Thoughts on which imaging rigs to concentrate on

[Gina]

Didn't work   Still can't get mount to connect.  I'm fed up with Windows and USB/serial!!  Looks like it's going to be a wasted clear night

[Gina]

Clearing the com ports works and the Device Manager says Prolific USB-to-Serial Comm Port (COM5) - that's the mount.  But setting the ASCOM port to COM5 still won't connect.

[Gina]

Tried connecting mount via FreeView from indoors and it's connected.  Now to go out and see if it works.

[Gina]

Now have mount working and have pointed scope at the Cygnus region roughly.  Haven't sorted out plate solving yet so we'll see what comes out.

Now imaging in SharpCap at 120s and gain of 430.  Temperature at -30°C.  Sidereal tracking is not good enough at this exposure - probably wants the PA re-doing.

[Gina]

Here is a 5m sub stretched in PS showing definite signs of varying Ha.  I definitely need to get AstroTortilla plate solving so that I can aim at something interesting.

Edited August 16, 2016 by Gina

[Gina]

Moved the scope a bit and this is a 120s sub.

[Gina]

It's all going wrong now.  SharpCap won't give the right exposure or work properly and APT refuses to run   Just tried a remote reboot and now I can't connect over FreeView.  Think I'll go out and shut everything down.

[Davey-T]

At least the Moon is out so a good night to practice

Tonight was a bit of a miracle here compared to the last two, most everything worked, I managed to stop the camera ploughing into the pier, I blame the manual, clear as mud 

Plate solving worked

I got a reported PA error of  00.00.11, not sure if I believe it.

The only thing that refused to work was the GPS which locked on to 10 satellites last night ?

Now taking a 20min HA sub of the Heart Nebula to see if it was all worth the effort.

Dave

 

Edited August 17, 2016 by Davey-T

[Davey-T]

Didn't come out too bad, bit out of focus, got to sort autofocus next, another can of worms 

Clouded over now so going to bed.

Night night

Dave

[Gina]

Found the Cygnus Loop and this image is mostly of Pickerings triangle.  4m exposure with a gain of 500 and cooling to -25C.  No guiding, hence the star trails but this is just a single frame.  A number of 60s subs stacked should give a much better result.

[Gina]

Swapped to APT and decided on 120s subs for this test - slightly elongated stars but I'm running low on space oh the laptop HD so I'm limiting the run to 20 subs.  Each sub is nearly 32MB with this high resolution camera.

[Gina]

Here is one sub processed in Photoshop to stretch histogram and reduce size from 4656 px wide to 1200 and saved in PNG format for upload here.

Edited August 17, 2016 by Gina

[Gina]

Here a 60s sub with the gain turned up a bit and processed in Ps.

[Demonperformer]

7 hours ago, Gina said:

I definitely need to get AstroTortilla plate solving so that I can aim at something interesting.

Gina, Not sure if you have this link, but it is great for setting up AT - which (contrary to my views on its PA-ability) works wonderfully at plate-solving.

http://www.lightvortexastronomy.com/tutorial-setting-up-and-using-astrotortilla-for-plate-solving.html

[Gina]

Thank you   I've used AT before but it's so long since I did any imaging and forget how to do things.  No clear night skies in the 5 day forecast so that seems to be it for some time

[Gina]

Last night (or should I say early this morning ) turned out to be reasonably productive after all    All the hardware working and most of the software.  There seems to be a problem with the under-floor USB cables from warm room to pier and I ended up using a separate USB cable direct from laptop in warm room to camera.  I fed the mount USB-Serial adapter from one of the camera USB hub ports and the other port was connected to my remote focussing system - an Arduino Nano connecting to a little stepper motor with gear drive to the slow-motion focus knob on the Esprit. (Photos in post above.)

Focus control on the laptop was from an app written in Visual Basic with 3 speeds and forward/reverse buttons.  I used this to focus on the moon before going over to the stars.  After setting up and finding a suitable target (Cygnus Loop) in SharpCap I went over to APT for scheduled imaging runs.  I cleared some space from the HD and took 20 subs at 120s and gain of 185 (the preset gain) until I found the gain control   Camera cooling was run at -25°C.  Then set gain to 300 and set up a run of 50 subs of 60s.  Both runs used the Astrodon 5nm Ha filter.

