When it all works, almost

The bank holiday weekend promissed good weather and for once it was. I had a good evening imaging The Elephants trunk nebula in Hydrogen Alpha ( Ha ) for another luminance layer, once I had sorted out a little problem with the guiding. It all stemed from having a new laptop, as the asi camera is USB3 and my old laptop was a little slow with its USB2 ports, plus its getting a bit tired in its old age and does not like too many things running at the same time – Stellarium ( I’ve now changed to Cartes du Ciel planetarium software  * ), Astro Photo Tool ( APT ), PHD2 guiding and EQMod for instance all needs to run at the same time when I’m imaging. I got a HP Revolve 810 and docking port, it has a total of 6 USB3 ports and 8Gb of Ram and a quad core processor so it can handle the load put on it. First off I align the NEQ6 mount then fire up EQMod toolbox and EQMod ( its a go between for the the software I use ) then Cartes du Ciel ( CdC ) and plug in the RS232/ Serial converter to the Synscan handset ( the Synscan handset has to be in PC Direct mode, found under utillity options ). Now the hand set can report the mounts position to the computer, Start up Astro Photo Tool image capture software, start asi1600mm camera cooling and connect to the mount. I then start PHD2 guiding connect the guide camera ( asi120mm ) and connect the GPUSB guide port adapter ( this has Optic isolated relays to eliminate ground loop interference ). Pick a target for imaging in CdC and slew the telescope to it, take a short exposure of 10 seconds in APT and platesolve the image with the inbuilt Pointcraft function, this will if need be recenter the object and Synchronise the coordinates to CdC ( so its self correcting ). This all sound very complicated but it only takes a few minutes to do in reality, EQMod for instance only has to be configured once, your site location and mount ( RS232/Serial cable port ) COM port number then just started to run in the background. Lastly calibrate the PHD2 guiding software and start guiding and capturing images, easy peasy right……NOT, for some reason the calibration steps sent to the mount via the GPUSB adapter had no effect on the mount at all, calibration was impossible. so unplug the usb leads to check connection the red light was on the adapter box so all ok with that, close PHD2 and restart, run through the connection setup once more, again all ok and no calibration steps sent ( the red light flickers green when commands are recieved ) to the mount. 20 minutes later and after several failed attempts I found the problem, the USB3 port I was using was a powered charging port that works fine with everything else but for some reason not with the GPUSB box, once it was plugged into a free USB3 slot it all worked as it should and we were up and running, easy peasy. 

I started off with the north america nebula because I wanted to see how well it repositioned the scope from the last time I imaged it, and it was near perfect as any difference was just negligible. I captured the IC1396 Ha data and then slewed to NGC6960 The Withches Broom nebula ( with pickerings triangle ) to capture about 10 images of that in Ha before the heavy mist rolled in about 4AM totally obscuring the sky even the last quarter moon was blocked out.

IC1396 Elephant trunk nebua
IC1396 Elephant trunk nebua

The image above has had a new luminance layer made from Ha data added to it to improve the detail close up.

The one thing you have to make sure of is that your site coordinates and time are the same in all the software otherwise they will not work together, the time comes from the system ( Pc Time ).

I’m going to capture more of NGC6960 tonight so fingers crossed, I think I’ve ironed out all the kinks.

* There are 2 reasons for changing from Stellarium to Cartes du Ciel, firstly I could not get Stellarium to communicate with APT so pointcraft would not work even though I followed all the instructions, watched all the Youtube videos and read all the forum posts I could find on the subject of Stellarium, APT and Pointcraft, CdC was sorted out and connected in minutes. secondly because Stellarium uses a more realistic sky view it also uses a lot more memory to run.

1 thought on “When it all works, almost”

  1. Noticable improvement in detail with the added Ha layer. Didn’t think it was possible to improve on the previous image but what do I know?? Great blog. When’s the book coming out? 😉


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