Blog – Page 3 – IMT3b Observatory

Autoguider Troubleshooting 12″ OS

8th April 2023

After a successful morning of Luke helping me rewire the 12″ due to the removal of all computers apart from the Mac Mini, I looked at why the guider kept disconnecting last night and then not calibrating. It transpired to be the length of the USB run. I was hoping through 3 hubs and many meters of cable. On replacing the cable with a shorter one and plugging it into a single hub, the connection error went away. The only thing left to do was test auto guiding at night.

So roll on evening and I went out early to catch the first starts. Luke and I had replaced the All Sky Camera during the day so we wanted to see what that looked like, It is fair to say the ZWO ASI178MC is an amazing upgrade to the rubbish little ZWO ASI120MC I had been using.

New ASC with wider lens

So after much messing about with trying a camera other than the SX Lodestar, trying several pieces of software including PHD2 that I could not get working, I settled on TSX for guiding and managed to get it calibrated. On swapping the side of the mount and recalibrating I had a similar problem, however I think the brightness of the guidestar, along with the exposure time and the order I was doing things in had caused the issue.

Below are the settings used for the working system, note the calibration distance is 30 arcsecs which is fine if you calibrate on a star rather than a hot pixel.

Relay Settings including Direct Guide! 30 arc seconds for calibration distance

Successful calibration East side of mount

Successful calibration West side of mount

Guide Target Method

Settings

X2 Plugin and remove hot pixels

Autoguide tab – long exposure and subframe selected

more settings

Final settings

Success!

So you must select a bright enough star.

You must put a subframe round it.

You must them expose on that subframe.

You must then calibrate that subframe.

Viewing Report 4th April 2023

18:20 – 03:00

Before sunset I wanted to reset the dome parameters in TSX as these had got corrupted since loosing the NUC. I now have a set of working settings.

So I have managed to get the dome rotation working. The settings can be seen here for the OS12 and are documented for the other 2 scopes which are piggybacked in my TOSA manual.

OS 12″ Dome Settings

Skywatcher 120 Esprit Dome Settings

Skywatcher 5″ Dome Settings

Serial Device used for Dome

Unfortunately the night did not produce any images as the last thing I could not get working was guiding, I will take and look tomorrow. The main problem was I could get TSX, PHD2 or a 3rd party piece of software to calibrate the guider.

Viewing report 8th & 9th March 2023 Tenerife Los Gigantes Villa

Between 9pm and 12:30am both nights

A week with the family in Tenerife afforded me the opportunity to test out for the 2nd time this year the Skywatcher 100 Esprit on the AM5 harmonic mount with the ASIAIR in control and the ASI2600MC with a new Antlia Triband RGB Ultra filter.

Over the period of the week I picked 2 nights when I wanted to observe. Because of the clement environment of Tenerife and the Canaries and unlike the UK, you can decide when to go out and image as almost all nights are clear, the weather warm, around 22 deg Celsius and the bed not that far away from the pool. Given when we were on holiday which was decided around other activities, the Moon phase was Full.

The one problem with renting a villa is when the owners will not pinpoint where on a map it is. There is normally a reason. In this case it was because of the proximity of the local sports buildings. A swimming pool to the front of the villa including a floodlit pitch and 2 more flood lit pitches to the left and right of the villa at the rear.

So yes it was bright, very bright, as can be seen on the villa party wall.

So given all that light pollution I was then pleasantly surprised how well the final image came out of the singular target I chose. NGC 2244, the Rosette Nebula.

I exposed for some 75 x 300s over the 2 nights. All the images were on the West side of the Meridian to make it easier without a flip.

I found stacking 75 images instead of just the first night of 30+ images gave a much smoother background and nebula, much less noise and easier to work with the data.

So not a bad photo for Full Moon and 3 flood lit pitches. I look forward to testing out the kit at the top of the mountain later in the year under New Moon dark skies.

Viewing report & Filter Comparison 8th March 10pm 2023

I wanted to compare 2 filters this evening as I have recently purchased the new Antlia Triband RGB Ultra filter. The original filter I had for the one shot colour was the ZWO Duo-Band filter.

