First of all tonight I have taken darks for 300s that are needed for the earlier data. However I am still suffering from the QHY168c disconnecting from the laptop, this time in TSX. I have upgraded the software yesterday but this has not made a difference, so it must be something to do with the way there USB cable is connecting. I will attempt to troubleshoot when I get home. Right now I have switched to Ezcap again which seems to be ok.
I have setup over by Mark and will see what this location is like behind the pool building. I have found that the WiFi is weak or non existent. Also the staff room is nearby and the light is constantly on so maybe not the best place to image from.
@00:03 NGC 6352 30s -20℃ I took a single exposure of this.
First thing tonight is to complete taking the darks from yesterday, so I need 20 x 120s -20℃, but also the flat darks I forgot for the 0.35ms flats. Then I will move to taking longer images tonight. The challenge with open clusters is that you need short exposures so you don’t oversaturate the stars.
@22:50 Omega Centauri 30s -20℃
Omega Centauri
@23:20 Centaurus A 300s -20℃
Centaurus A
@00:09 Makemake 120s -20℃ x 10
@00:29 Haumea 120s -20℃ x 10
@01:07 M8 Lagoon 300s -20℃ x 24 (focus drifted so review later images)
Finally got our bags today from the airport. Having arrives on the 2:05pm flight and not hearing from BA by 4pm, Lawrence and I headed off down the mountain in search of the 4 missing bags. It took just over an hour to arrive back in the Cicar car park.
Once there we headed inside to be told the the Iberia desk, which deals with lost and late baggage was only accessible the arrivals hall and so we were told to go through the exit doors and not to worry about the police. So we nervously😱 walked through and were greated with the sight of all the lost bags!
Blurry Bags
It took some 20 mins to sort through the paperwork before we were pushing the bags back to the car for the 1 hour drive back up the TF1 and TF38.
After a hearty dinner, which was absolutely delicious and filling, we headed outside around 9pm to start setting up. This took me the best part of 2 hours to put the gear together after ferrying it from upstairs and then another 60 mins to calibrate and be ready to image. First up tonight is M23.
@ 23:55 started on M23 Open Cluster, 30s -25℃ exposures so not to saturate the stars.
M23
after 87 images escape hung!
@ 01:20 started on M18 Open Cluster 60s, 10 -20℃ or so images this time using TSX to image and then refocused and took 80 images in total.
M18
@ 3:22 started on M26 Open Cluster -20℃ took 68 at 60s
I’ve taken the plunge and dipped my toe into the CMOS world. Since I didn’t have any OSC experience I chatted with DSW (has a QHY186c) and decided on the QHY286C. This I purchased from Bern at ModernAstronomy who has always provided excellent service.
The issue with APS-C sensors when coupled with the Takahashi FSQ85 is that the edges start to show signs of star elongation, I already see this on my Atik460. This can be corrected with the FSQ-85 flattener (ordered from FirstLightOptics) which has the effect of slightly increasing the focal length but also reduces the back focus from the native 197.5mm to 56mm.
Effective Focal Length
455mm (f/5.4)
Image Circle Diameter
44mm
Metal Back Focus
56mm
FSQ-85 EDX with Flattener 1.01x
This means that I can’t use my existing Atik OAG->Atik EFW2 and Atik460 because it’s total distance is 59mm (22mm+24mm+13mm) so it’s out by 2mm even once you include the filter effect on the back focus. Note – This is also true for my Starlight Xpress configuration.
I do not understand why Atik could not have got to within the 55-56mm range by shaving off a mm here and there 🙁 I may need to replace all Atik gear when I convert to mono CMOS or replace the OAG with a guide scope.
So onto the QHY268C, the OSC CMOS unfortunately has a CAA tilt adapter instead of a direct thread connection. This wastes 11mm of precious back focus giving a total distance of 23.5mm whereas the recently released QHY286M CMOS has a 12.5mm back focus !!!!
Also the QHY268C does not have an IR/UV cut filter in place so you need to buy an additional filter and holder and add that to the cost and factor in the adapter and distance needed …. I’m starting to regret this purchase more and more !
