My astrophotography setup
There is no exact way to do astrophotography, it all depends on the equipment you use combined with your level of knowledge in this field. I use a telescope mounted on a equatorial mount with can move around two axis(RA-axis and DEC-axis), driven by electric moters. When set up properly the RA-axis will point to a fixed point in the universe, similar to the Earths rotation axis. By doing so we can counter-act the Earths rotation by keeping a constant speed matching Earths rotation speed and thereby keep track on a object in the sky. This enable us to take longer exposures with the camera on the telescope and eliminates “star trailing” which otherwise can be seen as a long strake and not a perfect round dot. While the RA-axis enable us to follow an East-West movement of the objects in the sky, the Declination axis enables the telescope to move north-south.
This is the basic principles that I follow for doing my astronomy observations. When setting up the equipment I follow some procedures in the right order to ensure the best possible outcome and be able to have as much observation time as possible.
My astrophotography session in a particular night can be divided in the following steps:
My Equipment and software
Preperations and planning
Observation and photographing
Ending the session
Unpacking equipment and drying
My Equipment and software
In autumn 2021 I bought a Skywatcher 200PDS Newtonian with a Heq5 equatorial mount inclusive tripods. This telescope is ideal for observing galaxies and planets. For photographing nebules, I needed a smaller telescope, I have chosen the William Optics Zenithstar 61 II APO for this purpose.
Zenithstar 61 II APO refractor(61mm diameter, 360mm focal length, f/5.9)
Adjustable Flat6AIII field flattener
Skywatcher Explorer-200PDS Newtonian reflector(200mm mm diameter, 1000mm focal length, f/5)
ZWO Electronic Automatic Focuser (EAF)
Baader MPCC Mark III Coma Corrector
Skywatcher HEQ-5 Pro Synscan GO-TO Equatorial mount with tripods
Celestron Vibration Suppression pads
TS-Optics Guiding Set 50 mm Guide Scope TSL50-AG
ZWO Camera ASI 120MM Mini
ZWO ASI485MC OSC planetary camera
Canon 77D DSLR camera
Canon 450D DSLR camera
Tele Vue 4x Powermate 2 inch (magnifying lens)
ZWO ADC Atmospheric Dispersion Corrector Mark II
PegasusAstro Pocket Powerbox Advance( USB hub)
Lenovo X260 Laptop(Windows 10)
Powerbank USB - DC 12V / 16V / 19V 60W(Powersupply for Laptop)
Celestron Powertank Lithium Pro( Power for Skywatcher HEQ-5 mount)
Extra tools and equipment( lens blower, tripod absorbers etc.)
Oklop carrying and storage bags
Software installation on the Laptop
Pegasus Astro- Pocket Powerbox
Software for controlling and monitoring the USB and power box that connects camera, guide camera, electric focuser, dew heater etc.
ASCOM Platform 6.6 with ASCOM drivers for hardware devices
ASCOM stands for AStronomy Common Object Model which is open software to provide a standard interface to a range of astronomy equipment including mounts, focusers and imaging devices for Microsoft Windows.
EQMOD, this is a ASCOM driver based software utility that can configure and control my Skywatcher HEQ- Equatorial mount and other Equtorial mounts.
I use this software primarily for polar-alignment although it can be used for many other astronomy tasks. NB.- In N.I.N.A. imaging software there is also a polar alignment tool.
PHD2 Guiding 2.6
PHD2 is telescope guiding software that simplifies the process of tracking a guide star, letting you concentrate on other aspects of deep-sky imaging or spectroscopy. Easy-to-use, “push here dummy” guiding for beginners. Sophisticated guiding and analysis tools for experienced users.
Stellarium is a free open source planetarium for your computer. It shows a realistic sky in 3D, just like what you see with the naked eye, binoculars or a telescope.
N.I.N.A. Nighttime Imaging ‘N’ Astronomy 2.2
N.I.N.A. is a open-source software astrophotography suite for deep sky imaging. This software connects all your hardware and can capture data in manual mode with single exposures or run automatically in full sequences with multiply exposures.
Firecapture is a planetary image capture software for planetary cameras.
Platesolver software/Blind solver, ASTAP, All Sky Plate Solver, PlateSolve v2 and v3 with Database and catalog.
Preparations and planning
When the time has come and the night finally indicates clear weather and calm winds, you should be 100 percent ready to shoot some objects in the night sky. First of all, you should plan witch target you want to picture. I have created a list containing the most interesting targets (Galaxies, Nebula, planets, comets etc.)in advance, covering the hole year. You should also take into account if the moon is visible for that particularly night. The moon light can be extremely dominant and reduce the picture quality when shooting nearby Deep sky objects. It is possible though, to add special filters in front of the camera that blocks the wavelengths from the reflecting light of the moon and other unwanted light.
Thorough planning is more vital if you need to set your equipment up on a remote location versus in your own backyard. I use a nearby location so every time I have to set up all of my equipment. It is crucial to remember to charge the batteries needed to power the telescope mount, laptops, head lamp etc.
Also remember to collimate the telescope if you are using a Newtonian reflector like I am. The Refractor type does not need this adjustment.
When arriving on the spot I find a place with the best View and if possible shielded from any wind. I also make sure that I have a clear view to my targets with no obstructions in the path. With the headlamp turned on I begin to unpack my equipment, at this point I stick to my normal workflow.
Final assembly and Calibrations
The first thing you need to do is ensure that the tripods is facing true north, I use the compass in my iPhone. When all the telescope equipment are assembled and ready, the telescope needs to be in balance on the mount, this ensure smooth movement in all axis and reduce load on the gears and motors. By now the telescope have cooled or reached ambient temperature, this is important to obtain a clear end sharp picture trough the mirrors/lenses. I check the collimation( Newtonians only) and fine adjust if necessary with my collimation tool.