As can be seen above the difference without a filter is quite dramatic (Top – No Filter, Middle – Antlia Triband RGB Ultra, Bottom – ZWO Duo-Band). There is more broadband light captured. The red nebula is less apparent and the background sky is much brighter.

The above image from the running man nebula, NGC 1977 demonstrates that without a filter a reflection nebula comes through best (Left – No Filter, Middle – Antlia Triband RGB Ultra, Right – ZWO Duo-Band). The ZWO filter gives a more green image over that of the Antila, which in itself reduces the reflection nebula but does start to pick up some of the red emission nebula within the Running Man.

The inverted background above gives a sense of the reduction in star luminance that is allowed through without a filter.

This image shows the background with the details of the readout from each of the pixel across the colour channels. Here you get a sense of the green seen in the ZWO filter is less the extra green coming through, moreover the lack of blue being allowed through. Without a filter the background sky is swamped with all colour channels.

With no filter the full effect can be seen above, much brighter background, nebula less colourful and less detailed.

With the Antlia filter above, the final single image I personally find is much more pleasing.

Finally with the ZWO filter you can see quite clearly the green effect.

So in summary I would say the ZWO filter is better than no filter except when imaging reflection nebula, however the best filter is the Antlia filter when paired with my one shot colour ZWO ASI2600MC camera.

Below is a random drawing of a scientist with a Tak laser beam.

Venus & Jupiter Conjunction (02/03/2023)

At 18:15 I decided to grab the SkyWatcher Heritage 150 baby Dobsonian and setup it up in the back garden to view the Moon and the conjunction of Venus & Jupiter that were following the setting Sun in the West.

My neighbour saw us in the garden and asked if he could pop over and take a peek. In the 25mm eyepiece we could fit Venus and Jupiter in the same field of view. Venus was way too bright for me to see the slight phase (85.5%) but with Jupiter the two main belts and three moons were clearly visible. In the 10mm we could make out the main four moons with ease.

Moving to the Moon we used both the 25mm and 10mm eyepieces to view the craters on the shadow terminator. We tried to grab a mobile phone picture but the baby Dob really isn’t up to the task and all attempts were disappointing.

Using the Televue x3 barlow and the 10mm we could see craters in the shadow terminator nicely along with Clavus and the craters within.

10mm & 3x Barlow simulated view (Credit Stellarium)

Although the baby dob is great for grab and go I feel that SW 8-inch Dobsonian with a really good eyepiece would have done Jupiter more justice but hey the views were good enough and the experience enjoyable.

Viewing report 24th February 10pm 2023

22:00 – 01:00

Tonight was all about further testing of the travel scope which is now the Esprit 100 refractor. M78 would be the target along with a quick peak at Comet C2022 E3.

Moving to the Comet and having a quick look I could see how green it was and the the stars were very sharp.

I then slewed to M78 and took a single 600s exposure, however I remembered I had the ZWO Duo-Based filter left in so the reflection nebula is not very apparent, whilst part of the Orion molecular cloud can be seen clearly to the upper right.

So overall a good evening testing the equipment and ready for another trip to Tenerife in March.

Baader UFC, QHY OAG-M and QHY268C

My current setup for OSC on the Takahashi FSQ-85 uses the QHY-OAG-M and the various QHY metal spacers which you screw through the OAG onto the CAA that fronts the QHY286C.

However, I’ve never liked the screw adapter approach for this sensor as unnecessary back focus is wasted due to the weird CAA to QHY286C not being a screw thread. The lack of an IR cut window on the QHY268C sensor means I need to sit an additional filter in the QHY 020055 M48 (F) adapter, in order to change the filter I would have to take the imaging train apart to remove it !!!

Baader Universal Filter Changer

Enter the Baader Universal Filter Changer (UFC) , the chart below details the core base changer alongside the adapters required to match to most common setups.

You can purchase additional sliders than can hold 50mm, unmounted and threaded 2 inch (M48) filter. The slider is magnetic so it will not dislodge during slews or during scope assembly or disassembly.

