© paulsastrophotography 2018

Astrophotography The Basics

In this section I will go through what you will need to get set up in Astrophotography like camera’s, telescopes and mounts etc… Believe it or not but Astrophotography is fairly simple. All you need to photograph objects like the stars and the Moon is your mobile phone or camera, a small cheap telescope and a tripod. Most people start out with a simple small telescope like a 50 or 60mm aperture and this is perfectly adequate for imaging the moon and objects like stars. Special adapters can be purchased for next to nothing that will mount your “point & shoot” camera or mobile phone to your telescope by taking the picture through the eyepiece. As long as you use the countdown timer on either of these to minimise scope shake then you can get some amazing images of the stars and Moon. Telescope: If you don’t already have a telescope and you are looking for your “first scope” it is always best to buy the best scope that your budget will allow. But a cheap small telescope is a great way to start out in Astronomy and Astrophotography. I would advise to steer clear of high street shop brand telescopes like Jessops and John Lewis as these are very cheaply made and you will certainly notice this cheapness in the optics and build quality of the scope and mount. You need to be looking at brands like SkyWatcher, Celestron, Meade and Vixen etc... You can find lots of great scopes on sites like eBay, Gumtree or Preloved. There are also plenty of websites that sell new and used telescopes. There are three types of basic telescope. Refractor Telescope Reflector Telescope Catadioptric Telescope Each of the above have their merits like; optic type, length and weight. I personally like to use refractors but reflectors rely on bouncing the light off of mirror’s and they have great optical properties at a lower price where Catadioptric scopes have the benefit of having very long focal lengths in a very short tube so make them more portable than reflector telescopes. If your budget allows then you certainly want to be looking at purchasing either an ED (extra-low dispersion) refractor or and Apochromatic (APO) refractor as these telescopes show very low or are completely free of false colour which can make blue halo’s around bright stars. But you will need a higher budget to afford one of these. most of the big names manufacture a couple of small refractors that have ED lenses which are a bit more affordable but these start at around £350 new but can also run in to thousands of pounds. I have their StarWave ED70 and it is an amazing scope and all of the images posted by me after January 2018 have been or will be taken with this scope. Mount: Whether you are using your telescope for visual only or for Astrophotography a sturdy mount is a must which will make taking images easier as you shouldn’t have to worry about your mount moving which means you can then concentrate on reducing the shake on your camera by using the aforementioned countdown function on your camera. The main types of mount are: German Equatorial Mount (GEM) Altazimuth Mount (Alt-Az) German Equatorial Mount (GEM) This type of mount is the best if you wish to take longer exposures. This mount needs to go through a process called Polar Alignment. If you watch a star over the period of an evening you will notice that it travels in a big arc across the sky, this is because the earth spins on an axis. If you locate Polaris which is the “North Star” you will notice that all the other stars appear to circle around it. In reality every star in the sky doesn’t have an orbit around Polaris it just looks like they do to anyone viewing from the northern hemisphere down here on Earth. Altazimuth (Alt-Az) Mount An Alt-Az moves on two axis, up down & left right. This is a great simple way to quickly move between targets but not so great for imaging due to the fact that you cannot polar align an Alt-Az. Two problems are determined from not being able to polar align: Firstly there is the motion of the mount, as the motors drive the mount in an up/down, left/right motion this means that the motion is not smooth as you can see in the diagram below. On top is the motion of an Alt-Az and underneath is a polar aligned GEM (Equatorial) If you look at the Alt-Az movement you will notice that the Nebula rotates as the mount follows the star across the sky this is because the mount keeps the camera level and is unable to rotate the camera as the Nebula rotates across the sky, this is called “field rotation” but using the GEM you can see that the Nebulae angle stays the same angle and the GEM does this by counteracting the rotation of the Earth and the camera is rotated along the right ascension axis as the Nebula is tracked across the sky. You are probably wondering what this has to do with imaging stuff in the sky. Basically an Alt-Az will not rotate with the sky, it just goes left/right & up/down. As the object rotates the Alt-Az will not rotate your camera at the same time, whereas a GEM will smoothly track the object and rotate your camera at the same time so that the object stays centred and at the correct rotation. Both mounts are capable of Astrophotography but to get longer exposures then you will need a GEM mount. Camera: For deep sky objects you will need