Source – QHYCCD.com
Back to the Takahashi Flattener (TKA37852), the back focus is 56.2mm but we add on the filter thickness as it changes the light path (2mm/3=0.66mm) so ~57mm (56.9mm), the imaging train is as follows :
Adapter
Distance (mm)
Accumulated Distance (mm)
Connector
OU031
2
2
M54(M) -> M54(M)
QHY 020770
4
6
M54(F)
QHY Spacers
14.4
20.4
screw
QHY OAG-M
10
30.4
screw
QHY 020055
2.5
32.9
screw
inc filter
0.6
33.5
–
QHY CAA adapter
6
39.5
screw
QHY268C CMOS
17.5
57
screw
FSQ85 Flattener to QHY268C imaging train
The combined weight is 1365g so I may need to adjust the balance of the scope a little as it heavier than my Atik460/EFW2/OAG setup at 1080g.
Completed – Imaging train ready for first light
I may have to adjust the spacers a little but I won’t know until I have received a 2-inch Optolong L-Pro light pollution filter which is currently on back order from FLO.
Transmission chart for Optolong L-Pro
QHY268M
The recently released mono version of the QHY268 looks like it has a proper screw face plate with a more acceptable back focus of 12.5mm. This is more reasonable and would allow me to couple a filter wheel and OAG as well not requiring a IR/UV cut filter.
Like SyedT on StarGazersLounge I could go back to using a guide scope and ditch the OAG and then the imaging train could incorporate a rotator :
I was thinking of a rotator for the remote Esprit120 which has a generous back focus of 76mm so I should have no problems there but that will be another adventure for the future !
The most funny thing about moving to a new house is assuming you have understood your horizons correctly, well at least I found it funny when I got it wrong. After several attempts to catch the conjunction, traveling out to a nearby field with low horizons, Christmas Eve was no difference. I had set off, this time with the Esprit 120 and QHY168C and on arriving at the location realising that the weather was too cloudy to grab the conjunction.
So off I went back home. I decided to wonder up the garden to see if the weather had cleared when I returned, to find that not only was there a gap on the clouds, but also I could see Jupiter !!! This meant only one thing, that my South West horizon was not +15 degrees but actually +4 degrees! Wow that is good and lucky.
View South West , observatory is going to be in front of the foreground trees
I ran back to the car and started hauling the travel scope to the building site of IMT3b which is currently a vegetable patch, this is around 200 feet away from the car part way down the garden. It took 5 trips to move all the equipment, good for my Apple watch exercise rings, not so good for the setting of the conjunction of Jupiter and Saturn. By the time I setup and slewed the telescope round the pair were setting behind the ancient forest in the distance but I managed to snap a single image! Perfect.
Jupiter and Galilean Moons with Saturn below – 120 Esprit and QHY168CCropped
So during the ongoing Human Malware situation we have been concentrating on imaging asteroids, comets and more recently performing exoplanet measurements on the 12inch RC than long exposure deep sky astrophotography.
Astronomy is one those hobbies that is for most part is sole activity for the dark early hours of the morning and these days is usually done remotely. It was therefore disappointing that when one of the team went to use the Sky-Watcher Esprit 120ED for a night of astrophotography and found that he was unable to open the Optec Alnitak Flip-Flat. As the lockdown and travel restrictions progressed due to the initial wave of the human malware situation the issue was soon forgotten as we continued our focus to performing exoplanet observations on the 12inch RC for the ESA Ariel Mission.
Now that IMT3 has been decommissioned ready for it to be reborn as IMT3b at it’s new rural darker sky site I decided to take the opportunity to retrieve the FlipFlat and diagnose the issue at home on my desk.
Using the Alnitak controller software, I could hear the motor running but it never seemed to complete the close or open. All it continued to display was the TIMEDOUT message as shown below.
Timing out !
I sent an email off to the vendor I purchased it from but after a month I got no reply. In the hope I would not be left with an expensive paperweight I reached out to Optec. After quite a few weeks of getting no reply I was pleasantly surprised to receive a message from Jeff Dickerman (President) of Optec. Jeff apologised for not responding earlier and offered to help resolving the issue. The error message seemed to be a known issue and it was generally an easy resolution which required taking the box apart. Jeff sent me instructions on how to take the unit apart and fix the problem.