The 4 assembled components of the Baader UFC

Proposed Set-up

The Takahashi Flattener (TKA37582) has a metal back focus distance of ~56.2 mm so I need to get close to that but being under that distance is better than being over as I can add additional spacers if needed. The effect of adding a 2mm thick 2-inch filter decreases the optical backfocus by 0.6mm (2mm/3) so I will need to add 0.6mm spacing to account for the filter effect which results in a total distance of ~56.7mm.

Order	Component	Thickness (mm)
1	QHYCCD QHY268C CMOS	17.5
2	QHYCCD CAA M54(f) (#020002)	6
3	Baader UFC M54(m) camera side adapter (#2459117)	2
4	Baader UFC base (#2459110)	13
5	Baader UFC SP54(m) telescope side adapter (#2459134)	1
6	QHYCCD OAG-M M54(f) (#020079) adapter	3
7	M54 Metal Spacer	0.5
8	QHYCCD OAG-M	10
9	QHYCCD Metal Spacer	0.4
10	QHYCCD OAG-M M54(f) adapter	3
11	M54 Metal Spacer	0.3
12	Baader M54 x 0,75 Inverter Ring	0
Total		56.7mm

I should now be able to change filters much easily albeit at an additional cost but the flexibility should be worth it. Of course I will need to test the star shapes in the field to make sure that I have the correct back focus and add extra distance if needed.

Vendors

The majority of the Baader UFC components were purchased from FLO (First Light Optics) and the remaining adapter (#2459134) from Tring Astronomy. Delivery and communication by both vendors was great, shame about the Royal Mail industrial action messing deliveries about during the Christmas holiday.

Thanks

My gratitude to Stuart1971 from StargazersLounge who helped me with suggestions to try to sort out the QHY268C noise banding issues.

PixInsight – Noise & BlurXTerminator plugins

Introduction

Two plugins I have recently been using are the NoiseXTerminator and BlurXTerminator written by Russell Croman and available from the RC-Astro website.

The new BlurXTerminator plugin is priced at $99.95 although you will get a $10 discount if you already own other RC Astro products and provide the license key at purchase time. Before purchasing it is suggested that you should first check the web site that your hardware and OS meet the requirements to function and download the trial version to test.

The data used was 60*300seconds (5 hours) frames at -20℃ of the Iris Nebula (NGC7023) captured at the IMT3 dark site using a NEQ6 mount, Takahashi FSQ85, Tak Flattener, QHY OAG and QHY268C CMOS camera.

NoiseXTerminator

Recommended Usage

Taken directly from the web site :

NoiseXTerminator can be used at any point in your processing flow. The PixInsight version can handle both linear and nonlinear (stretched) images.
Using NoiseXTerminator on images that have already been heavily processed, particularly with other noise reduction/sharpening software, can produce less than optimal results.
If processing a linear (unstretched) image in PixInsight:
- Make sure PixInsight is configured to use 24-bit STF lookup tables. Otherwise you might see what looks like posterization in your image, when it is really just limitations of the lower-precision default lookup tables.
- In PixInsight, you can create a preview containing a representative sample of your image, including bright and dark regions, important detail, etc. Select this preview and run NoiseXTerminator on it to allow rapid adjustment of the parameters.

Before & After Comparison

It’s clear that the noise reduction plugin has done a great job although it would have been better had I collected more data to increase the SNR in the first place !

BlurXTerminator

Recently released in December 2022, I thought I would give this plugin a try as I’m rubbish at all the deconvolution/sharpening attempts and I tend to make my images poorer rather than better !

The web page states the following – BlurXTerminator can additionally correct for other aberrations present in an image in limited amounts. Among those currently comprehended for most instruments are:

Guiding errors
Astigmatism
Primary and secondary coma
Chromatic aberration (color fringing)
Varying star diameter (FWHM) and halos in each color channel

Before & After Comparison

The central part of image before BlurXterminator

The central part of the image after BlurXterminator

Again we can see that the RC Astro BlurXterminator has done a good job at sharpening the detail in the dust cloud.

