- Astrophotography
- 07 Aug 2017 02:37:17 pm
- Last edited by Nik on 08 Aug 2017 07:36:08 am; edited 1 time in total
A new topic for all your astrophotography adventures! Please post any cool images, tips and whatever else you deem appropriate.
Let me start right away with a short account of my own first steps in the realm of astrophotography:
So, I received a used but very decent camera, a Sony Cyber-shot DSC HX400V. It is by no means a camera for astrophotography. Nor is it a telescope, for that matter. But it comes very close.
With a stunning zoom of 50x, or a focal length of 1200mm, I quickly discovered I could zoom in on the moon nicely. That was when I took my first astrophotograph. For a few months, I've been taking shots of the moon in this phase and that - I posted one of the best images here.
I did some research and eventually stumbled upon the blog BudgetAstro.net. There I learned about stacking. And finally, two days ago, I decided to try it out - I documented my attempt here. Now, I don't have much equipment - just a tripod, a few filters and the camera, not even a remote shutter control - so I was dealing with lots of motion blur, and the results were not quite satisfying. Cemetech admin Alex suggested I use the self timer to avoid motion blur when triggering the shutter. I did some research yesterday and found out that my camera can do better - I can use my smartphone as a remote control.
With this in mind, I had another attempt yesterday and last night. And this time I went further than just the moon.
During the day I took a few shots of the sun. Unfortunately, it was cloudy, so the sun was partially obstructed. Then, my filter (I used two and three relatively rotated polarization filters to create a strong darkening effect) seems to absorb longer wavelengths better - the image turned purple. There was still some lens flaring, and something was causing a blur.
The stuff on the bottom of the sun are clouds. I tried to pick a moment when there were none obstructing the sun, but it seems I missed it by a few seconds.
I enhanced the image slightly to get this:
Do you see that speck of dust on the sun? This is (drumroll) Region 2670, a sunspot!
Later, tonight, I attempted a few moon pictures and gave stacking another try. This time, I used software: AutoStakkert! does the job pretty nicely. Most places recommend Deep Sky Stacker, but their page explicitly says that it is not suitable for planets, while AutoStakkert! was developed exactly for this job. I have to say, the result turned out much better than last time, although you can see some artifacts on the moon's edge (zoom in at about 1 or 2 o'clock, for example):
Unprocessed frame right out of the camera for noise comparison:
And after I was done with the moon images, I went on a tour to find Andromeda, also called M31, as it is the 31st entry in the famous Messier catalog. I did not manage to properly photograph M31, you can barely resolve it bigger than a speck of dust. But I was not using the camera's full potential - much rather I had navigation troubles. I could not target the area properly, thus I had to keep zoomed out not to loose my location. Here, the Android app Star Map, the desktop program Stellarium and the web app astrometry.net proved incredibly useful - the Star Map app allows you to see star names and constellations in an augumented reality view, Stellarium is a very detailed star map for desktops, and astrometry.net allows you to upload pictures, recognizes the star pattern there, and spits out detailed location data and what is shown on the picture.
Anyway I ended up taking a few images of Cassiopeia and some extremely noisy pictures for my own orientation (I could like quarter the exposure time by ramping up ISO, so I did that to speed up "navigation"). The blur seen in the sun images persisted. I believe it is due to the way I focused - while I used the autofocus for the moon, I used manual focus for the stars and sun and I turned it all the way to the maximum distance, which probably goes a bit beyond infinity. I will try to focus a distant light or something next time instead.
In the end I compiled a small "guide" or "map" for finding the Andromeda Galaxy on the sky, as a replacement for no proper pictures. All you need to be able to do in advance is recognizing the constellation of Cassiopeia.
The green lines and labels name the constellations you're looking for, the yellow lines and labels are imaginary lines that help (at least me personally) to locate the final target, and the red ellipse shows where M31 indeed is.
When you found Cassiopeia, you take the sharper of the two "arrows" and see where it points. In that direction, you will find a perpendicular line of three bright stars, and on it, an "L" shape of medium-bright stars. Right in the middle below the L, you'll see a faint, diffuse glow - that is the Andromeda Galaxy.