I turn on the power, this is done by switching on the Battery pack which acts as the main 12V DC power supply for all the equipment except for the PC, and ensure all electrical components is working ( Dew heaters, camera etc.) I connect the USB cable to the Laptop witch is controlling the telescope throughout the hole session.
Polar align the telescope correctly with Earth’s rotation axis by makeing sure the guide camera and guide scope are in focus and able to se (and later track) the stars.
I then need to focus the main telescope by adjusting the focuser knob to get the stars sharp, by doing that you will be able to platesolve and orient the telescope to a specific point in the sky, and later in the session to get the sharpest pictures.
I am now ready to start up my Laptop!
When the Laptop bots up and Windows 10 starts, I launch the Pegasus Astro- Pocket Powerbox application and this connects the Laptop to the Powerbox which I have placed physically on the telescope-mount.
Next I open the PHD2 application and connect the mount and guider. This opens the EQMOD software utility that connects to the mount allowing me to control the mount without a hand controller. This software also controls the guiding and sends guiding correction to the mount.
Now its time to “Polar Align” the mount/Telescope. I launch SharpCap and select the polaralignment tool from the menu. After following the adjustment procedure in the application, the Telescope-mount is now inside limit( good/Excellent )and polar aligned.
Lastly I launch N.I.N.A. This is the software I use for capturing my images.
I also use Stellarium, is nice to have, it shows the night sky and its objects presented in high graphical quality. This software can also show in which direction the telescope is pointing and allows you to move it between different objects.
Observation and photographing
N.I.N.A. is now opened and I load my hardware profile (Eg. 200PDS/Z61 and Canon Eos/Zwo 485). I then connect alle hardware units( camera, auto-focuser, Telescope, guider).
So first things first, at this point I need to focus the camera either with the auto-focuser or manually and by using a Bahtinov mask. This is done most efficient by pointing the telescope at a bright star. I start out by manually turn the focuser wheel/run manual autofocus to a close enough focus point where the platesolver software is able to recognize the stars and orient the mount and telescope. Adjust now from this coarse condition to fine adjustment with autofocus module in N.I.N.A. or by using the Bahtinov mask as mentioned earlier. When this process is done and the stars look pin sharp and crispy its time to test the mount/telescope/software and make sure that it knows exactly where it is and is able to point to the objects that you select. This is focus adjustment and plate-solving.
Now that we have north aligned the telescope/mount(earlier) and are able to navigate in the universe( go-to by platesolving) we need to make sure that the telescope/mount can autoguide by tracking a star or several stars. When the stars tend to drift and this is detected by the guidescope/PHD2 an error correction signal is sent to the mount, thereby commanding it in the right direction keeping the stars and object fixed . With this feature, I am able to take longer exposures and prevent the stars in the picture from trailing. The quality of the guiding adjustment is essential for a good picture and I always make and effort in making the best possible guiding setup. This is done by running an calibration test of the actual rig-setup( parameters/mount/backlash /guidingscope etc.)
When the autoguiding is acceptable I am ready to find my object and run my astrophotography session.
In Stellarium I search for my object(eg M31)In N.I.N.A. I sync this object with all its attributes( position etc.) to N.I.N.A. N.I.N.A. has its own object database so Stellarium is not essential but I like the visual presentation in this app. In Nina I ad my target and define how many pictures, exposure time, ISO etc. and setup guiding, center object etc. and hit run, this starts the capture session and while I observe I can sit back and drink some coffee. The pictures are automatically stored on my computer.
For planetary sessions it is almost the same procedure with only a few exceptions, I use the software “Firecapture” which is designed for capturing objects like the planets in our solarsystem while N.I.N.A is intended for Capturing DSO and long exposures. Together with Firecapture I use a dedicated Planetary camera like my ZWO ASI 485MC. This camera is extremely sensitive and acts more like a videocamera compared to a normal DSLR camera.
Ending the session
When the battery power is low its time to end the session but we need to take some calibration photo frames. I use the built-in module “frames” in N.I.N.A. and take min 20 Flats and Dark Flats. See this short explanation on why and how to take calibration frames( Bias, Dark, Flats and Dark Flats).
Now its time to park the telescope and power off all the equipment and wrap it up.
Unpacking equipment and drying
When unpacking all my equipment I make sure that all equipment will be properly dried and free of any moist/water/ice. I also make sure that Batteries are fully charged before my next Night session.
When the PC has reached ambient temperature and external powersupply is pluged in, I transfer all the data to a USB Hardisk.
In this step, the result of my effort will be revealed. I use different software to post process the pictures depending on the objects(planets or Deep sky objects) This is my software collection which consists of paid software and freeware applications:
DSS- Deep Sky Stacker
DSS- DeepSkyStacker 4.2.6 or 5.1.0
PIPP(Planetary Imiging PreProcessor
Topaz Labs ( DeNoise AI, Gigapixel AI, sharpen AI)
Creative Cloud Adobe PhotoShop
The final picture is now ready and done. Maybe You are satisfied, maybe not, The process of astrophotography involves so many steps where one only can learn and improve, this will lead to better finale results. I have learned much about weather condition and the great impact it has on photographing the objects in the night sky, The equipment and the adjustment to obtain the right setup, The photo session where it makes a difference whether You use the optimal ISO and exposure on the camera, the post processing of the pictures and getting all the data extracted and exposed. I don’t think that I will ever get tired of this hobby of imaging "things of the past".
Andromeda M31 :-)
I explain and illustrate my astrophotography setup in more detail on the next pages