Thoughts

Investing in these two plugins should be considered as money well spent especially when it can save you time in the processing pipeline. The minimally processed image (DBE, SCNR) of NGC7023 (Iris Nebula) where hot pixels and other artifacts still exist but is shown to demonstrate the power of Noise and BlurXterminator :

Imaging Report 15th-16th December 2022

As it was a work night and Dave was working I was imaging from the back garden and not the dark site. I started late in the evening and had issues sorting out the autofocus in NINA which meant I was even later than I had planned.

Using the OptoLong L-Pro filter and the native camera driver (not ASCOM) :

The target was decided by Dave as M31 (Andromeda Galaxy), I decided on 120 second exposures at -15℃, gain 0 and offset 30 (Photographic Mode). I finally started to capture data at 19:55 when M31 had already transited 45 minutes earlier.

M31 single sub (stretched) via NINA Imaging Session

I believe the dark shadow to the left is the QHY OAG prism, I may have to reduce it’s depth in the light path or rotate it 45 degrees so it sits on the long horizontal axis.

Once M31 had reached approximately 50 degrees altitude and was starting to set in the West my guiding started going awry especially in RA. I put this done to either balance issues or cable snagging so that’s something I need to look at in the future.

After shutting down earlier than I thought due to the guiding issue and the pending rising Moon I decided to do my darks, flats and dark flats. However my Pegasus Flatmaster refused to connect to NINA so I decided to fix and complete this task on a different day.

I only managed to capture 62 subs which totals just over 2 hours. I was hoping to get at least 6 hrs for a single session and something approaching > 12 hours which means I will need several more nights to capture my required amount of data for M31.

Not a great first outing but given I hadn’t imaged in ages this was expected. I can honestly say that although a OSC coupled with the new harmonic mounts such as the ZWO AM5/Pegasus Nyx are very convenient as part of a lightweight holiday travel setup. OSC also is easier processing but still I can say I’m not a total fan due to the loss of high frequency data, high HFR focus issues and in the case of the QHY268C the noise banding issue which although appears to be removed by darks etc still is unnerving.

Update (17/12/2022)

Have resolved my Flatmaster 120 panel issues but I feel I’m better off with a fully controllable fixed panel instead of a manual panel so I will look into that.

My Darks, Flats and Dark Flats are now done (25 of each) all performed at -15℃ to match this session temperatures but there is still not enough actual data to start processing.

Equipment Check-up

So after ages I’m planning to perform some imaging after being challenged by Dave to produce a OSC image of M31 with the QHY268C that can be of print quality.

The first step was upgrading all the necessary software to make sure both the NUC and laptop would not be interrupted during my planned imaging session.

Windows10 latest Updates (Dec2022)
SGPro (4.2.0936)
NINA (2.1 HF1 Beta002)
ASTAP (2022.12.09)
ASCOM (6.6SP1)
Pegasus Ultimate PowerBox (1.6.1230.46)
iOptron commander (5.9.0.2)

The iOptron CEM60 mount hadn’t been updated in ages and it showed :

HandControllerV2 : 210106
MainBoard : 190716
RA board : 201005
DEC board : 190716

After performing the firmware update procedure, the mount was now showing the following levels :

HandControllerV2 : 220119
MainBoard : 211018
RA board : 211018
DEC board : 211018
Catalog : 150429

Of course I will need to perform a new zero mount position following the upgrade. Tonight I will also be changing the OpenPHD algorithm to PredictivePEC as described by Cuiv the LazyGeek :

https://www.youtube.com/watch?v=BfvmlR3It1o

Viewing Report 10th December 2022

23:00 – 00:20

So it’s about time I tried to find a replacement for SGPro, given the continued problems with it, it’s less than intuitive design and find something that does not cause friction in my desire to capture more photons from the distant universe! So after looking at NINA briefly earlier this year, I have gone for it this evening to see if I can indeed capture some images.

The problem that set me back once before with NINA was the lack of connection to the FLI focuser. I just simply got an ASCOM error (I really dislike ASCOM). So after some educated guessing I got it connected. Instead of connecting to the FLI focuser directly I actually went through ASCOM which bizarrely cured the error.

With that done. I could now run autofocus, and only the 2nd time in my life this astronomy programme focused on the first go. The only other piece of software that good is the ZWO ASIAIR that I really enjoy because it just works.

