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Winter Doldrums

Started by Carole, Dec 30, 2018, 12:09:54

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Well I finally got my mount in from the van yesterday and installed it in the obsy.  Doubt we will get to DSC again until early Spring.   :cry:

Have to resign myself to limited capabilities during the winter.  Also limited FOV as next door's tree has grown a lot and now I can only see Orion for a short while then I have to wait until it is well past the Meridian.  Once upon a time I could image it all evening.

I am going to use this time for experimentation and fixes. 

i.e. I want to try to get plate solving working if I can. 

My Newtonian went out of collimation back in the Summer and I have been unable to get it back as it was even with help from Mark, Roland and Lorenzo. 
It's almost back in collimation and I have done a star test, but I still think it needs another tweak, so just need to get outside and do some actual images and see how it turns out. 

Might consider tackling my cone error as well, if I feel brave enough.

You lucky people out there who have dark skies, I envy you.  Thank goodness for DSC though, my saviour.



I planned to get out there this week Carole, but thick cloud persists. its been so long I  dont know what my long term viewing window is now, regarding trees etc     
It is healthier to be mutton dressed as lamb, than mutton dressed as mutton!


It's supposed to be clear Thursday and part of Friday.


The Thing

Its been so cloudy here as well, even with the forecast cold snap it looks like there won't be a clear night anytime soon. I've been doing the same Carole, tweaking and fixing.

For plate solving you really want it initiated by your capture program. The main reason plates solving fails is the FoV is not right, or the stars are being confused with noise.

Using APT there are two plate solving choices, three if you include Astrotortilla which uses APT rather than the other way round. The N.I.N.A capture program I have been using recently has very fast plate solving built in, you just need to download a catalogue to a folder and point NINA at it.

Happy New Year!
Cloudy? ¯\_(ツ)_/¯ (Gallic shrug :))


Hi Duncan, yes I am going to try plate solving with APT - I have already installed the extra programmes it needs, but need a live sky to try it out on.  I am not great at tricky IT stuff and Astrotortilla looked far too complicated for me.

Roger already showed me how to use platesolving with EQMod and Astrometry.net but that relies on WiFi which is fine when I am at home.  At Cairds I don't have a Wifi connection and am not keen to use a hotspot from my phone as I don't have a lot of data per month.  Also the Wifi connection at Cairds isn't consistent.   It worked fine on simulator but every time I try it on a live sky, it plate solving OK, but most of the time it doesn't label any stars so I have nothing to sync on.  It worked once, which is not exactly reliable.

Wish me luck.


The Thing

Hi Carole,
To test the platesolver you can do the following:

In APT you can use the Img image browser tab to find a suitable sub and then double click on it to load it.
If you have loaded Planewave2 as the platesolver you will need to put approximate coordinates in the PointCraft dialog or choose the object in the ObjectBrowser as it needs a starting point, in normal use APT can pick this up from the mount. If you have also installed the All Sky Platesolver and appropriate indices the you can do a blind solve and don't need the coordinates.
You don't need to be connected to the camera but will need to put the focal length used and CCD dimensions and pixel size in on the Tools tab - in practice these are picked up from the camera when you connect it.
Then click Solve. A sub with a hundred or more focused stars should only take a few seconds to solve and will time out after 120s by default.

Hope that helps

Cloudy? ¯\_(ツ)_/¯ (Gallic shrug :))


I have installed All sky plate solver but I think Planewave did not install for some reason, it was a few weeks ago now and can't quite remember.

Will it work with just All sky platesolver.

How well does it work with a DSLR which is not great on live view?  I only ask because there was one target I was thinking of doing with the DSLR mainly because of FOV too big for my small Mono cameras.


The Thing

It will work with a DSLR just fine, select it from the list at the bottom of the tools tab for testing and then pick any sub or even a processed picture taken with that camera/scope combination for testing. I used to use a 5-10s exposure @iso800 for platesolving with my SCT at f5, you may get away with a couple of seconds, definitely won't work with Liveview in my experience, it's just not sensitive enough to capture enough stars.
Cloudy? ¯\_(ツ)_/¯ (Gallic shrug :))


Thanks for the tips on APT Duncan
Carole: I have a chainsaw, if your neighbor is amenable to some pruning.

Synta mount, a bunch of telescopes and a shed (on wheels).