You’ll see the motor is attached to an internal wall with a modified shoulder screw and stack of Belleville washers. These spring washers are used to allow the arm to slip when someone grabs the lamp and physically tries to force the cover closed. Unfortunately they can also allow the arm to slip during an open or close operation which leads to that dreaded “TIMED OUT” message. Optec have redesigned the stack a bit to eliminate this issue going forward.
To correct, you might be able to adjust the washer stack by removing the lock nut and sliding off the washer stack to the pivot arm. Check carefully to see if the shoulder screw protrudes beyond the pivot arm. If so, rather than installing the cork washer next, install a 5/16” ID washer first to cover the exposed shoulder. Next add the cork washer and stack of Belleville washers. Finally screw the lock nut back in place and tighten while holding the shoulder screw near the motor (this is important to avoid breaking the internal motor gears).
Step 1 – Pry open clamshell
Step 2 – Shows what to secure
Step 3 – Tools needed
Step 4 –
Step 5 – Check shoulder visibility
Step 5a – Shoulder
Step 6 – Washer Stack
In the end I decided to courier the unit back to Optec for repair as I did not want to render my unit completely useless in case I made a mistake.
I’m extremely grateful to Jeff, Tina and the team at Optec for all there help, patience and understanding. I’m a very happy customer and the flip-flat will be rejoining the Esprit120 when the IMT relocation is complete at it’s new rural location. I can then do a Homer Simpson and annoy Dave with “Flap goes open, flap goes shut, flap goes open ……”
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
So back off to Combe Gibbet again tonight for hopefully a full night until dawn and with a coat. I met with my friend Alan for once again some social distancing astronomy. Again Alan had a much better 4×4 car to get up to the gibbet than my little electric Nissan Leaf, however once again I managed to make it there.
Sunsetting with Esprit 120 and Alan in his chair
After setting up, it quickly became apparent that I forgot the guide camera as it was still attached to the Mak180 that I thought I would leave at home tonight ?
Quick look and focus on the Moon
So despite the slight setback I polar aligned on the uneven ground and managed to get the scope pointing in the right direction. It took me a while to work out why it was not pointing at the objects when slewing with a perfect alignment, then I realised I had the location set incorrectly. A quick look at my GPS on my phone and I input the coordinates into The SkyX and the target was nearly spot on. I adjusted, performed a sync and then was able to slew continuously thought the night with the object in the FoV.
As I was challenged with no guider I could only take 2 minute images and if in the West low down then 1min. So I stetted for those 2 exposures along with 30 seconds for one particular object.
Below are the lost of targets I went after and imaged. I tried to get 15-20 minutes in total for each. We had some early night high cloud, the wind had again dyed down after sunset and although cold, we were both wrapped up warm, although later in the night Alan became cold so wrapped himself up in the dog blanket from the car ?
First up was M44 Beehive Open Cluster, which filled the view nicely so I took 20 x 60 seconds, careful not to saturate the stars. The QHY168C camera was set to Gain 7 and Offset 30 with a temperature of -20℃.
M44 60s
I then tried SH2-129 emission nebula but no luck, it was not registering at all at such short an exposure. I had a similar issue with SH2-155 Cave nebula. Both of these I will try again when I have my guider.
I then slewed to NGC 6888 Crescent nebula and took 20 subs of 120 seconds.
NGC 6888 Crescent 120s
Next tried to image Trio in Leo M65, M66 and the NGC but I realised I had already imaged, although not processed and the image trailed at 1 minute due to its westerly location. So instead I headed for NGC 7243, a lovely Open Cluster in Lacerta and part of the Herschel 400 at 60 second exposure.
NGC 7243
Next I looked at the double cluster in Perseus and decided to quickly take a few images with the Esprit 120 ED even though it was not on my original target list. Due to its bright stars I took 40 x 30 seconds.
Doublers Cluster in Perseus
Now it was time to grab an image of Comet c/2017 T2 PANSTARRS which was located near a galaxy called the Coddington Nebula. I purposely got the comet at the very edge of the frame to get the galaxy in, although I noticed the tail was pointing in the opposite direction than shown on Sky Safari.