I have now connected NINA to PHD2, also to TSX and left TSX to control the dome. I may change this later, however it works just fine and has not caused any problems. The only reason may be to further automate the dome for closing and reporting on status if that is a feature of NINA, something to look into later.

Managed to take 5 or 6 Ha images of 600s this evening before the cloud rolled in. I can use the flats from yesterday. A good evening testing given conditions including the almost full but waining Moon.

Viewing Report 9th December 2022

19:01 – 03:05

Dome open on the freezing night, currently -2℃, and I have fixed the dome slipping for the 2nd time this week, this time putting new grip tape on a hole that had appeared due to the wheel slipping.

Started out imaging M76 which is near the Zenith whilst we watch Harry Potter in the warmth of the lounge buy a roaring fire. After 11 frames of 600s in OIII I have stopped and slewed through Meridian flip and now started on Ha as I have 84 frames of OIII already……

So at 1:15pm I had 23 x 600s Ha on M76. Whilst I need much more and then RGB frames, I want to go to bed and M76 will set shortly to a less than desirable altitude. So I took my flats, darks and flats darks and closed the dome up for the night as the Moon was still fairly full.

Viewing Report 8th December 2022

19:43 – 22:29

For a long while I have had the observatory turned off. All the computers, mount and dome, due to the energy crisis. However, tonight I wanted to make sure the dome still worked and I could image an object so I turned most things back on. There are some things I can do without, including the ASC.

I managed to fight with SGPro to get it to image and slewed to the Soul Nebula. In particular a star galled GSC 4048:1298 which is near a nice Ha region. I found a guide star through the off axis guider and set about imaging 600s subs. I took around 7 before the dome closed due to the moon being so bright the weather statin reported it being too light to image! So the dome closed. I did reopen and get some more data but now it is too late and I need some sleep for work.

I took flats, darks and flat darks.

Viewing Report 24th September 2022

23:45 – 01:43

Another go at Jupiter tonight. The jet stream from netweather.tv is out of the way. I got really good focus. I managed to use the atmospheric dispersion corrector and get good alignment of the channels. I then took a mixture of 90s and 120s movies. I stacked in Siril and process in PI all on the Mac. So seeing has been my real problem.

Ganymede, Jupiter and Europa (left to right)

Viewing Report 18th September 2022

21:00 – 02:20

GingerGeek came over again and we setup on the patio. I then waited for the clouds to clear at 12:30am before I had 45 mins to capture Jupiter on the Mak180 without the barlow. The jet stream (https://www.netweather.tv/charts-and-data/jetstream) was much better tonight so I could get better focus and the detail on the planet looks better with glimpses of the moons showing.

Viewing Report 16th September 2022

18:45 – 03:38

Imaged Jupiter all night. The last few videos were with the barlow out.

Finished imaging around 03:38, the humidity had got very bad, around 90%

GingerGeek joined me

Viewing Report 27th August 2022

21:49 – 23:32

Not entirely clear this Bank Holiday weekend, however good enough to test out the newly cleaned ASI1600MM with the new desiccant. I received the desiccant from Zoltan at Astronomy365 and cooked in the microwave for 2 mins on medium power before letting cool down and then placing in the camera. I managed to get most of the dust off the sensor, however it is very difficult.

At 00:15 I started to image M72 the globular cluster low down in Aquarius using LRGB 60s on Luminance and 300s on RGB. Note that I will need all new flats today due to the cleaning of the camera. I will leave the observatory running overnight and head off to bed.

Update from this morning, looks like the observatory run all night without a problem and however I believe the object went behind the trees in the distance that have grown after about 10 luminance frame 🙁 I took flats this morning and will take darks tonight.

Flats – Done

Darks – Not done

Viewing Report 20th August 2022

20:36 – 00:39

Back for a second night tonight. M26 is the target again to get some more quality data on the open cluster.

I will set the camera back to Gain 10 Offset 10 to allow for maximum exposure with minimum star saturation. I have had some cloud this evening so far which caused the dome to close. Now it has cleared I have reopened.

Focus run at 22:04 gave 15,965 on Luminance. I left the observatory running at around 12:30am and headed off for bed.