some more specialised equipment, but still without the need to break the bank. For the majority of deep sky objects you will need a telescope or a long focal length lens attached to your camera. You will definitely need a DSLR camera or at the very least what is called a “System” camera. A System camera is as close to a DSLR as you can get without it being a DSLR. The difference between the two is basically what settings you are allowed to change in the menus. A System camera has limited functions when it comes to exposure & ISO etc… whereas a DSLR will give you full control over all the settings that the camera is capable of. I also own a System camera and have also self-modded it. I have had some good images from this camera but it is limited in the fact that it doesn’t give the “bulb” option which is a vital setting for taking longer exposures than 30 seconds which is usually the case when it comes to deep sky imaging. A system camera is definitely a cheaper “first” camera to practice with and you can get acceptable images of the brighter objects like the Orion Nebula, Dumbbell, star clusters and for imaging the moon. A DSLR camera gives you full control over the settings within the camera which allows for any length exposure. It also allows you to turn certain settings off that are not needed for Astrophotography and that can affect the outcome of your subs. If your budget allows and you feel confident enough then by all means get yourself a DSLR. The path I took was, Mobile phone, then point & shoot, then system camera and finally DSLR. You may think that this was expensive but with some savy snooping around I have not spent more than £80.00 on cameras in the space of a year. I already had a mobile phone and a point & shoot camera so I obviously didn’t have the expense of buying those. the only expense I had was for the system camera and the DSLR and they cost no more than £40.00 each. Admittedly I believe that I got very lucky on a certain auction site when it came to purchasing the DSLR. DSLR’s are by no means cheap and as I have just mentioned, I got lucky when buying mine but you should be able to get a DSLR body for around £150 and if you are lucky like I was then you may get one for cheaper. If your budget allows I would definitely recommend buying one new. Now, to the controversial bit, which camera to buy!! I use a second-hand Canon EOS 1000D which I have self modified for Astrophotography. You don’t need a modified camera for Astrophotography, but it does help as objects like Nebulae and large gas clouds can only be seen in certain wavelengths like H-Alpha etc… As mentioned a few times, I have self-modded my Canon and by following the very detailed instructions in this site www.dslrmodifications.com I confidently removed the filters and successfully Astro-modified my camera. A word of warning: Modifying your camera WILL VOID YOUR WARRANTY if you have one and there is the chance that you can damage your camera beyond repair. If you feel at all uneasy about modifying your own camera then do not attempt it yourself. There are people that you can send your camera to who will do the mod for you but this can cost between £75 and £150, but that is still cheaper than having to buy a new camera because you have ruined your current one. I am not trying to put anyone off from self modifying as I found it a fairly simple process that took me one and a half hours to complete and if you follow the instructions on the site mentioned above then you should have no problems whatsoever. There are a few Astrophotographers in both of the Astronomy groups that I belong to and each of them has their own preference on what make of camera that they prefer. One gentleman naming no names, Chris, once told me off for confusing his Nikon for a Canon. A mistake I learned fairly quickly to avoid in the future. The two main makes out there are Canon & Nikon (in no particular order). I have used both but the Nikon I used didn’t have Live-view so when it came to focusing it was a very long winded process by means of taking an exposure, looking at it, then working out which way to focus the telescope, then taking another image and checking the focus again…so on & so forth. sometimes it took me a good 15 minutes to get the focus right. When it comes to deep sky objects you will not be able to use live-view to focus as they are too dim, but I learned a neat trick by which you focus on the Moon then all you need to do is fine tune your focus on the object you wish to image. There are plenty of sites on the internet that give different ways to focus so it is worth looking around to see which method suits you best. So in my eyes either Canon or Nikon (Still in no particular order) are good for Astrophotography but finding one with live-view I think is a good idea. There are also plenty of websites out there that detail good cameras for Astrophotography. My latest camera is a ZWO ASi 120mm planetary/guiding camera which I will be using mainly for guiding which will allow me to extend my exposure time quite considerably, but I will also be using it on the planets and with Jupiter making an appearance in the next month or so I will be making use of the planetary side of the camera. I will of course include the details of this camera along with the images that I post.