Comet C/2017 T2 PANSTARRS and Coddington Nebula
The night wass really dark, even though it is not true astronomical darkness, the location really helps. The image quality is also much better. I slewed to NGC 7000 the North American nebula that Alan was also imaging. Again 60 seconds was probably not long enough so I need to come back to this object when I get my guide camera fitted.
NGC 7000 North American Nebula 60s
Finally just as dawn was approaching and the light was clearly increasing, I took a few images of Comet C/2020 F8 SWAN to see if I could see it. Was was apparent was it was super faint even at 60 seconds !
Comet C/2020 F8 SWAN
So as dawn approached, Alan and I took flats, darks and flat darks.
During the night we viewed through the 4″ binoculars the Moon, Venus, Mercury, Double cluster, M39 Open cluster, M57 Ring Nebula, Alberio, M56 Globular Cluster, Saturn and Jupiter. Unfortunately I packed up the binoculars before I remembered Mars was up ! So packed up the car, ands drove very tired 50 minutes home.
Opened dome early switching the safety for the brightness on the new AAG. The first thing to do tonight was to calibrate a little but more the infrared sensor which informs the cloud coverage. This was suggesting it was Cloudy, borderline Overcast and given it was very clear with a hint at wisps of cloud I adjusted the couple of figures for the sensor, from -17 for Clear to -14 and from -14 for Cloudy to -12.
I then set about taping up the USB and power for the SX camera on the Esprit. This is because the connectors supplied are clearly not in tolerance as I have tried many cables and they call fall out. The tape should suffice for the moment and now the camera reconnects to the NUC computer running SGPro.
Tape for USB cable
GingerGeek and I started to have a look at the sky around 9pm. The sky was not totally clear with some wisps of cloud. We tried to get to a point where we could test guiding the 12″ through the Esprit, however as ever the clouds rolled in. However, during setting up the SX814 camera on the Esprit as the guider and performing a darks calibration run we got an error on the USB bus again (we get lots of USB errors) which not only kicked out the SX814 but also the AAG weather station. The problem was it almost killed the AAG software and we had to cancel the process running to resolve. This meant we lost all the settings in the AAG so we have tried to rebuild as per the new screen shots below.
AAG Weather Station New Settings
So instead we re-ran the Flats Calibration Wizard for the OS with the camera set to Gain 139 Offset 21 and also another run at Gain 75 Offset 12. The reason for re-running is that I suspect the flats we have are ever so slightly over exposed at 30-32k rather I prefer them to be at 22-23k.
We also created 2 new profiles that were simply named so we can see them in the list and simplify the naming convention and amount of profiles needed. We will choose the guider on the night within one of the two profiles created. We will also look to review and simply the other profiles for the two additional OTAs tomorrow and delete the remains profiles given the large number we now have.
The plan for the night (to try using the Esprit120 as the guider for the OS 12″ if it is on the West side of the Mount) was scuppered as we couldn’t connect to GingerGeek’s SX814 camera. GingerGeek checked in device manager and COM7 is missing so we suspect the USB cable has dropped out again.
Following on the the news earlier in the day of the SN in M61, I slew to it and grabbed some 300s unguided subs ( which also proves that it is the guiding that is moving the mount unnecessarily … but we knew that already !). Thare was a suggesting on the evenings group Zoom call that the drift might be due to ‘Cone Error’, but I found several posts stating that ‘Cone error does not affect guiding’. After M61 dropped into the weeds I slewed to M3 and grabbed some Luminance frames shutting down very tired at around 4am.
Chineham Scouts say ‘Thank you’ on Zoom session whilst viewing the Moon
After helping with a BAS Outreach event using Zoom to share images from IMT3 of Venus and the Moon with 1st Chineham Cub Scouts (to help them acheive their Astronomy Badge) I joined Dave and GingerGeek for a joint observing session chasing Comet C/2019 Y4 (ATLAS) with Dave’s 12″ OS.
Comet C/2019 Y4 ATLAS through 12″
I continued to observe after both Dave and GingerGeek called it a night, my aim was to get some data from the Esprit 120 of C/2019 Y4 (ATLAS) as the previous nights run had been terminated when the clouds rolled in.