I hope this post was not too long and contained enough information for anyone to replicate what I did, and maybe we will eventually get to take photos of some nebula or galaxy together!
Let me start right away with a short account of my own first steps in the realm of astrophotography:
So, I received a used but very decent camera, a Sony Cyber-shot DSC HX400V. It is by no means a camera for astrophotography. Nor is it a telescope, for that matter. But it comes very close.
With a stunning zoom of 50x, or a focal length of 1200mm, I quickly discovered I could zoom in on the moon nicely. That was when I took my first astrophotograph. For a few months, I've been taking shots of the moon in this phase and that - I posted one of the best images here.
I did some research and eventually stumbled upon the blog BudgetAstro.net. There I learned about stacking. And finally, two days ago, I decided to try it out - I documented my attempt here. Now, I don't have much equipment - just a tripod, a few filters and the camera, not even a remote shutter control - so I was dealing with lots of motion blur, and the results were not quite satisfying. Cemetech admin Alex suggested I use the self timer to avoid motion blur when triggering the shutter. I did some research yesterday and found out that my camera can do better - I can use my smartphone as a remote control.
With this in mind, I had another attempt yesterday and last night. And this time I went further than just the moon.
During the day I took a few shots of the sun. Unfortunately, it was cloudy, so the sun was partially obstructed. Then, my filter (I used two and three relatively rotated polarization filters to create a strong darkening effect) seems to absorb longer wavelengths better - the image turned purple. There was still some lens flaring, and something was causing a blur.
The stuff on the bottom of the sun are clouds. I tried to pick a moment when there were none obstructing the sun, but it seems I missed it by a few seconds.
I enhanced the image slightly to get this:
Do you see that speck of dust on the sun? This is (drumroll) Region 2670, a sunspot!
Later, tonight, I attempted a few moon pictures and gave stacking another try. This time, I used software: AutoStakkert! does the job pretty nicely. Most places recommend Deep Sky Stacker, but their page explicitly says that it is not suitable for planets, while AutoStakkert! was developed exactly for this job. I have to say, the result turned out much better than last time, although you can see some artifacts on the moon's edge (zoom in at about 1 or 2 o'clock, for example):
Unprocessed frame right out of the camera for noise comparison:
And after I was done with the moon images, I went on a tour to find Andromeda, also called M31, as it is the 31st entry in the famous Messier catalog. I did not manage to properly photograph M31, you can barely resolve it bigger than a speck of dust. But I was not using the camera's full potential - much rather I had navigation troubles. I could not target the area properly, thus I had to keep zoomed out not to loose my location. Here, the Android app Star Map, the desktop program Stellarium and the web app astrometry.net proved incredibly useful - the Star Map app allows you to see star names and constellations in an augumented reality view, Stellarium is a very detailed star map for desktops, and astrometry.net allows you to upload pictures, recognizes the star pattern there, and spits out detailed location data and what is shown on the picture.
Anyway I ended up taking a few images of Cassiopeia and some extremely noisy pictures for my own orientation (I could like quarter the exposure time by ramping up ISO, so I did that to speed up "navigation"). The blur seen in the sun images persisted. I believe it is due to the way I focused - while I used the autofocus for the moon, I used manual focus for the stars and sun and I turned it all the way to the maximum distance, which probably goes a bit beyond infinity. I will try to focus a distant light or something next time instead.
In the end I compiled a small "guide" or "map" for finding the Andromeda Galaxy on the sky, as a replacement for no proper pictures. All you need to be able to do in advance is recognizing the constellation of Cassiopeia.
The green lines and labels name the constellations you're looking for, the yellow lines and labels are imaginary lines that help (at least me personally) to locate the final target, and the red ellipse shows where M31 indeed is.
When you found Cassiopeia, you take the sharper of the two "arrows" and see where it points. In that direction, you will find a perpendicular line of three bright stars, and on it, an "L" shape of medium-bright stars. Right in the middle below the L, you'll see a faint, diffuse glow - that is the Andromeda Galaxy.
I hope this post was not too long and contained enough information for anyone to replicate what I did, and maybe we will eventually get to take photos of some nebula or galaxy together!