Astrophotography Rigs

Here are details of both my Astrophotography rigs. I have always found that pictures of other peoples setups have been most helpful when setting my own up, they gave me lots of ideas so I am happy to share mine (and take tips!).

I have two Astrophotography rigs, Rig 1 is narrow field of view setup which I use it at home only (it’s 85 kg and I have multiple flights to climb!). Rig 2 is a wide Field of view and is much lighter so I can travel with it (car only!) to remote darker locations. I would love a purpose built observatory but my home location does not afford me that option so I am one of those who regularly sets up their rig.

I swop my camera train between the two rigs, its a ZWO ASI294 mc pro which I usually cool to -10c. In the future I have my eye on a ASI6200MC Pro (when the lottery ticket comes in).

A couple of key things I always try to achieve to help with balance and guiding is weight always near the centre of gravity for the mount and balancing weight either side of the telescope. Two counterweights higher up is always better than one lower down as the payload increases.

Balancing east or west heavy depends on the rig too, my IOptron CEM60 works better completely balanced whereas the AVX prefers west heavy (from my experience).

Rig 1

This is my narrow FOV Astrophotography rig and consists of:

• IOptron CEM60 mount
• IOptron IPolar
• Celestron Edge HD 8″
• Celestron 0.7 reducer
• Celestron auto-focuser
• Dew heater straps, controller and dew shield
• My standard Camera train
• Startech USB 3 hub
• Raspberry Pi4 4gb with 64gb SD card and a 64gb removable SD card USB reader for image storage after capture.
• TP-Link TL-WR902AC Nano Router AC750

This astrophotography rig is based around an IOptron CEM60 with an IPolar fitted for easy polar alignment. As this mount can carry a high payload, I use it with my Celestron EdgeHD 8″ which was the first telescope I bought, and although it has a much higher learning curve for a beginner to get good results, once mastered, is a great piece of equipment.

I originally used it with my Celestron AVX mount but it was just too heavy for it and I never got guiding much below 1.5 rms – adequate but not good for long exposures so I do not recommend pairing them unless you are a masochist…

I also replaced the IOptron RS232 cable with a new RS232 RJ11 socket to USB direct with an integrated FTHI chipset so no need for an adapter cable – you can find these on “AliExpress” if you search.

You can see that on the front of the Edge HD I have put an ADM Dovetail Counterweight Kit as the camera train made it a bit too back-heavy and I wanted better balance for guiding.

The computer board sits atop the scope using an ADM bar and clamp kit – the board itself is a super cheap lightweight kitchen chopping board cut to size with a saw! The RPi is ethernet connected to a WiFi giving a fast reliable response using VNC on Astroberry – everything is automated that way, nothing is off mount. All the power, including to the RPi, is supplied using a StarTech 7 port USB hub, only the camera cooler takes another direct supply.

What I love…

The IOptron CEM60 has a great payload (don’t exceed 50% rule for good guiding) and stability – depending on things such as wind and seeing, I can often get to around 0.5 to 0.7 rms guiding enabling the Edge HD to really take advantage of longer exposures with its small FOV. The mount hand controller is simple to use. The CEM60 cable management is good due to USB and power ports on the mount head – less trailing cables. The IOptron IPolar is just so fast & easy to use…

The ZWO OAG works great, I have only once failed to find a guide star (solved by a little manual camera train rotation) and I do not suffer flexing as it is on the same scope which also keeps weight down. Some people have said to get the bigger prism (and more expensive)  Celestron OAG but the ZWO works well for me.

Not so sure about…

IOptron only fitted USB 2.0 sockets on the mount head – really? Why did they not make it a powered USB 3.0 hub? (On their newer mount models I think this is now fixed?) The IOptron mount, fittings and tripod pier leg white paint finish is very poor and is already shows signs of breaking down with the weather (rusting) in under one year. This rig is way too heavy to be portable unless its broken down into its components and that is a real time waster.