Quick 10min Exposure through Esprit 120 Comet C/2019 Y4 ATLAS
I set up another Profile in SGPro for GingerGeeks Esprit 120, adding his Lodestar Guider. C/2019 Y4 (ATLAS) was too far from the equator for the Calibration of the guider in PHD2, so I slewed to Bogardus in Auriga, cleared the calibration data for the Lodestar and re-calibrated it. I was then able to get two 10 minute guided exposures with the mount tracking at Sidereal rate before the comet disappeared from view below the roof line of a neighbouring house.
Having lost Comet Atlas for the night, I checked Heavens-Above for other candidates and found C/2019 Y1 (ATLAS) was about to drop below the horizon, but C/2017 T2 PANSTARRS was reasonably well placed, albeit a bit low, and only a short slew from where the telescope was already pointing. After slewing to PANSTARRS and a 5arcminute JOG Up, Left, Down, Right and Down I had it reasonably centred in the FoV. The first 10 minute exposure had star trails, thought I was guiding but found the Mount was still tracking at ‘Custom rates’. The next 10 minute exposure also had stars trailing even though the PHD2 Graph looked fine. I then discovered that with the SGPro profile changes I’d made I hadn’t connected to the ASCOM Telescope Driver for TheSky. The next 10 minute exposure was not much better as by now I’m imaging down in the weeds 🙁 . Time to find a new target … as it is up and really bright drowning out most objects I slewed to the Moon for a few final shots of the evening.
So early on as always I opened the dome to cool down. Tonight Bob, Gingergeek and I want to image Venus in the Pleiades. Even before it got dark and as I slewed the telescopes to Venus, it was visible straight away so I took a quick image, 0.001s from both the 12″ and Bob’s FS102.
Venus 0.001s exposure from the OS 12″ during daytimeVenus 0.001s exposure from the Tak FS102 during daytime
I then went off to watch TV with Helen whilst Gingergeek and Bob grabbed some more images of Venus.
Around 10pm I re-joined Bob and GingerGeek and we set about imaging Venus as it passed by M45 Pleiades in the Tak FS 102. We then went on to perform autofocus on the Tak followed buy setting up the autofocus on the Esprit 120ED
Before the clouds decided to put a stop to play, we took some images of M53 the globular cluster on the Esprit around 00:10am using the Luminance filter.
Quick stack and stretch of M53 from Skywatcher Esprit 120 ED
@18:47 finished 20x -25℃ Flats 0.06s now taking Darks, will do more flats later when the cooler can get to -35℃ which right now it can’t as ambient outside temp is 7℃ so I can only get to -33℃ at 100%
ZWO Ezcap software for acquisition of Flats and Darks
@21:47 just finished Flats at -35℃
@22:49 started imaging Whale and Hockey Stick for Herschel 400
@00:47 I have 2 hours worth of data, performed meridian flip and continued to image the Whale for another 2 hours whilst I went to bed
I started setting up before dusk and the scope was ready for my on the patio once darkness had fallen. The first thing to do was use Polemaster to get the polar alignment roughly done.
Polemaster prior to alignment
@19:43 finished Polar alignment and started PHD2 drift alignement
Drift alignment for the azimuth
@20:07 finished drift aligning in Dec
@20:23 after doing the washing up I am now back to do the drift alignment of the altitude
Drift alignment altitude
@20:29 finished drift alignment in the altitude and did not need to adjust
@20:43 slewed to M35 and set the camera temp -25℃ and its running at 40%. I have set Gain to 7 and Offset to 30
I then joined the BAS Zoom call along with many others from the society. I shared my screen and explained the problem I was having that the DEC axis was still drifting. Mil Dave took me through the settings and it transpired that I had the Dec Guide Mode set to North rather than Auto. This meant it was not correcting for the error as it drifted South., I set to Auto and PHD started to correct! It now works 🙂 Thanks Mil Dave!
PHD Dec Guide Mode Setting to Auto!!!!!!!!@
@21:20 I had started gathering 5min exposures of M35
Quick stack and stretch and plate solve and annotation of M35
@23:00 finished capturing M35 now waiting for M65 Trio in Leo to go across the meridian
The SkyX Trio in Leo
@23:46 started imaging Trio in Leo although there is some high level cloud
Back out again tonight for a short period to look at guiding again. So with everything setup and a longer USB 2 cable in use I am now sitting in the warm Orangery. I will try again with the PHD2 software to guide and EzCap to acquire images from the QHY168C. I have set the Gain to 7 and Offset to 30 as previously used on my other QHY168C when used in Tenerife.
