2022, 09:17 AM
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Hey Alex you certainly don't give up do you mate, still a bit GREEN at it (couldn't help myself) but your getting there.

Just my poor attempt at some early morning humor, stay well my friend

Leon
Good morning Leon and please give my best wishes to Alice. I do hope that you are both well and enjoying a peaceful and kind outlook.

Thank you very much for taking your time to offer your encouragement and your humour as I certainly welcome and appreciate both.

I did read that a predominance of green hints at some sort of issue and I am not sure if my recollection is correct but I think the article said it often indicated out of focus...I have been very diligent with the focus as I refocus every 30 minutes, manually at this point as setting up the equipment to auto focus is on my far too long to do list...there are so many things I plan to do once the imaging is off and running but by that point I am very tired and just don't seen to have the energy to do any more...like last night I uncovered the RASA to test the Asiair plus set up but I had to comecback to the van and fit in a short nap before my scheduled refocus..the openning and setting up was all I could manage.. all I can think is the radiation treatment has effected me even though it has now been a couple of weeks but I get so very tired..after 2 nights imaging I just cant do a third and I am only up until 1 am like not all night.

I was aware of the green but wanted to leave the image unaltered as to colour so I did not fiddle either in StarTools or in Photoshop so perhaps Martin can see first an image not run thru Photoshop which he advised.
I have presented my hypothesis that the green comes from all the trees around me and remember this was a OSC so there was no channel specifically mapped to green...

I plan getting more data tonight if I can fit in some sleep today and later see if I can vary the colour in photo shop...but I have so many things to do it won't be easy fitting in some Photoshop time...so why waste time here...my time here is always rest time...I just did a little work filling some holes and levelling the ground around here then came in and made some tea and came here.


Thanks again Leon.

Alex
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Old 21-08-2022, 09:26 AM
glend (Glen)
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Alex, just a suggestion, but given your problems with colour vision, why not get Sandy to do the colour balancing for you. She seems computer savy and might like to help.
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Old 21-08-2022, 10:11 AM
Startrek (Martin)
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Alex,
Nice re process and images
Somethings not quite right, 2 vastly different images in regard to dynamic range and detail ?
Let’s forget the colour, contrast and brightness for a moment
Did you do any further re stretching or dynamic range enhancement in PS or just colour and brightness adjustments ??
If the former , then ST is not being utilised to its full advantage as the data is obviously there or else PS couldn’t expose what it has exposed in the outer regions
Somethings not quite right with the ST workflow ?
What version of ST do you run ?
I’d be interested in your ST workflow ( and so would Ivo )
You’ve seen my images over the past 2 years or so using my 2600MC , 6” newt , Bortle 8 Sydney skies, and ST with only with limited data , it just works , but there’s some understanding of how to utilise it to full advantage to expose fine detail and DR

Also your stacked data in DSS , if your going to continue using ST should follow ST guidelines and prerequisites

https://www.startools.org/links--tut...acker-settings



Cheers
Martin
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  #11  
Old 21-08-2022, 05:17 PM
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Quote:
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Alex, just a suggestion, but given your problems with colour vision, why not get Sandy to do the colour balancing for you. She seems computer savy and might like to help.
They sometimes help.

alex
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Old 21-08-2022, 05:25 PM
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Originally Posted by Startrek View Post
Alex,
Nice re process and images
Somethings not quite right, 2 vastly different images in regard to dynamic range and detail ?
Let’s forget the colour, contrast and brightness for a moment
Did you do any further re stretching or dynamic range enhancement in PS or just colour and brightness adjustments ??
If the former , then ST is not being utilised to its full advantage as the data is obviously there or else PS couldn’t expose what it has exposed in the outer regions
Somethings not quite right with the ST workflow ?
What version of ST do you run ?
I’d be interested in your ST workflow ( and so would Ivo )
You’ve seen my images over the past 2 years or so using my 2600MC , 6” newt , Bortle 8 Sydney skies, and ST with only with limited data , it just works , but there’s some understanding of how to utilise it to full advantage to expose fine detail and DR

Also your stacked data in DSS , if your going to continue using ST should follow ST guidelines and prerequisites

https://www.startools.org/links--tut...acker-settings



Cheers
Martin
I found some settings I could change in Deep Sky Stacker (no drizzle) and followed the work flow and ended up with this. First is straight from Star Tools second with a touch up in Photoshop but both are very small 130 kb approx...I think my subs are not flash ..looking at anyone of them they look like they are on sand paper...Sure it was high gain but way below subs on other objects ... I still have not looked at the sensor and I doubt if I will be getting out there to night.

Anyways I will try again starting fresh lower gain maybe longer subs, check for oil or ice on the sensor stray light etc.

