What about the software?

I have new cameras that are more sensitive.   The scope can track, I’ve got the ability to autoguide.     However, what about the software?  This blog post is an update on the software that I’m running with my telescope, and how everything fits together.   There’s rather a lot, so rather than list the software I thought it would be worthwhile to give an overview of my last session which not only shows the software, but also shows how it’s used.


When setting up, I start with the Imaging camera, and filter wheel removed from the scope.  This is because there is not enough clearance to get the scope into it’s EQ Home position with the camera attached.   (The fork arms are not long enough)

Starting with the mount turned off, I set the scope to roughly the home position (pointed towards the pole star… ish) and start my first piece of software.  Enter SharpCap Pro.   This is the piece of software that I use for two purposes.

  • Polar alignment
  • Planetary imaging

Regardless of my target for the evening, I’ll start off with running through the polar alignment wizard.  Using this, I’ve had the best polar alignments from my scope.  To the point where my Autostar handset gives up and says that I’m withing 5″ of arc of the celestial pole.  As the full moon is 1860 arc seconds (approx) in diameter, this is extremely accurate.   It takes me about 15 mins to do get the alignment set, but that’s fine as the scope will be cooling down during this time, so there’s no need to rush.


Once the polar alignment is done, I’ll turn on the mount and perform the two star easy align, using the hand set.  SharpCap helps me here as I can turn on the Reticle lines, making it easy to put each of the two guide stars into the center.   My 9*50 finder scope is good enough to get the guide star to appear on the screen of using the guide camera.

Once the alignment is done, I shut down SharpCap and start up PHD2.  This my choice of software for guiding, actually I think that most people use this program.  This connecs to the Poth Hub which is part of the ASCOM framework. I use Ascom to control my telescope.  The POTH hub allows me to connect several pieces of software to my telescope at the same time without them fighting each other.   This is great as PHD2 wants to communicate with the mount, and so does some other software…..


It’s time to attach the imaging camera and filter wheel.

This also gives me the opportunity to decide if I’m going to make use of my F6.3 focal reducer.  (Which tends to be the normal operation)

For image capture it depends on what target as to which program I’ll choose.  For Lunar or planetary imaging, I’ll opt for SharpCap, as it had the ability to capture movies.

For DeepSky imaging, I’ll opt for Sequence Generator Pro (SGPro for short).


Let’s talk about the deep sky stuff.   I want to have at much of this automated as possible.  Capturing these images can take days worth of camera time, so it needs to be repeatable, and have as little fuss as possible – mainly to maximise the amount to capture time that I can get.  Also it’s not fun to have to sit out with a telescope whilst it’s taking images as it’s cold and frankly can get boring.

What does SGPro do for me?   Well, just about everything.

Firstly, I can pre-prepare the sequence of images that I want to capture.  Lights, Darks, Flats, Flat Darks, Bias for each filter.   Then I can use other software – carts de ceil, Sky Safari, astrobin to figure out the location of the image that I want to capture.  Further to this, having entered the details of my camera I’ve got it setup to be able to use the mosaic wizard to frame the image before I start capturing data.


With all that stuff saved, it means that I don’t have to think about what images I want to capture whilst out in the dark.  This is just the start.  SGPro can make use of PlateSolving to make sure that the telescope is pointed at the right part of the sky.  There are two platesolvers which SGPro uses, one from PlaneWave and the Other from Astrometry.net both of these are installed locally on the laptop so do not need an internet connection.   This make finding the targets extremely accurate.


Once the target is centered, focussing is the next challange.  This can be done manually using the Frame and Focus wizard.  Which is what I have done so far.  However, if you have a compatible electric focusser, SGPro can run a focusing routine for you.  Yep, that’s auto focus.   I’ve not tried it yet, but am building a focusser for my telescope that will allow me to do it.


Once on target, SGPro can communicate with PHD2, and start it up for me.  This will get the Autoguiding going.  Once settled, the imaging sequence will start.


SGPro can refocus if there’s temperature changes, after a given amount of time, or when a filter is changed.  This can save alot of time and help to capture those imagines more efficiently.


Each image captured by SGPro will be saved in the FITS format, which can be processed later.


This post is getting rather big, so I’ll take this opportunity to talk about the processing in another post.

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