I polar aligned using PoleMaster. Then set about syncing the scope with Betelgeuse. It was only off slightly. The sync worked fine tonight. I then slewed to M35 and started the PHD2 guider software, selected a guide star and calibrated the guider. This worked well first time proving my new step size of 4 using a small ms time for the pulse worked.
Then I started guiding and very quickly realised the same problem as yesterday with DEC drift upwards. No amount of fiddling with the setting such as Hysteresis or Aggressiveness changes the constant upwards drift. I then remembered that I could calibrate the settings as the other night under Guider Assistant. I ran this made the changes but still the upward drift.
I then remembered that on the Paramount MEII in the dome I had to drift align with PHD2 to get it properly polar aligned and that PoleMaster was only good enough for short exposures or rough guiding. So I set about drift aligning.
PHD2 Drift Alignment
The first thing to note is that the polar alignment was out by a fair bit to get the accuracy I require in both azimuth and altitude. I have now adjusted both and the graph seems a lot smoother.
So in all it took me around 1 hour to drift align and just as I was about to test the clouds rolled in!
Tonight I wanted to continue to try and get guiding working, I setup outside on a much calmer night, no real wind tonight. Bob once again is playing with the IMT3.
I setup in the same place on the patio and again fed the USB cable through the window. I used the Polemaster to get the mount in the right position and then slewed to Betelgeuse to see if it was in the centre and it was!
I then slewed to M35 and connected the guider with PHD2. After some back and forth I got it calibrated but it was complaining about the amount of steps being to small for calibration and the guiding was all over the place. The screen brightness was still very white. I solved this by changing the Gain for the camera.
I decided to give TheSky X a go at guiding instead of PHD2. Unfortunatly it was not much better and at one point I could see the downloaded image from the guider then suddenly it disappeared, I had changed nothing but now it was black. Nothing I could do would make it come back including disconnecting. So I went back to PHD2.
I managed to fix the issue in PHD on the amount of Steps being used to calibrate by adjusting the calibration step size down from 5333 to 1300. This increased the steps from 3 to 5. Much better and now I don’t get the error.
PHD2 good calibration
However right now I still cannot get the Dec to behave. Whilst I can take a 5 min image the Dec is wonder up from where it should be and no amount of tweaking the Aggressiveness or Hysteresis changes that.
Furthermore, I decided to take images with The Sky X over EzCap but after 4 images TSX hangs every time……. So I have now given up tonight and will come back out the next cleanser night to resolve the issues.
First time out for a very long time with the travel setup. I need to get the guiding working before the Tenerife holiday in July. I have left Bob to play with the IMT3 whilst I work through the bugs.
The challenge is at first remembering how to set everything up. I found after some effort I was actually missing a cable, it was in the black wheelie case in the garage with the laptop tent and scope daytime cover, but more about that later.
So So after finding a place on the patio where I could feed the USB cable through the Orangery window, I put the Berlebach tripod down and placed the MyT mount on top. I tightened the screws and then placed the Sky-Watcher Esprit 120 ED on top of the Versa Plate. Once in position I balanced the scope then connected the various cables, now all through the mount due to my good friend Bob making up some power connectors for me.
So I tried to guide through PHD2. There was a large wind blowing. On trying to calibrate the scope would not move. After what seemed like an hour I remembered that cable, this was again the ST4 guider cable that is needed on the Mac if you are guiding with PHD2 as there is no ASCOM. So I connected the ST4 cable and it worked.
What I could not achieve tonight was to get the guide graph behaving, it was a mess. The wind was at fault but still there were other issues, not least the slider to control the contrast of the screen was causing anything above 0.5s to become white.
Guiding a mess with PHD2
After many hours I gave up and brought the rig in. I had been using TheSkyX to slew there scope, PHD2 to guide and EzCap to connect to the QHY168C camera and take images. I will try again tomorrow night.