© paulsastrophotography 2018

Astrophotography The Basics

In this section I will go through what you will need to get set up in Astrophotography like camera’s, telescopes and mounts etc… Believe it or not but Astrophotography is fairly simple. All you need to photograph objects like the stars and the Moon is your mobile phone or camera, a small cheap telescope and a tripod. Most people start out with a simple small telescope like a 50 or 60mm aperture and this is perfectly adequate for imaging the moon and objects like stars. Special adapters can be purchased for next to nothing that will mount your “point & shoot” camera or mobile phone to your telescope by taking the picture through the eyepiece. As long as you use the countdown timer on either of these to minimise scope shake then you can get some amazing images of the stars and Moon. Telescope: If you don’t already have a telescope and you are looking for your “first scope” it is always best to buy the best scope that your budget will allow. But a cheap small telescope is a great way to start out in Astronomy and Astrophotography. I would advise to steer clear of high street shop brand telescopes like Jessops and John Lewis as these are very cheaply made and you will certainly notice this cheapness in the optics and build quality of the scope and mount. You need to be looking at brands like SkyWatcher, Celestron, Meade and Vixen etc... You can find lots of great scopes on sites like eBay, Gumtree or Preloved. There are also plenty of websites that sell new and used telescopes. There are three types of basic telescope. Refractor Telescope Reflector Telescope Catadioptric Telescope Each of the above have their merits like; optic type, length and weight. I personally like to use refractors but reflectors rely on bouncing the light off of mirror’s and they have great optical properties at a lower price where Catadioptric scopes have the benefit of having very long focal lengths in a very short tube so make them more portable than reflector telescopes. If your budget allows then you certainly want to be looking at purchasing either an ED (extra-low dispersion) refractor or and Apochromatic (APO) refractor as these telescopes show very low or are completely free of false colour which can make blue halo’s around bright stars. But you will need a higher budget to afford one of these. most of the big names manufacture a couple of small refractors that have ED lenses which are a bit more affordable but these start at around £350 new but can also run in to thousands of pounds. I have their StarWave ED70 and it is an amazing scope and all of the images posted by me after January 2018 have been or will be taken with this scope. Mount: Whether you are using your telescope for visual only or for Astrophotography a sturdy mount is a must which will make taking images easier as you shouldn’t have to worry about your mount moving which means you can then concentrate on reducing the shake on your camera by using the aforementioned countdown function on your camera. The main types of mount are: German Equatorial Mount (GEM) Altazimuth Mount (Alt-Az) German Equatorial Mount (GEM) This type of mount is the best if you wish to take longer exposures. This mount needs to go through a process called Polar Alignment. If you watch a star over the period of an evening you will notice that it travels in a big arc across the sky, this is because the earth spins on an axis. If you locate Polaris which is the “North Star” you will notice that all the other stars appear to circle around it. In reality every star in the sky doesn’t have an orbit around Polaris it just looks like they do to anyone viewing from the northern hemisphere down here on Earth. Altazimuth (Alt-Az) Mount An Alt-Az moves on two axis, up down & left right. This is a great simple way to quickly move between targets but not so great for imaging due to the fact that you cannot polar align an Alt-Az. Two problems are determined from not being able to polar align: Firstly there is the motion of the mount, as the motors drive the mount in an up/down, left/right motion this means that the motion is not smooth as you can see in the diagram below. On top is the motion of an Alt-Az and underneath is a polar aligned GEM (Equatorial) If you look at the Alt-Az movement you will notice that the Nebula rotates as the mount follows the star across the sky this is because the mount keeps the camera level and is unable to rotate the camera as the Nebula rotates across the sky, this is called “field rotation” but using the GEM you can see that the Nebulae angle stays the same angle and the GEM does this by counteracting the rotation of the Earth and the camera is rotated along the right ascension axis as the Nebula is tracked across the sky. You are probably wondering what this has to do with imaging stuff in the sky. Basically an Alt-Az will not rotate with the sky, it just goes left/right & up/down. As the object rotates the Alt-Az will not rotate your camera at the same time, whereas a GEM will smoothly track the object and rotate your camera at the same time so that the object stays centred and at the correct rotation. Both mounts are capable of Astrophotography but to get longer exposures then you will need a GEM mount. Camera: For deep sky objects you will need