Well I’m starting to get everything dialed in, learning a new workflow from setup to capture to post processing is always a challenge, but oh so rewarding!
Tthe weather predictions (I use cloudfreenight.com) said the clouds would stay away last night and they were spot on. Heading outside at around 6.30pm I was greeted with no wind, a nice cool temperature and crystal clear skies. The only downside, was the almost full moon, but that’s okay, this is all a learning process and I was quite curious to see what results I could get in such conditions.
Time to setup, let me run you through the details of what I was using. I setup my standard manfrotto tripod which has the Star Adventurer base permanently attached to it now. This base gives very fine up down, left right movements only, and allows for the Star Adventurer star tracker to slot into it. I roughly point the base towards south, using the compass on my phone. I also adjust it so it is dead level according to the bubble level on the base.
Once that is done I attached the Star Adventurer, then attach the mount bracket which holds my camera on 1 end, and has a balancing counterweight on the other. I then attached my camera to the mount bracket, and the final piece of equipment, a guidescope with a ZWO 120mm-c camera on it which hangs off the L-Bracket of my camera, more on that later.
Then I run a power cable to my spot in the backyard, setup my chair, table, and laptop. I then have just 3 cables to connect. First cable I run from my camera to the USB on my computer. This allows me to control the camera exposure, shutter, etc all from the laptop and using that night big screen to check focus. The second cable runs from my guide scope camera to the other USB port on my laptop. The final cable runs from the guide scope camera to the Star Adventurer tracking mount.
Time to boot up the PC and get into the final stages of setup. This is probably the hardest part, but gets a lot easier with practice. You must align the tracking mount to be pointing at exactly the south celestial pole. This way the mount can rotate exactly matching the stars, which in turn allows much longer exposures, magic stuff!
This is where the little ZWO camera on the polar scope comes in very handy. Using a software program called Sharpcap Pro, which will take photos of the sky, working out where it is actually looking, and then tell you what changes you need to make on your mount (left/right or up/down but usually both). You slowly make adjustments aiming to get the numbers shown as close to zero as possible. Once done you lock everything down and now you are absolutely perfectly aligned. This night it took me all of 2 minutes to do after my rough alignment with the compass.
Now for the next fun part (did I mention I find all of these challenges extremely enjoyable? :)), finding the target in the sky you wish to shoot. I picked a real easy one tonight, the Orion Nebula. Having an app like Stellarium on your phone (and on the PC in this case) allows you to pull up a map of the stars exactly as they are now. I think start moving and rotating my camera on the mount to get it close to the location. Next, I fire up the Olympus Capture software, a free program for Oly users. Sony, Canon etc all have similar programs you can use. This is great as now I have a large screen helping me get focus dead on, can adjust all my settings without touching the camera, and can download the photos as they go to my PC and load them into Photoshop on the fly to check everything is working well.
The final piece of the software puzzle a program called PHD2 (or Push Here Dummy). This is for autoguiding. Sounds complicated but it’s very easy. The main premise here is PHD2 will lock onto a star it sees using the ZWO, constantly measure it’s movement, and tell the mount to speed up or slow down to keep the star dead center of the guiding. This simple process is the difference between taking a 2 second photo with no star tracker, a 30 second photo with a star tracker at 200mm, and a 5 minute exposure using a star tracker and guiding. The longer the exposure, the more light, the more detail, the more colour, the less noise…and tracking & guiding is the ultimate option.
With everything guiding and tracking I managed to get 1.5 hours of photos, each exposure at 3 seconds (moon was almost full so couldn’t go much longer), ISO 400, F5.6. I also added 10 dark frames for noise reduction and some flat and bias frames which are again used by the stacking software to correct noise and vignetting.
Running everything through DeepSkyStacker (free) and then post processing in photoshop (a steep learning curve for me for this style of photo) I ended up with my best shot of the Orion Nebular so far. A modified astro camera with the infra red filter removed would show a lot more nebulosity for sure, something to add to the future wish list.
I’ve made this photo available as a free download for you for your computer background, phone etc just click here and download from dropbox.
The lens is the one thing holding me back from better results at the moment. Next step is to try and get everything ticking over using a small telescope. Stay tuned for more fun astro adventures from my back yard. Stay safe everyone!