This evening started with the Moon high in the sky and waxing its way to half. Next to it Saturn sat, close in fact, so close I pointed the scope at it, around 22:30 and both the Moon and Saturn fit in the same field of view 🙂
So I took a few exposures, worried that either the Moon would be overexposed or Saturn underexposed. I settled on 0.001s and took a bunch of shots. Below is my setup by the light of my rather bright head torch, turned on only for this photo I might add.
Esprit 120 and MyT
Next it was back to trying to resolve the guiding issues that had troubled me the night before. The good news was Tom from the Software Bisque website (not the Tom Bisque, another Tom) had come back with a few suggestions and questions that made me think. I had a good set of guide stars to choose from.
Hw many guide stars!
The autoguide Setup window is where I would spend most of my time I was sure, changing parameters.
Guider settings
I recalibrated the mount, this time using 100arcsec as the parameter. The previous calibration run produced a rather short cross.
Poor calibration ?
This gave me a better ‘cross’ and I think should improve the guiding, although I am still skeptical about just how quick it calibrates, some 4-5 seconds.
Better calibration
Back to guiding the mount was still all over the place, I am convinced it is overcorrecting, on the basis if I don’t guide I get better stars up to 45s or so. I added in a much longer settle period and this seemed to help, but still the graph is a long way from the sort of guiding I was getting before they updated the software.
Poor guiding
The wind was a bit gusty tonight as last night and for sure this was not helping, you can tell from a few exposures it was wind related jumps and drifting
I sat back after a while of changing different settings feeling that it was not improving, so I took a whole bunch of images, only 90s of the Sharpless object Trevor had mentioned, SH2-101 which is called the Tulip nebula. Trevor had produced a lovely image from his 14″ in the UK so I thought I would have a quick go, knowing most of the frames would be lost.
Final set of guider settings
So by 00:30 I decided to start to pack up, the wind had picked up, I was cold, the guiding was still a problem, so by just gone 1am I was heading down the mountain, some 1 hour and 20min drive! The final view from the bridge as it were was this.
View from TSX
The next day I processed the data for the Sharpless object and it was ok, given the short amount of data. One for the 12″ I think.
SH2-101 Tulip Nebula
Meanwhile I processed a single image of the Moon and Saturn and was pleased with the result as seen above. Here is a version with Saturn as an insert.
After a full day of all three geeks making more changes to the observatory, I setup my travel scope, Esprit 120 to get some more time logged before taking it on any serious holiday.
Before starting I thought I would record, compute and apply a Periodic Error Correction (PEC) model to the MyT mount similar to doing the one on the MEII earlier. Recording it was fairly straightforward using TheSkyX (TSX), connecting to my camera and then continuously recording the output to a log which you then read in and apply. Even though the log looked pretty terrible a periodic curve was able to be computed and looked a good fit and represented a peak to peak error of +/- 0.5 arcsecs.
Connecting the camera to PHD2 though was somewhat of a challenge, I managed to guide in DEC but the RA was wildly out even though I tried a few different settings for the aggressiveness and Hysteresis which is the previous adjustment percentage to apply as well.
When trying to image with this sort of guide graph from PHD2 the resulting image is trailed. Note the greenness of the image is due to the bayer matrix array of the camera being RGGB and thus 50% of the light is in the green and would be corrected later. The picture below is a zoomed in portion of that image.
So instead I moved to TSX to see if it would guide any better, knowing full well that PHD2 should be able to do this if I could get the right settings. In TSX I took the default values and then choose a guide star and started guiding. The output is fairly similar to PHD2 in the graph and immediately the RA error again could be seen and the resulting trailing of the image taken with EZCAP on the Mac apparent.
At this point I changed the settings for the guiding in TSX noting that the calibration was really quick, almost too quick, with a single move of the scope in either axis which is not enough. So I changed the calibration distance for both axis from 100 pixels to 200 pixels, I also changed the Minimum and Maximum move figures from 0.01 arcsecs and 10 arcsecs to 1 and 2 arcsecs respectively. Finally I added a delay after correct of 2 seconds.
I then started guiding again to look at the results. The new set of data was promising with the RA axis having a lot less correction needed and the scatter graph (to the right) being a tighter set of points which is good and requiring less correction.
Well that was enough tonight and I was pleased with a bit more work being completed on the scope so as the clouds rolled in I packed up and went to bed.
