Getting back into imaging after a long break

[Gina]

It was 24°C when I took the darks.  It's cooler today so might take some more.  I use -30°C camera temperature in winter.  I guess the camera could do with a bigger fan for summer use.

Edited July 11, 2019 by Gina

[Gina]

Or is it???!!  Cloudy but still warm.  Set the rig going and it's barely reaching -20°C at 100% cooling.  Next Lights I capture will have to be at -20°C.

[Gina]

I think I might change lenses for the next imaging session.  The 55mm FL lens is f1.8 - one stop faster than the 28mm at f2.8 giving twice as much light.  Plus the 28mm covers a lot of lower interest sky in Cygnus.  The screenshot of KStars shows the coverage of the two lenses.  I have rotated the 55mm lens to get the main DSOs of interest viz. NAN, Sadr Region and Cygnus loop fitting in the frame.

[Gina]

There are also interesting areas in Cepheus and Cassiopeia to be explored at this time of year.

[Gina]

Testing plate solving with cropped image Load & Slew action

The solver went on to try to take an exposure but failed because the roof was closed (cloudy anyway).

Edited July 11, 2019 by Gina

[Gina]

Now with full size image.

No doubt about it - solver won't work with too large a FOV!

Conclusion :-  I can't use a 28mm lens with ASI1600MM-Cool camera unless I set ROI to avoid too wide a FOV. 10% reduction in width would suffice.  I expect the solver to work fine with sufficiently narrow FOV.  RESULT!!  At least I think so - proof can come when next we get a clear night sky.

Edited July 11, 2019 by Gina

[Gina]

That's me finished for today.

[wimvb]

7 hours ago, Gina said:

Now with full size image.

No doubt about it - solver won't work with too large a FOV!

Conclusion :-  I can't use a 28mm lens with ASI1600MM-Cool camera unless I set ROI to avoid too wide a FOV. 10% reduction in width would suffice.  I expect the solver to work fine with sufficiently narrow FOV.  RESULT!!  At least I think so - proof can come when next we get a clear night sky.

You only need the smaller fov for plate solving. When you start a sequence, you can set the roi to full size again.

Re star alignment. Try increasing the noise settings, noise scales and noise reduction. Usually this helps.

Hope you're feeling better.

[alacant]

9 hours ago, Gina said:

solver won't work with too large a FOV

Hi. Don't forget to downsample:

[Gina]

2 hours ago, wimvb said:

You only need the smaller fov for plate solving. When you start a sequence, you can set the roi to full size again.

Good point.

2 hours ago, wimvb said:

Re star alignment. Try increasing the noise settings, noise scales and noise reduction. Usually this helps.

I'll look at that - thanks.

2 hours ago, wimvb said:

Hope you're feeling better.

Yes, thank you.  Feeling fine this morning and raring to go 😀

[Gina]

By default there is no allowance for noise and this is what I was using.  I'll try with Noise scales and Noise reduction set to 1 to start with.

Edited July 12, 2019 by Gina

[Gina]

Clear Outside is now showing more cloud for tonight compared with earlier when it showed several hours of clear sky during darkness.  This leads me to think I might be better going for the 55mm f1.8 lens with its ability to collect photons twice as fast.  I thought I would have to rotate the camera but the images already captured indicate the same angle would be fine.  KStars sky map seems to show the wrong camera angle but this may be due to time-of-day.

Here are two screenshots of a stretched Ha image from the other night at full size and cropped to about the FOV with the 55mm lens.  A small slew was needed to obtain best framing.

Edited July 12, 2019 by Gina
lost the text

[Gina]

Ah - the sky map rotates and the FOV rectangle doesn't so the camera angle is not show correctly unless the map is orientated in a certain way.  As I recall this differs from CdC.  Surely there must be a way of showing the FOV correctly on the map otherwise why set the angle in the FOV Symbols editor.  I must be missing something.

[alacant]

21 minutes ago, Gina said:

I must be missing something

Hi. It's lock to celestial pole.