Thanks Martin I found I needed to change some DSS settings at least.



alex
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Old 21-08-2022, 05:55 PM
Startrek (Martin)
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Alex,
The colour in these latest images is spot on but the file size reduction has probably compromised resolution and quality
I may have sent these DSS doc’s to you before but its my latest revision in regard to DSS and Startools
See attached

My Helix from last year had the following basic ST workflow ( I’m capturing the Helix tonight and tomorrow night again)
1st AutoDev to inspect
Bin 50% to reduce noise ( as long as your oversampled you can Bin to reduce noise ) Your 115 refractor has a focal length of 805mm l think so using the 2600MC and no reducers will yield a image scale of 0.96 arc sec per pixel , so a 71% Bin should work
Crop edges ready for Wipe
Wipe default , bump up dark anomalie filter to 4 pixels
2nd and final AutoDev stretch, use tight ROI around Helix and bump up “ignore fine detail to between 2.0 and 6.0 pixels to achieve the best detail and lowest noise
Contrast use default
HDR not needed
Set Star mask and invert so image is green and stars are white and not sampled
Sharpen use default DSO at 300%
SV Deconvolution ( I’ve just learn to use use the new SV Decon )
Superstructure use Isolate preset and set to 30 to 40
Clear Star Mask
Colour to taste
Final noise reduction ( usually 4.0 to 6.0 pixels depending on how severe noise is )
Save

Hope the above and attached is helpful

Cheers
Martin
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Old 21-08-2022, 08:23 PM
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Hi Martin I followed your approach but I could not help going for 3x drizzle ..colour is different I think ...actually I am too tired to think..but I do like this one on my screen ..goodness knows how it will look here..

it went a bit red and I could not get rid of it in startools but subdued it in photoshop a little.

Martin thanks for all your help and guidance I greatly appreciate all you do for me.

alex
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Old 21-08-2022, 08:24 PM
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Hi Martin I followed your approach but I could not help going for 3x drizzle ..colour is different I think ...actually I am too tired to think..but I do like this one on my screen ..goodness knows how it will look here..

it went a bit red and I could not get rid of it in startools but subdued it in photoshop a little.

Martin thanks for all your help and guidance I greatly appreciate all you do for me.

alex

Addition via Edit...I forgot to bin...so another go and 2x drizzle and I can bin 50%
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Old 21-08-2022, 09:03 PM
Startrek (Martin)
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Originally Posted by xelasnave View Post
Hi Martin I followed your approach but I could not help going for 3x drizzle ..colour is different I think ...actually I am too tired to think..but I do like this one on my screen ..goodness knows how it will look here..

it went a bit red and I could not get rid of it in startools but subdued it in photoshop a little.

Martin thanks for all your help and guidance I greatly appreciate all you do for me.

alex

Addition via Edit...I forgot to bin...so another go and 2x drizzle and I can bin 50%
Alex,

Drizzle only provides benefit for undersampled data where your image scale is greater than say 1.20 arc sec per pixel
Your 115 scope at native focal length of 800mm and your 2600MC is oversampled ( 0.90 arc sec per pixel ) so Drizzle will be detrimental not advantageous. Even with a focal reducer to reduce your fl to 700mm your still oversampled
Drizzle is designed to work with undersampled data ( short focal length scopes say 200 to 400mm fl ) , lots of data and data that is well dithered
One of the negative affect of Drizzle is that it injects a lot of noise in images if not sampled correctly

Drizzle and Binning doesn’t make sense in Startools ( Binning trades off a bit resolution for noise reduction and Drizzle adds noise in regard to oversampled data )

With “oversampled data” your best to do a basic Stack in DSS ( no Drizzle ) then in Startools use Binning ( I use the slider to trial the best Bin setting ) to improve your SNR and then if you want a sharper image particularly with the main structures of your object , use Sharpening and then SV Decon Spatial Variant Deconvolution ( ST version 1.8 ) this new module greatly reduces atmospheric blurring of your image and at the same time tightens your stars to pin points ( It’s taken me a few hours to learn it I’ve got it working really good now )

Cheers
Martin

Last edited by Startrek; 21-08-2022 at 10:30 PM.
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Old 21-08-2022, 11:26 PM
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Thanks Martin..this one then unfortunately is 2x drizzle. I will do another with out that but I will do that tomorrow.
In any event I must say I am happy with all of them one way or another because once upon a time I would have looked at the worst one in awe and rated it way past anything that I could ever do...I always think back to where I started in life which I think of as being 11 years old in a one horse town with nothing knowing nothing..it has been a fantastic journey.
Thanks again and I am really looking forward to see your production.
alex
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Old 22-08-2022, 05:19 AM
oska (John)
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...
Martin thanks for all your help and guidance I greatly appreciate all you do for me.
...
As a lurker I too really appreciate the time & effort you take Martin - Cheers Mate!
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Old 22-08-2022, 10:35 AM
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As a lurker I too really appreciate the time & effort you take Martin - Cheers Mate!
I thank you for your post as people like Martin represent the backbone of our hobby...so many people in this world are jealous of their skills and in an effort to be one up on others keep their knowledge to themselves...Martin is honourable and decent and helps others and deserves recognition such as you have given...and I know there are many people who benefit from Martins input trying to help people starting out like me.

Well said.

alex
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Old 22-08-2022, 10:41 AM
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OK..I copped out on more subs last night..the forcast said cloud around nine which did me a favour as that was the excuse I needed to take a break..I really needed it.

Anyways Martin here is my result without drizzle...
the first is startools only and the second one lets say my art work in photoshop.

Thanks again for all you help.

alex
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