Have to say, I think the ZWO ASI1600MM-Cool CMOS camera is looking very impressive   Histogram stretched versions of just one sub from each run are posted above but I expect to stack and process the collection of subs later today.  Meanwhile I might select a small area of the image to post to show the fine detail.  I'm not sure the focus is the best it can be as I only used the moon image and not FWHM on a star.  Still getting used to using different imaging software from what I've been used to with the Atik 460EX mono CCD cameras.

[Gina]

Yes, looks like the focus could be better.  Here are the two images cropped but not resized so this is pixel for pixel and these are about a twentieth of the area of the full image.  This is a 16Mpx sensor - much higher resolution than I've been used to.  These single subs are just histogram stretched with no other processing so expecting quite a lot really.  Star elongation can be seen in the first image particularly with 120s exposure and no guiding.  Haven't checked PA lately.

 

Edited August 17, 2016 by Gina

[Davey-T]

Coming along nicely Gina, at least you've got motor focusing working, I made a pigs ear of downloading Focus Max and it seems impossible to have another try if the first one fails, not very user friendly .

PinPoint plate solving worked perfectly and quickly, bit expensive but don't mind paying for stuff that works as advertised.

Looks like it may be clear here tonight so may get another chance, may have a try at the Veil haven't imaged it for a few years, bit near the Moon but only practicing.

Dave

[Gina]

Thank you It's alright if you have an Ha filter.  The Veil was far enough from the moon last night but the moon will be about 15° further east tonight and nearer to Cygnus.  Worth a try though

Edited August 17, 2016 by Gina

[Demonperformer]

Looking at the weather forecast, I suspect (imaging-wise) the moon might be the least of your problems tonight ....

[Gina]

Quite right - no chance of any imaging tonight I'm afraid.  Nor for the next 5 nights according to the forecast.  However, I can add a bit to my data.  Later on when the temperature drops a bit I should be able to reach the -25°C I used for imaging last night.  Currently it will only reach -18°C with an ambient temperature in the mid 20s.  I've already taken a set of flats.  Until I get to processing them I can't see much variation across the image.  No sign of dust bunnies but I did give everything a good clean before imaging last night.

[Gina]

Spec for the camera states that "The sensor can be cooled to 35~40°C below ambient".  -18°C with 25°C ambient is a ΔT of 43°C - can't complain about that

[Gina]

Still waiting for the camera to get cool enough to match the sets of lights.  Slowly getting there - down to -21.6°C now.

[Gina]

With a very mild night the ambient temperature never got low enough to let the camera get down to -25°C but it did reach -23°C and I decided to grab 20 subs of 60s and 20 of 120s in the hope that the difference won't matter too much.  This is only a test anyway.  For a proper image of the Cygnus Loop I shall want to turn the camera for better orientation then think whether I want to do a two panel mosaic or use a camera lens to cover the object.  My original plan for imaging the Cygnus Loop was to use my widefield triple rig with camera lenses and Atik 460EX mono cameras.

I don't know if it's my imagination but this ZWO CMOS camera actually seems more sensitive than the 460EX - no, I don't believe it - must be mistaken!

[Gina]

Going back through my topic listing, I've found the last time I imaged the Cygnus Loop - it was July 2014 - thought it was a long time!! 

Cygnus Loop Mosaic with Esprit 80ED and 460EX - WIP

This worked out as needing 6 panes in the mosaic so I was optimistic in thinking I could do it in 2 with the 1600 camera.  Looks like a camera lens will be more suitable.  Mind you, a mosaic with the Esprit and 1600 camera would give a huge resultant image that would be great for getting printed as a large poster.  I know someone in the village who has just bought a printer that will print 2ft wide prints and this could be a candidate   Why do I always seem to go OTT in whatever I do?

Edited August 18, 2016 by Gina