HTH

[Gina]

That's fixed it, thank you.  I had to turn the FOV by 90° to get the right view angle.

[Gina]

Brought the rig indoors and swapped lenses.  This was easy as they're the same external size.  Same length and same size focus ring.  Now I'll set up the focus on terrestrial trees on far hill half a dozen miles away.

[Gina]

Set focus manually and also tested remote focus but the remote focus has stopped working!  Guess I'll just have to hope I have the focus set up well.  Here is a screenshot from PI showing full width plus expanded views using GIMP and further screenshot to get right in to pixel level and this is with resolution of 4656 x 3520 pixels.  There is mist in the distance which is reducing the contrast.  This is certainly the best I can do with manual focussing.  From Google maps the distance to the tower measures 10Km.  I reckon I'm satisfied!

 

[Gina]

Forecast for tonight has improved slightly - still plenty of time for it to change though.  Fingers crossed.

[Chriske]

ok

🤞

[Gina]

These masts are 17Km distant - that should be near enough infinity I should think.

[tekkydave]

Some things I have discovered about the new Pi 4:

• There is currently NO version of Ubuntu / Ubuntu Mate that will run on it. You will need to stick at Pi 3B+ for now if you want an easy install route.
• Raspbian Buster is the only Raspbian version that will run on it. Not an issue in itself but I tried installing the version from the indilib website and got piles of errors. I think their release expects Raspbian Jessie which will not run on the Pi 4.

I have managed to install the latest release of indilib on a Pi 4 running Buster by compiling from source. Follow the instructions on the github page at the link.

I haven't compiled any 3rd party drivers as yet.

I have installed KStars/Ekos on my Ubuntu 19.04 PC and can connect to the Pi 4 remotely no problem. If I can compile the 3rd party drivers I need for my scope (Celestron Nexstar) and get a focuser driver going I should be good to go.

I have used the Astroberry focuser in the past and it works ok. I even have the electronics for it already built from a Previous experiment with an RPi remote controller

Update - the celestron driver seems to be already compiled & ready to run on the Pi 4:

indiserver -vv indi_simulator_ccd indi_simulator_focus indi_celestron_gps

 

Edited July 12, 2019 by tekkydave

[Gina]

Rig installed on mount.  Set pointing up and LED flat panel placed on top ready to take flats for this lens.

[Gina]

Phew - it's hot - 27°C!!

Flats capture in progress.

[Gina]

23 minutes ago, tekkydave said:

Some things I have discovered about the new Pi 4:

• There is currently NO version of Ubuntu / Ubuntu Mate that will run on it. You will need to stick at Pi 3B+ for now if you want an easy install route.
• Raspbian Buster is the only Raspbian version that will run on it. Not an issue in itself but I tried installing the version from the indilib website and got piles of errors. I think their release expects Raspbian Jessie which will not run on the Pi 4.

I have managed to install the latest release of indilib on a Pi 4 running Buster by compiling from source. Follow the instructions on the github page at the link.

I haven't compiled any 3rd party drivers as yet.

I have installed KStars/Ekos on my Ubuntu 19.04 PC and can connect to the Pi 4 remotely no problem. If I can compile the 3rd party drivers I need for my scope (Celestron Nexstar) and get a focuser driver going I should be good to go.

I have used the Astroberry focuser in the past and it works ok. I even have the electronics for it already built from a Previous experiment with an RPi remote controller

 

RPi3B is OK for DSO nebulae.  That's what I'm using ATM.  I might change to the RPiB+ later for faster downloads.  ATM the rig is working so I'm not disturbing it (well not the electronics).

[Gina]

50 Flats each in Ha, OIII and SII - that should do it.

Now if I can get the camera temperature down to -20°C tonight, I have Darks to match.  30,45,60,120,240 seconds.  Last run was with f3.5 lens and I used 45s for Ha so I might want shorter subs for the f1.8 lens.  Superbias is unaffected by the change of lens.

Edited July 12, 2019 by Gina