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Pelican in Ha - First Real Test of Dual Rig


gnomus

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27 minutes ago, PatrickGilliland said:

Nice work Steve - are you running independent software for image sequence on each then? Interesting data on the Ha.  The 5nm will include some Nii which is extra signal for three when compared to the 3nm, I suspect this adds the additional contrast.  I prefer 5 to 3 having had both.

Thanks Paddy.  In fact, I bought a couple of tiny PCs and I run one scope per PC using SGP.  One is the full guiding set up, and the other just focuses, changes filters and takes the 'snaps'.  Obviously, this means that meridian flips will mess things up a bit on one side of the rig.  I figured that for 5-10 min subs this probably wasn't a big deal, but for longer ones I will probably 'intervene' to stop losing a 20-30 minute exposure.  SGP gives plenty of warning as to when the flip will come.  

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1 hour ago, gnomus said:

yThanks Paddy.  In fact, I bought a couple of tiny PCs and I run one scope per PC using SGP.  One is the full guiding set up, and the other just focuses, changes filters and takes the 'snaps'.  Obviously, this means that meridian flips will mess things up a bit on one side of the rig.  I figured that for 5-10 min subs this probably wasn't a big deal, but for longer ones I will probably 'intervene' to stop losing a 20-30 minute exposure.  SGP gives plenty of warning as to when the flip will come.  

Funny, in my mind setting up the software to manage multiple scopes, and cameras does not strike me as challenging.  I design far more complex stuff for all sorts of businesses, just this week I have designed and built a resource allocation algorithm capable of running complex profit, cost and output routines for a tier 1 company.  Surely after a few years the sequence packages can sync a couple of cameras, 1 mount and 1 guider so they all play nicely and sync activities without and issues.  Whoever gets there first might just steal a march on their competitors!  I know I will be signing up when someone gets it right.....

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1 hour ago, PatrickGilliland said:

Funny, in my mind setting up the software to manage multiple scopes, and cameras does not strike me as challenging.  I design far more complex stuff for all sorts of businesses, just this week I have designed and built a resource allocation algorithm capable of running complex profit, cost and output routines for a tier 1 company.  Surely after a few years the sequence packages can sync a couple of cameras, 1 mount and 1 guider so they all play nicely and sync activities without and issues.  Whoever gets there first might just steal a march on their competitors!  I know I will be signing up when someone gets it right.....

The trouble with all this astro stuff is it can only run one instance of the same driver so while you can run two different cameras you can't run two the same, probably more a Windows limitation than the astro software.

I run two instances of Maxim on a dual setup on the same computer and everybody gets along :grin:

Dave

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Yes the issue was that the two instances of SGP got confused about which Moravian camera was which.  I could manually select them each time, but I am prone to laziness, and I knew I would make a mistake. Lakeside and Atik seemed able to handle two focusers/cameras, however.

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34 minutes ago, gnomus said:

Yes the issue was that the two instances of SGP got confused about which Moravian camera was which.  I could manually select them each time, but I am prone to laziness, and I knew I would make a mistake. Lakeside and Atik seemed able to handle two focusers/cameras, however.

 

1 hour ago, Davey-T said:

The trouble with all this astro stuff is it can only run one instance of the same driver so while you can run two different cameras you can't run two the same, probably more a Windows limitation than the astro software.

I run two instances of Maxim on a dual setup on the same computer and everybody gets along :grin:

Dave

Not looked into the tech bit, neither will I, prefer the design and theory then will hand over.  If you can run two 2 x Maxim and it can work out the cameras then it is neither windows or drivers.  It is the software that needs a firm boot up the posterior!  Windows architecture will know the cameras as different as on different ports.  ID each one and jobs done (that said I am no developer!) Just need the image run to review each camera once connected and recognise its sate against the schedule.  If one camera is still downloading the other will wait for it to finish then when guiding settles etc they both start again.  Pretty simple stuff really.  Master schedule, device states, accepted conditions and exceptions.  Workflows that and there is the solution.

 

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1 minute ago, swag72 said:

There is a program that runs dual rigs and coordinates downloads, dithering etc.....

http://prism-america.com/ Who's going to give it a go first? :)

I did look at that but the user interface did not float my boat.  The equipment connection process (when I looked) seemed to be alien and would require reading some instructions.  Not something I am rpone to :)

If they have tidied that up could be worth another look.

 

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I guess I'll stick with 2 instances of SGP then!! Not that I need them running quite yet :) By the time I'm up and running again with the dual rig they'll probably have developed dual control by then!

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I have to say that I am amazed that dual (or more) cameras is not supported in the main systems (MaxIm, SG Pro etc.) as there are so many of us either doing it or proposing to do it and I can't see what the difficulty is - at the end of the day, it is a synchronisation effort with perhaps a simple programmable time offset (maybe 15 seconds or so) to allow one camera to download before the other to avoid noise on the USB download then off to the next dither and so on. Or am I missing something?

