Now guiding on star to West side of mount around 0 degrees Dec and near the Meridian to see if problem reoccurs, graph looks ok but there is a slight regular pattern of error.
Slewed to M92 which is a glob currently at Alt +74, Dec 43 and on the East side of the mount where I had issues last night. I plate solved the image.
The auto focus run looked good
Found guide star by moving M92 slightly off centre. Now guiding. All looked good for a short while. So each section of PHD2 graph is 25 points, so when you have 100 points selected there are 4 sections of the graph. This mean each section/column represents own my case 250 seconds as I expose for 10 seconds, so just over 4 minutes per section. So the errors I saw last night were about 12mins apart. This cannot be the work gear as it has a cycle of 2min 29sec. This is from the latest Paramount manual for the MEII.
Tracking at the sidereal rate, one revolution of the worm takes 149.6 seconds (2 minutes 29 seconds).
The right ascension gear has 576 teeth.
The declination gear has 475 teeth.
The error I am seeing is about 4mins. I cannot continue imaging as every few frames are trailed.
Esprit 120 FHR was 1.99 for Lum and 2.54 on the Ha
Focused on Deneb , 30 seconds exposure produced HFR 2.23
Deneb – 30 seconds in Ha
Solve and Sync
Solve and sync completed on Deneb in Ha
The focus point for Ha was 6217
Now for a quick frame and focus, 30 seconds exposure
30 seconds Ha on Pelican as Frame and Focus test
That looked good, next up was to see if we can image for 5 minutes unguided and see what the resulting image looked like
300s Ha Pelican
Again the resulting image looked very good and no star trails
Clear skies with -18℃ measured by the Infrared sensor on the AAG Cloud-Watcher.
AAG Infrared sensor read -18c so zero clouds
I then tried a 10min image but got clear trailing.
Star trailing at 10 minute exposure
So I set the guiding up with PHD2, went out to the dome and created a dark library as this was not done. I then set about training the guider and then set it running, initially with a 4 second exposure. The resulting guide graph looked a bit bumpy. The ASC looked very clear this evening which was the first time in a while. You could see stars to the left hand edge of the image which is normally obscured by cloud.
ASC Clear skies
We decided to run the guiding assistant in PHD2 and see if there were any changes that needed to be made. It came up with some suggestions including redoing the calibration and changing the calibration step size from 1600 to allow more steps in the calibration, in this case I changed to 1200 to try and go from 3 steps per axis to 8, however I got to 6 steps and this seemed good enough. When I then reran the guiding assistant I no long got the error about calibration. I did have a few suggestions as seen below which I applied.
Guiding Assistant recommendations
So the changes made still have not allowed 10mins images, they are still trailed. So that I do not waste any further time this evening I captured 5 minute images instead of 10 minutes and I will relook at the guiding next week when the Moon get brigheter.
At 1:38 we gave up on guiding and switched to 12″, Autofocus on Lum, 63384 HFR 5.4. Took some 5 minute and a single 10 minute frame guided, scope trailing ?
There were three scopes on the Pelican Nebula (IC5070/IC5067) tonight as GingerGeek was imaging with the Tak FSQ85 from his back garden.
3 Different image scales from tonight
Finished to go to bed at 2:56 am, GingerGeek finished the session by taking flats, warming up the CCD and bringing the scope indoors just after 3am.
Rough stack of Ha (5nm) 10×600 seconds, -15℃ From the FSQ85
Tonight GingerGeek, Bob and I wanted to make sure the newly installed version update for SGPro was working. In particular we wanted to get the sync and solve working, so that we could centre an object, but also the autofocus as the was a major update.
In TSX select an object and slew to itIn SGPro take a quick 5s image of the objectIn SGPro click the Solve and Sync button on the bottom leftIn SGPro the image is now solved and synced to in SGPro
In SGPro right mouse click on the object and select Center Here from the menu
In SGPro select Yes on the Center Telescope windowIn SGPro take another 5s image using Frame and FocusIn SGPro the object should now be in the centreIn TSX from the Telescope tab click on the Start Up button and select Star SynchronisationIn TSX make sure Synchronize mount into existing model is selected and click on SyncIn TSX notice the FoV indicator from the camera has shifted to a new positionIn SGPro take another 5s image using Frame and FocusIn SGPro the resulting image should not have moved
The mount in TSX and SGPro are now synced to the correct position in the sky.
Tonight I wanted to get the PHD2 guiding working when doing a meridian flip without the need to calibrate. A month ago we still failed to get this done, however a little experimenting tonight and changing a single setting has corrected the problem. The setting was the ‘Reverse Dec Outputted After Meridian Flip’ one within the Guiding table of the Advanced Setup, for which I ticked and this fixed the issue.
Reverse DEC output after meridian flip needed ticking!
I then decided to try 2 objects either side of the meridian and that worked manually slewing to each and then guiding. What did not work was the slewing automatically to the object in terms of centring on the screen. It slewed to the star, I could see it on the screen, the first object Almach worked ok, but the second object, Deneb appeared on the screen but failed to centre with the error ‘ Failed to auto centre, aborting sequence’ followed by ‘ failed to centre on object with an error less than 50 pixels’. Plate solving works fine, well at least it comes back with success.
Error message failing to centre
So I tried different sets of co-ordinates from TSX including the Topocentric and 2000.0 sets. Neither made a difference, with 2000.0 data used I still got this set of errors which shows an error in pixels of more than 50 in DEC.
DEC Error when centring
So I decided it might be the very bright object I had picked, star in this case, that was causing the problem. So to further my experimentation this evening I choose two different and less bright objects, M36 and M39, once again on different sides of the Meridian. Success !!
60s uncalibrated guided M39 exposure
So after fixing this I am now happy to go off to bed early (9:30 work tomorrow) with a job well done.