I hate collimating the SCT! Luckily a far away neighbour has a fridge visible in their kitchen window with a blue power light, perfect false star. Don’t tell them!

Rig 2

This is my narrow FOV Astrophotography rig and consists of:

• Celestron Advanced AVX mount
• William Optics Zenithstar 73
• William Optics Adjustable Flattener
• ZWO Electronic Auto-focuser
• My standard Camera train
• Startech USB 3 hub
• Raspberry Pi4 4gb with 64gb SD card and a 64gb removable SD card USB reader for image storage after capture.

This astrophotography rig is lightwieght too so I use my older Advanced VX Coelestron mount with it and it weighs in at only 5Kg fully loaded and is portable outside the house.

What I love…

The build quality of the William Optics Z73 is really good, perfect finishes and no complaints so far. I tried to get a RedCat 51 but these seem always out of stock and actually am really pleased I went for the Z73 instead. The setup is portable by car so i can travel easily to really dark mountain locations in the summer…

Not so sure about…

There is nothing “advanced” about the AVX mount, its painful to balance as its axes are really stiff and thus can be terrible to guide with for that reason. I have now rebuilt it with new bearings to improve its performance and removed the sticky cheap grease Celestron use, its a lot better now – I will publish a guide on this shortly to help others. I also really miss the IOptron IPolar and have to drift align usually on this rig which takes more valuable imaging time.

Camera Train

The camera train I use for both of my Astrophotography rigs consists of:

• ZWO ASI294 mc pro
• ZWO Off Axis Guider (OAG)
• ZWO ASI120 mini (guide camera)
• ZWO 1.25″ Helical Focuser
• TS Optics filter holder (can hold either 1.25″ or 2″ filters)
• Optolong UV/IR cut filter (optional as target dependant)
• Optolong Pro filter (optional as target dependant)
• Optolong L-Enhance (optional as target dependant)

I like to keep this constant between Rigs and have developed a single spacer change to ensure the back focus remains correct on either setup. Rather than use a filter wheel (not needed really for colour CMOS) I found online the TS Optics filter holder kit and bought two 1.25″ filter drawers for it for easy quick changing- guess what, the 1.25″ inserts screw out to reveal an unadvertised 2″ filter thread – that’s versatile, I like it!

The 2nd picture shows the train ready for the Edge HD 8″ with a Celestron 0.7x reducer fitted – it has the required backfocus distance of 105mm which includes the 6.5mm internal camera sensor to case distance by splitting the Celestron T-Adapter in half.

What I love…

I prefer an off axis guider (OAG) to a seperate mounted guide scope – it keeps the weight down and with the Edge HD ensures more accurate guiding as no flex issues between the guide scope and main scope. So far I have always found an adequate guide star in the prism field of view to guide on. I also think the ZWO ASI 294 is a great starter color CMOS camera, I gave up with my DSLR due to weight and noise, this is so much better and I always cool it to -10c even on hot summer nights.

Not so sure about…

I sometimes have trouble with the USB connector on my ZWO120 mini guide camera – even using the ZWO cables so am not sure how good camera female connector is.

Power Management

Used by both of my Astrophotography rigs, I have both a portable power supply and a mains powered supply for when at home with as few cables as possible for reliability and effective mount cable management. I have always wanted a Pegasus power box or similar but they are just too expensive for me so all my solutions are home-made, light weight and fit my requirements exactly.

Mains Powered

I use a 120w 10A mains transfer (below) inside a dew proof box but aired box (left), and then distribute as needed via a cigarette socket splitter, all bought on Amazon. The case is also useful to store leads in when packing away (for rain!) and works with any rig I am using along with a trusty 15m drum extension lead.

Portable battery Powered

I use a standard power tank (17AH) for mobile power but also have a long heavy duty male/female cigarette sicket lead for backup from the car should the power tank run low. As the Raspeberry Pi uses relatively very little juice, I do not have to power a laptop when out since I can access everything to check how things are running via a tablet (using VNC app).  All the software runs independently on the RPi – the beauty of automation.

