The Astronomy has always been one of my passion since I was a child. Looking at the stars make me calm and allows me to think, a verb not so used recently... But returning to the photography, two days ago I went with a friend of mine on the Mount Corrasi in order to take some pictures. The goal was the milky way, but also looking for some beautiful area where coming back a day for something particular. Mount Corrasi is near Oliena, a typical Sardinian village of the hinterland. This mountain is called the Sardinian dolomites due to the white colour and the presence of very few trees. Arriving on the top is quite challenging: you can use two way, by foot or by car. By foot is quite long and it takes some hours of walk, but it allows you to see beautiful places before arriving on the top, but if you are on hurry you can follow the main road, a bad off-road, that arrive directly on the top but you have to walk under the sun. That day we had at least 38 Celsius degrees and walking under the sun was too dangerous for us, so we preferred to use my car, an off-road car, to go until the top using the main road. Fortunately, my car is little, so it was easy to drive in that narrow road, where in some place is quite dangerous because you are really close to some cliffs.
Once arrived at the top we went to the higher part of the mountain, in order to find some interesting rock or particular scenery, or a tree...
For this photo, I hid behind the tree with a coloured flash. I waited for some second after the shot and I used the flash for lightening the tree. I had to try sometimes before that, but I'm really happy for the result.
I also took some other classical view of the Milky way, like these:
where the subjects are the rocks and the sky.
For these shots, I used the Sigma 14mm f/1.8 with my Sony A7RII, and I think is a good match. The Sigma is really sharp from corner to corner and allows to use a lower ISO setting due to its minimum aperture.
Before night I took a pano of the mountain, even though I don't like it so much...
How you can see there's a problem of exposition, so the sky isn't uniform how it should be, but at least it shows you the place where I was.
Messier 13 , a globular cluster
The first time I saw that globular cluster was many years ago, when I had a small telescope, a classical 119/1000 (actual they were 119/900, but mine was a 119/500 with a Barlow lens inside), and I stayed really amazed.
Recently I saw again the same globular cluster with the Meade SN 8", and the sight was really different and much more beautiful, but nothing compared with a photo, where you can see many things like a galaxy and thousands of stars. I know my picture isn't very good, I've lost a lot of signal during the post-processing, so I'd have to work better in order to improve the final picture. Of course, if you have some pieces of advise to give me, I'll be all ears.
The picture has been taken with an APO refractor (a triplet lens with a field flattener) and the ASI294MC camera. The guide camera was the ASI290MC with a 60/240mm guide scope.
I don't have taken so many light frames, so next time I'll try to take them again, in order to improve the S/N.
M51, Whirpool galaxy
This galaxy has been the very first try to take a decent astrophoto, because I had to try twice. In the first try there was the full Moon, and knowing that is not a good idea taking astrophoto when there's so much light, combined with city-lights (light pollution), I wanted to try in any way.
In fact the first try has been a complete failure:
As you can see there's a dark area above the galaxy, due to a moonlight reflection on the coma-corrector of my telescope.
So I only needed to wait the right moment, I mean without the Moon. And so it was!
These ones are the work of two nights, where I take 40 lights frames, 20 dark frames and 60 flat frames, for a total of 2 hours of lights integration:
For comparison, I put both the black-white version and the colour version, got in two different elaboration sessions.
For both, I've used PixInsight, but for the colour version, I had to study how to achieve some result, like removing vignetting, colour gradient and clean the noise present everywhere.
For pilot my setup I've used the ASI Air, where I got an excellent result:
The graph-guide was really close to the central line, sign that the mount was working very well, apart from some moments when there was the wind.
Speaking about frames, for this picture I've taken 40 light frames, 20 dark frames and 60 flat frames, but no bias frames because using a CCD camera it doesn't need to take bias frame. I've tried to take them, but PixInsight couldn't extract any information, so it was unuseful.
Finally, it's been a good experience. I've learnt a lot of things, what to do and what to not do, but if I want to keep on taking pictures in town, I need a filter for the light pollution.
Recently I've worked to improve my astrophotography equipment. Basically, I've made a powerbox for the mount and for two dew-heaters, but for a flat-box as well. The process it's been quite short, and I got my powerbox using a plastic tool-box and three lithium-batteries. So, after many works, you only expect to use them and you wait for the right night, a night without moon or at least a small moon-phase, in order to not have too much light pollution (I know, I'm living in a town, so it's really hard not having light pollution!!!!). Anyway, when you think the night is right, you soon discover another problem.... wind!!! Arrgh! After many cloudy nights, having even only one clear night is gold, but with the wind is always a big deal for astrophotography. But, as always, there's a solution.
Obviously, someone would tell, but wich windshield??? A tent? A solid wall? And what if I like to move it? The solution isn't so simple, but I think it might be practicable using Polionda sheets merged together to form a barrier for the wind. Polionda is really light and easy-portable so it should be very easy to use it every time I need it. For now, I've just made a small project on paper, but soon I'll buy all I need to make it, so stay tuned, I'll get back really soon.
That solution wasn't good enough. Unfortunately, Polionda isn't stable as I hoped, so with a medium wind it shakes a lot, and it's quite impossible to use it and protect the telescope from the wind. Even though with long laces, for blocking it somewhere, it isn't so useful, so I have to give up with this idea, a stupid idea.
On the Net, I've seen some portable tent. They are not so expensive, but I think it takes a bit time for mounting, and every time I want using the telescope I'd have to mount the tent, the telescope and so on. A bit of work for some pictures, maybe too work, and I don't know if it worths.
For now, I'll give up and I'll use my telescope in no-windy days, hoping to have no Moon as well!!!