some more specialised equipment, but still without the need to break the bank. For the majority of deep sky objects you will need a telescope or a long focal length lens attached to your camera. You will definitely need a DSLR camera or at the very least what is called a “System” camera. A System camera is as close to a DSLR as you can get without it being a DSLR. The difference between the two is basically what settings you are allowed to change in the menus. A System camera has limited functions when it comes to exposure & ISO etc… whereas a DSLR will give you full control over all the settings that the camera is capable of. I also own a System camera and have also self-modded it. I have had some good images from this camera but it is limited in the fact that it doesn’t give the “bulb” option which is a vital setting for taking longer exposures than 30 seconds which is usually the case when it comes to deep sky imaging. A system camera is definitely a cheaper “first” camera to practice with and you can get acceptable images of the brighter objects like the Orion Nebula, Dumbbell, star clusters and for imaging the moon. A DSLR camera gives you full control over the settings within the camera which allows for any length exposure. It also allows you to turn certain settings off that are not needed for Astrophotography and that can affect the outcome of your subs. If your budget allows and you feel confident enough then by all means get yourself a DSLR. The path I took was, Mobile phone, then point & shoot, then system camera and finally DSLR. You may think that this was expensive but with some savy snooping around I have not spent more than £80.00 on cameras in the space of a year. I already had a mobile phone and a point & shoot camera so I obviously didn’t have the expense of buying those. the only expense I had was for the system camera and the DSLR and they cost no more than £40.00 each. Admittedly I believe that I got very lucky on a certain auction site when it came to purchasing the DSLR. DSLR’s are by no means cheap and as I have just mentioned, I got lucky when buying mine but you should be able to get a DSLR body for around £150 and if you are lucky like I was then you may get one for cheaper. If your budget allows I would definitely recommend buying one new. Now, to the controversial bit, which camera to buy!! I use a second-hand Canon EOS 1000D which I have self modified for Astrophotography. You don’t need a modified camera for Astrophotography, but it does help as objects like Nebulae and large gas clouds can only be seen in certain wavelengths like H-Alpha etc… As mentioned a few times, I have self-modded my Canon and by following the very detailed instructions in this site www.dslrmodifications.com I confidently removed the filters and successfully Astro-modified my camera. A word of warning: Modifying your camera WILL VOID YOUR WARRANTY if you have one and there is the chance that you can damage your camera beyond repair. If you feel at all uneasy about modifying your own camera then do not attempt it yourself. There are people that you can send your camera to who will do the mod for you but this can cost between £75 and £150, but that is still cheaper than having to buy a new camera because you have ruined your current one. I am not trying to put anyone off from self modifying as I found it a fairly simple process that took me one and a half hours to complete and if you follow the instructions on the site mentioned above then you should have no problems whatsoever. There are a few Astrophotographers in both of the Astronomy groups that I belong to and each of them has their own preference on what make of camera that they prefer. One gentleman naming no names, Chris, once told me off for confusing his Nikon for a Canon. A mistake I learned fairly quickly to avoid in the future. The two main makes out there are Canon & Nikon (in no particular order). I have used both but the Nikon I used didn’t have Live-view so when it came to focusing it was a very long winded process by means of taking an exposure, looking at it, then working out which way to focus the telescope, then taking another image and checking the focus again…so on & so forth. sometimes it took me a good 15 minutes to get the focus right. When it comes to deep sky objects you will not be able to use live-view to focus as they are too dim, but I learned a neat trick by which you focus on the Moon then all you need to do is fine tune your focus on the object you wish to image. There are plenty of sites on the internet that give different ways to focus so it is worth looking around to see which method suits you best. So in my eyes either Canon or Nikon (Still in no particular order) are good for Astrophotography but finding one with live-view I think is a good idea. There are also plenty of websites out there that detail good cameras for Astrophotography. My latest camera is a ZWO ASi 120mm planetary/guiding camera which I will be using mainly for guiding which will allow me to extend my exposure time quite considerably, but I will also be using it on the planets and with Jupiter making an appearance in the next month or so I will be making use of the planetary side of the camera. I will of course include the details of this camera along with the images that I post.