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1 hour ago, PatrickGilliland said:

 

Not looked into the tech bit, neither will I, prefer the design and theory then will hand over.  If you can run two 2 x Maxim and it can work out the cameras then it is neither windows or drivers.  It is the software that needs a firm boot up the posterior!  Windows architecture will know the cameras as different as on different ports.  ID each one and jobs done (that said I am no developer!) Just need the image run to review each camera once connected and recognise its sate against the schedule.  If one camera is still downloading the other will wait for it to finish then when guiding settles etc they both start again.  Pretty simple stuff really.  Master schedule, device states, accepted conditions and exceptions.  Workflows that and there is the solution.

 

I can run 2 Lakeside focusers but have to have 2 separate drivers from Lakeside designed for the job.

Maxim can't run 2 X  QSI683 even if they are on different ports as they have identical drivers.

Dave

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Looking at the two images (3nm v 5nm), I like both but for me, the star size of the 3nm wins out and I can't (currently) decide on the contrast aspect although a quick play in PS to get the two contrasts to a close match emphasizes the star size difference! Interesting test images though, Steve.

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great comparison and great images both of them Steve, 1 thing i have noticed i have never seen the belt of gas/dust running round the bottom of the pelican before.

all the ones i have looked at seem to blend it in, but yours stands out quite a lot.

and i know its only my preference but i like the 5nm better, but then i liver in the northeast and every photon counts :wink:

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Congratulations on managing to get the dual rig up and running. This result is lovely.

Thank you for posting the filter comparison too - very interesting as this is a debate I hold with myself quite often - 3nm or 5nm. I have to say that I prefer the 5nm image in your comparison - personal taste of course, but I suppose it is also a comparison between Chroma and Astrodon. Is it just that the Astrodon is better than the Chroma?

Good luck with the continuing double photon hoovering. I look forward to more results.

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20 minutes ago, toxic said:

great comparison and great images both of them Steve, 1 thing i have noticed i have never seen the belt of gas/dust running round the bottom of the pelican before.

all the ones i have looked at seem to blend it in, but yours stands out quite a lot.

and i know its only my preference but i like the 5nm better, but then i liver in the northeast and every photon counts :wink:

There is some, no doubt apocryphal, tale involving a Yorkshireman who wouldn't wear elasticated underwear ..... for fear that they might give.

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Losing nebula signal / contrast in exchange for smaller stars...when the stars are not exactly huge is not a great exchange in my opinion. However, I would also be interested in seeing this comparison for a different nebula one more purely H-a maybe the California. 

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Very well done Steve.  That is a superb effort indeed.  Congratulations.  I am also thinking of a dual rig some point soon.

Small matter of needing another FSQ85 and another QSI 683 (not got the first yet.....!).

EDIT: I'm still convinced the 3nm is the one to have.

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I like our dual rig. On the basis of this post I also like your dual rig!

By definition a dual rig is worth an F stop over a single rig. Doesn't sound like much, does it, if you put it that way? But it is. 

I don't know the correct answer to this question so I just give you the question: on the French forum a guy suggested that, since my 'x' hours of data were captured on two camera/scope systems, they only counted as x/2. I don't buy this at all.  It seems to me that residual noise in both images will be halved when they are combined. And twice as many photons have been collected. I'll be happy to be corrected by a statistician.

Then there's Belly-Up Syndrome. Sometimes (just ever so occasionally and never here, ever, honest...) a rig goes belly up. But both don't both go belly up at the same time so you get out of jail for half price.

And then there's the F Ratio Reality Check. F5 is something you can just buy and use. F4 is getting an awful lot more dfficult. Yes, twice as fast - but twice as difficult? More tha twice as difficult? Discuss...

Olly

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I'm not a statistician, but isn't running two setups the same as running one setup two nights in a row? It's two separate sets of data that are combined, so no, I can't see how it would become x/2. 

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4 minutes ago, Erla said:

I'm not a statistician, but isn't running two setups the same as running one setup two nights in a row? It's two separate sets of data that are combined, so no, I can't see how it would become x/2. 

Two clear nights in a row :eek: what paradise are you living in :grin:

Dave

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Just now, Davey-T said:

Two clear nights in a row :eek: what paradise are you living in :grin:

Dave

It was rather good until yesterday, but yesterday I received several items from FLO and behold - biggest downpour in 20 years ☔️ ? 

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42 minutes ago, ollypenrice said:

I don't know the correct answer to this question so I just give you the question: on the French forum a guy suggested that, since my 'x' hours of data were captured on two camera/scope systems, they only counted as x/2. I don't buy this at all.  ....

I'll have a stab.  We are trying to ascertain the most accurate estimate of 'actual' signal.  The signal is the signal and so is independent of the camera.  Noise is random, and so is also independent of camera.  That being the case, I fail to see what difference it makes if the frames all come from one camera or if every frame comes from a different camera.  That second proposition would be an expensive experiment though.

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