Mount power management

My small rig uses a home made light-weight and cheap power box to distribute my 12v supply on the telescope itself and also powers the Raspberry Pi and the USB heating band with 5.1v using a car adapter converter easily purchased online. Its great having a switch for each piece of hardware and with only one power lead coming up to power the lot, helps keep guiding accurate with no cable snags possible. There is no problem with dew either.

As the large rig is based on an IOptron CEM60 mount, this has built-in power distribution to the mount head via standard 12v sockets so one cable gets enough 12v up there and I feed this straight into a sturdy Startech USB 7 port hub which in turn powers everything else via USB, including the Raspberry Pi (except the camera cooler and front heater which go straight to the remaining mount head 12v socket as both require a separate 12v supply and are thirsty on power). One USB 3 cable then goes from the USB hub to the RPi which deals with all data and control – power and data done!

All my power leads are home made and all the bits to make this were obtained from from China (AliExpress) very cheaply and simply soldered in with in-line (car) fuses on each switch for added protection. Total project cost about £20 and I have spares!

Top Tips!

Here are some equipment tips that I use to make things easier…

Buy a decent all year mount cover for your Astrophotography rigs – expensive but quality pays and means you can leave stuff outside and lose less imaging time. Also when you get those unexpected rain showers it means you can quickly cover your gear’s electrics and optics. I bought the best I could find at FLO and its of superior quality (and price!)

Treat yourself to a decent 5G exterior router – I bought one of these and power it using an ethernet cable as it comes with a POE adapter. I now a get very stable and long distance connection to my mount avoiding trailing ethernet cables – fab! It has 4g as well but that just doesn’t perform so well… the latest Raspberry Pi 4 models have 5g built in too…

Lifting a heavy rig can hurt your back! My IOptron rig fully loaded including the weights is 80kg and is a pain to dismantle so I bought 3 cheap 60kg furniture moving castors off Amazon (£6 each) – very cheap compared to other options but only suitable for paved pathways, not grass or steep downhill! I just slip them under each leg and away we go… You can’t leave them on because of wind and stability issues, but you knew that, didn’t you?

When you buy a cooled CMOS or CCD camera, buy a camera anti-dew kit for it if heating is not factory fitted. The cooling of the camera will attract more condensation then you think. I have wasted a few nights of imaging because the images were ruined by a mysterious blur that flat frames failed to remove, right in the center of the images!

Flat Frames – I know the T-Shirt method works and is much cheaper but I like to do them at night in the same conditions as I get a lot of humidity that may disappear after sunrise and therefore condensation may not be subtracted correctly from my images so I invested in LED flat field generators for both scopes which work really well – see here on how I use them to take Flat frames.

If you have a SCT telescope, fit Bob’s Knobs (stainless steel) on your corrector plate,  super cheap and they make collimating so much easier. The thought of using a sharp screw driver at night to adjust collimation within millimetres of the corrector plate scares me greatly, one slip and lots of tears  . By the way do collimate your scope if its off centered, it ruins your images otherwise.

On both rigs, I have cut to shape a piece of 0.5mm thick Teflon sheet to put between the mount heads and the Tripod heads on both rigs – this makes Polar alignment much easier as their is no longer any “grab” when you adjust the azimuth screws. It was really cheap to do and you can find some on Aliexpress, ebay etc.

If you are using a smaller refractor you may want to consider hunting down a DSLR dew heater (around £20) – you can get USB ones with an integrated controller that works just as well as the more expensive astronomy ones (which then require a seperate controller). The astronomy dedicated ones are really too expensive for what they are…

Its hard to find decent 12v connector leads with male to male 2.1mm x 5.5mm DC adapters – I make my own, its really easy to buy either on Amazon or direct from China (AliExpress etc) connector kits and the cable. That way they are the right length and you can repair them as needed. All you need is a soldering iron and solder. Make sure you buy the right grade cable – I use AWG18 guage as a minimum (the lower the number, the higher the rating).