My Journey into the world of astro-photography

My journey into exploring the night sky started in the middle of the COVID lockdown in  2020. I had read an article on the web about a Newtonian telescope (Pikon) that used a raspberry pi camera instead of having a secondary mirror and eyepiece. At the time I was looking for a project to use my raspberry pi on, and this seemed to fit the bill.

A couple of months later, using a ventilation pipe for the OTA and after much 3D printing, it was up and running and attached to a spotting scope tripod. I managed to get a few images of the moon and my interest into looking at the night sky took me along the route of doing a couple of the Open University courses in astronomy. One of these courses involved using their telescope in Tenerife.  My first image was of the Orion nebula. I was hooked on astrophotography.

The difficulty I encountered with my Pikon home made telescope was tracking. I did not realise just how fast the earth rotated. The solution was to motorise the telescope. After lots of 3D printing and electronics building using a OnStep controller it was ready to work as an Alt-Az  goto. It even had a motorised rotator controlled by the OnStep  software. Along with a another raspberry pi and a wifi link it worked from a technical viewpoint and I could control the telescope inside the house on my pc through Astroberry using Kstars, Ekos and Indie and imaging using RPI camera. The mechanics however let me down with far too much play in the plastic gears as well as being too fragile to be of any real use.

My solution to a flimsy home built telescope was to buy a second-hand Orion Europa 150mm Newtonian on a EQ4 mount. Some more 3D printing,  a faster OnStep controller build, and an  auto focusing motor attachment,  brought me to a position where I had an operational EQ goto set-up. I had also built an OnStep hand control that allowed me the option of controlling everything at the telescope in addition to indoor pc control. The tracking was still not as precise as it could be  so a finder scope  and a raspberry pi camera was added as a  solution for guiding, but I never got this guiding to work, even after changing the raspberry pi camera to a Zwo Asi120MM. This set up did work, apart from the guiding, but I became frustrated at the length of time it took to get centred on what I wanted to see and image. I was by then using a Svbony 305 Pro camera using AstroDMX for my main imaging and the Zwo as an imaging finder scope. with a Svbony 60mm guider scope. In fact, some of my initial early image successes of the moon were using the wider field of view of this Zwo camer and the giderscope for the imaging.

I has by then realised that for me, my ideal telescope was a SCT. I was attracted to the shorter physical length of this telescope. I was torn between Meade and Celestron on a Alt-Az mount. In the end a second-hand Celestron 8SE was purchased at a good price and with the addition of a Starsense for auto alignment, an auto focus motor  and a wedge, I was there… almost.   I was using my Nikon DSLR and with focal reducer for the SCT,  as well as the Svbony camera. This gave me a reasonable range of field of views, with just the wide angle FOV missing. The Zwo ASI120 was used as a guide camera using PHD2.

I loved the ease of set up with the Celestron package and had deserted the Orion entirely. This was sold, along with some other items no longer used and I bought a second-hand Celestron AVX mount for the 8SE SCT and a Skywatcher Startravel 102. The 102was initially mounted on the Celestron Alt-Az mount with the wedge. Whilst this latter set up worked well, I realised the limitations of an  Ach v Apo telescope and an 80mm or so Apo, at some time, wiould be my final purchase.

Up to December 2022 my main set up was the Celestron 8SE or the Skywatcher 102 on the  AVX mount. I use a Microsoft Surface 3 as he processor at the telescope and VNC to control the Surface from my pc in the house. If using the 8SE I do an initial Starsense auto align initiated from the pc using Celestron PWC, whilst for the 102 I use the plate-solver in NINA. I have markings to position the mount in exactly the same place each time so no polar alignment is necessary. Once alignment is done (a couple of minutes from start) I connect everything to NINA to control the cameras, telescope, PHD2 for guiding, autofocus  and for plate-solving. The StarsenseAutoalign was subsequentlysold as I found I was not using it – NINA 3 point alignment and platesoving gave me everything I needed.

In early 2022 I decided to buy an a camera more suited to deep sky imaging and purchased a Altair 183C Pro camera, which gives me a narrower field of view than the Niken D7000. In in mid 2022 I added a Zwo Electronic Focus Wheel to the set up. I now have a choice of no filter, a broadband filter and a Trib-band filter for emission nebula.