I noticed in the morning the dome had closed and the imaging stopped 40 mins before completion. There may have been clouds so I will check the rest of the frames later. I should have then refocused again later as it drifted again. I reviewed the LRGB frames however the guiding was not brilliant and some of the frames have trailed. I took Flats and Darks in the morning for completeness.

Viewing Report 19th August 2022

22:43 – 03:06

First tonight was to take some 300s darks for the other night for NGC 6765. I only needed 5 of them so spent the first half hour on that.

Then looking at what I could do before the Moon comes up around 11:30pm, I have a couple Messier objects on my list to go after. M26 is the initial one to tackle. I will try a low exposure for luminance and longer on RGB.

Initial focus position is 17,782 for Luminance. I then had to take a new set of darks for the Lodestar camera. I am not sure why these no longer match.

@ 23:53 I started imaging M26 LRGB, L = 60s, RGB = 300s

Focus run at 1:06am 16,879 for Luminance

Finished imaging just before 2am when the object was too low and the bottom of the dome slit was in the way. I then went on to grab flats and darks.

Viewing Report 7th August 2022

22:30 – 02:37

Tonight John Barrie-Smith and Bob came round to observe with me from Mirador Ellisfield. The temperature has been warm +24c and the humidity average. I assembled the 22″ dob and brought out the 100mm binos.

Bob had a pair of tiny binoculars which whilst we were waiting for darkness to arrive we thought we would try them out. To our surprise when looking at the Moon we could see a star to the East which transpired to DSschubba, a mag +2.2 star in the constellation of Scorpius. This is top star above Antares in the scorpion. This was unseen with the naked eye.

We then realised that the Moon was going to occult this star and that we could watch it happen. So with Bob on the Binos, JBS on the 22″ and I with my Canon 6D with the 300mm lens, we set about watching the event.

We caught the star being occulted by the Moon, but then we struggled as the Moon was setting behind the trees in the distant forest. However around 22:13:20 the star reappeared just as the Moon was setting around +4 degrees altitude. A good result!

Moon setting with the star hidden behind

So after a thrilling and unexpected chase, we set about using the 22″ for some visual. I had started SkyTools 4 for the first time earlier in the day and created my first observing chart. I printed a list of objects to go after and we used this to work through some very appealing and easy targets.

M21 was seen by JBS and I before it quickly set behind a tree, however this open cluster looked great.

M102 was easy to see with direct vision. This galaxy looked splendid through the 13mm Ethos eyepiece. This was a long thin galaxy with a slight bulge to the centre. Whilst SkyTools did state the 24mm Panoptic was the best eyepiece to see this with, we felt that the 13mm Ethos was a good option and provided the best view.

John then wanted to go to M101 the Pinwheel galaxy. This is a face on spiral that has a low surface brightness and was rather hard to see. We tried all 3 eyepieces, so the 24mm Panoptic, 13mm Ethos and 31mm Nagler. To prove that this was because it was a harder object to see with relatively low surface brightness and thus did not appear on my SkyTools list of Easy and Obvious objects to see, we set about looking for M51 with it’s associated NGC NGC 5195 interacting galaxy. This was as we noted fairly faint to see also but rather distinct with the 2 objects being visible.

We also looked at an open cluster called the Cooling Tower, M29 or NGC 6913, Bob could see the cooling tower in this little cluster of stars which was bedded into the Milkyway’s rich star field.

We then looked at the Blue Flash nebula, NGC 6905 which did indeed resemble a flash in the pan of oil.

We then went to M5 a glob that was very low down and did appear on the list. The scope was all but horizontal but provided a good view despite the seeing.

Finally we stole a look at M13 which was to compare with M5 and wow it was really bright and steady and the details of the stars within especially with the 13mm Ethos were amazing. It is worth noting that it was fairly high in the sky unlike M5.

Once Bob and JBS packed up and went home around 12:30am I slewed the 12″ in the dome to NGC 6905 the Blue Flash and too a single 2 min Luminance exposure to see what we had seen.

I then loaded my sequence for NGC 6765 and took a set of LRGB and OIII 300s exposures, x 5 each until 3:45am. I left the scope running until morning and went to bed at 2am. A really good night with friends.