In December 2022 I decided to sell the Svbony 305 Pro camera, the Celestron Alt-Az go to mount and wedge as they were not getting any use. It was also time to change the Skywarcher 102 Ach and replace it with an Apo. My choice was a William Optics Zenithstar 73 telescope, with a 0.8 reducer and flattener and a ZWO electronic auto-focuser (EAF). I now use both telescopes on the AVX mount, choosing which one according to the FOV for the imaging I am doing. The Surface 3 was replaced with a Beelink Mini S pc in order to reduce the power consumtion when imaging as the Surface seemed to use quite a lot of the battery capacity on a long night.

I use Sky Safari on an iPad or Stelarium on PC to plan a nights imaging and sky exploration, then set it all up in NINA using the Sky Atlas and Framing Assistant to select each image and the Advanced Sequencer to control the session for the evening starting with un-park and the initial focusing and 3 point polar alignment, slewing and centring on the images selected, plate-solving the position, auto-focusing, and then managing PHD2 guiding and camera and filter wheel control. Finally, at the end of the evening the Advanced Sequencer will park the telescope.

Initial images are recorded on the mini PC’s during the imaging session and then remotely transferred to my main home PC for stacking and post image processing. Initially this was done using Photo Affinity with the final tweaks using the iPad photo editing , but I now use PixInsight as my tool of choice for stacking using WBPP and then going on using a well established and developed workflow of Pixinsight processes and scripts, which includes BlurXTerminator, NoiseXTerminator and StatXTerminator.

Whilst I was content with what I had as a home set-up I did feel I was missing out on going to alternative and darker sites, especially when travelling with my motorhome. I have just bought a RVO Horizon 60 ED refractor and a Skywatcher Az-GTI mount (both bought secondhand) to experiment with this set up as a portable unit. Initially everything else was the same as at home with the same camera and EFW used on the 60 ED and the Beelink Mini S as the control PC. I have a Solwise small router to create a Wifi access point so that all the same software can be used to control and operate the telescope.using either the Microsoft Surface 3 or an IPad.

Initial use of this portable set up at home and the first session enabled me to achieve 300 second guided images and some reasonable results. The tripod on the Az-GTi was a little wobbly but with a 3D printed addition spreader bolted near the top of the tripod it has been transformed. I now just need to try it out away from home.

The portable rig has now been enhanced with its own guide camera (Svbony Sv905c) and gude scope (Svbony Sv165), a ZWO EAF focuser and a Beelink Mini S pc. For the main imaging camera on this rig I reverted back to my Nikon D7000 DSLR but I was able to get a secondhand astro modified Canon EOS 1300D and now use this.

To enable me to operate any 2 of the 3 telescopes whilst at home at the same time another lightweight mount was sought sufficient to handle the weight of the Williams Optics Zenithstar 73. I settled on an Explore Scientific iEXOS PMC-Eigh Equatorial mount, which I bought secondhand. This gives me a lot more options and a much wider wider range of sky views as I can use any camera with any telescope in any of the 2 viewing positions (1 northern sky and 1 southern sky) I have at home as well as having a portable option for away from home.

After some use with these various rigs I decided that the AZ-GTi was not really good enough for exposures over 60 seconds and I found the Explore Scientific mount to be very easy to carry, even fully set up, and could guide well on long exposures, so have decided that the Explore Scientific will be used as the portable set up. The Az-GTi was sold and a Skywatcher EQ5 has been acquired to be used as the mount for the ZS73 and the AVX is now used soley as the mount for the Celestron 8SCT.

The camera setup has also been changed with the purchase of a ZWO ASI585 Pro – my first cooled camera. This is now used with the 8SCT on the AVX mount (Rig 1) whilst the Altair 183C is used with the ZS73 on the EQ5 mount (Rig 2). The Canon 1300D is now used with the Horizon 1300D on the Explore Scientific mount (Rig 3). At any time I can operate 2 rigs at the same time.

Each rig is fully set up and I have the tripod positions marked up giving me a vey quick polar alignment, basically just fine tuning. I just need to choose which rigs I want to use and this is determined by the Field Of Voew of the images I have selected to photograph. Rig 1 is 0.5 degrees FOV, Rig 2 is 2.1 degrees FOV and rig 3 is 3.5 degrees FOV. I think I am now there.

Over the period of my journey I have learned that astrophotography has a long learning process. It is about taking one step at a time, mastering that, and then moving on to the next step. The fact that there is a thriving and active second hand market for telescope equipment makes the journey affordable and most of my equipment has been bought secondhand and subsequently sold with very little loss once I had moved on to the next step. For a few items, I have even made a small profit.

I hope you like the results.