“When he shall die,
Take him and cut him out in little stars,
And he will make the face of heaven so fine
That all the world will be in love with night
And pay no worship to the garish sun.”
– William Shakespeare, Romeo and Juliet
O Milky Way, What art thou you bright band thingy in the sky?
What is it about the night sky that fascinates us so much? There’s nothing quite like lying down on a bed of soft grass gazing up at the heavens as a canopy of stars shine bright and tell you tales of yore. Astrophotography is a very very interesting experience and if you’ve not tried your hand at it before, I highly recommend that you should. I say this because after one time of shooting stars, you will be dying for another chance to get out there and capture the glory of our galaxy. Right then, what about the Milky way? According to Wikipedia, The Milky Way is the galaxy that contains our Solar system. This name derives from its appearance as a dim “milky” glowing band arching across the night sky, in which the naked eye cannot distinguish individual stars.The Milky Way appears like a band because it is a disk-shaped structure being viewed from inside. All right, enough trivia.
Challenges and difficulties thy shall encounter : I have told thee often, and I re-tell thee again and again
While it would be supremely awesome to walk out each night and see the Milky way with your naked eyes, such a scenario rarely materializes, unless you are like one of those guys in a Geico Ad living under a rock in the desert. Even so, it would be difficult because the moon plays a huge role in you being able to see the Milky way. The main impediment to seeing and capturing the Milky way is the lack of dark skies. The cities we live in usually light up in the night and this produces what is called Light Pollution. Basically, these large neon lights and their close cousins make the sky all bright and the visibility of the stars reduces. Hence people have to travel away from these bright cities to even stargaze! Sometimes, just moving away from city lights isn’t quite enough. Their influence spreads much farther than their borders. To summarize this long winded point, I say, find a super dark place like a desert, a mountain range or a forest. Some coastal areas work too, but these are quite rare to find.
Next pick a day when the moon isn’t there in the sky, or shy away from the moonlight as much as possible while choosing your spot. Usually new moon days in the summer are ideal for shooting the Milky way. All right then, great! You’ve successfully found a dark spot! Congrats! You are now only a couple of steps away from recording our glorious galaxy on your sensor. So what are those steps then?
For starters, finding a good composition. The milky way has now been shot to death, almost everyone has a shot of it and most of these shots look the same! The real trick is coming up with something new. I’ll delve into that soon. Another potential stumbling block is the camera you have. You’ll need a camera that has a decent ISO performance. To shoot the Milky way, you will need ISO values between 1000 and 3200. A camera that has a decent noise performance at this ISO range helps a lot. That doesn’t mean that you can’t shoot it if your camera isn’t that good, but, you will be limited by the ISO performance in terms of what you can shoot. On that note, lets jump into some tech talk. I’ll next discuss what you need in terms of equipment and also share some tips on planning your shoot.
Equipment and planning : Away, and mock the time with fairest show
Before you go on your noble quest O brave knight/fair maiden, thou shall need the following to slay any dragons along the way :
- A camera with good noise performance in the ISO range of 1600-3200.
- A fast, wide angle lens which has a large aperture, e.g. f/2.8
- A remote timer release ( Preferably, but not essential)
- Extra batteries for your camera ( A battery grip would work wonders)
- A sturdy tripod
- A flashlight and/or headlamp
- A compass
- Coffee/Tea and other snacks to consume whilst waiting for the shot
While you can use any lens you desire to capture stars, there are some salient aspects that you should be aware of when you choose a lens for the shoot. First, the stars are not going to stay still and pose for you all night (They have jobs you know?). Since the earth rotates, stars appear to be moving across the night sky. What does this mean for you? Basically, this means that there is an upper limit to the shutter speed that you can use to get pinpoint stars before they start streaking. While increasing the ISO and lowering the aperture helps, it does not solve the problem always. An increase in ISO means more noise, and changing the ISO-Aperture combination does not always guarantee a streak free shot. What does all this have to do with lenses? Fast, Wide Angle lenses can really help you in stretching the limits on you shutter speed. More on the shutter speed aspect later. Extra batteries always help since you never know when you’ll run out of juice for your camera. In the dead of night, it’s not easy getting new batteries right? Also, it can get very cold out there, so layer up, and be prepared for chilly weather (Hot beverages help and they can keep you awake!). Another thing that is very important is to know the lay of the land well. If you are visiting a place for the first time, get there ahead of time and scope out the area. Never take risks in the dark, it’s not fun!
Compelling composition in the dark : What`s that, I pray?
All righty then, let’s get to the fun part, shooting the Milky Way. Most of the heavy lifting is needed during setup. Taking the actual shot is very very easy. Let’s break this section into byte sized chunks shall we? Before we begin, I’m assuming your aperture is set to the widest your lens can go, e.g. f/2.8 . Trust me you’ll need it!
- Manual Focusing : Perhaps one of the more challenging steps in the process. In order to render your stars sharp and as pin-pointy as possible, you need first pre-focus to infinity. In order to do this, first switch your lens from Auto Focus to Manual Focus mode. The reason you do this is because your camera and lens system cannot auto focus in the dark. Additionally, if you are including foreground in your shot (which I highly recommend), then you need to ensure an optimum depth of field. For more on this and depth of field calculation, check out http://dofmaster.com/dofjs.html. Most lenses nowadays have focusing rings with distance markers. This makes your life a lot easier while choosing the exact distance to focus on. Another neat way of focusing manually is to use the Live View option on your camera if you have it. While in live view, zoom into any bright object in the sky (mostly a star or in some cases the moon) and adjust the focusing ring until the object appears tack sharp on the screen. While it takes a little bit of time to get the hang of this, rest assured it becomes second nature soon. I’d recommend taking a test shot after this to see if everything appears sharp and in focus. That way, you can focus on altering your composition and other things without worrying about a botched shot.
- Choosing the correct shutter speed : As I mentioned before, stars tend to move after a certain exposure time, so choosing the right shutter speed is key. There is a rule/suggestion known as the rule of 600 which can help you choose the correct shutter speed based on the focal length you are shooting at. Here’s how it works:
- Take 600 and divide it by the focal length you are shooting with. The resulting number is the number of seconds you can expose your shot for before the stars start moving. For example if you are shooting at 20mm, then 600/20 = 30 seconds is the maximum exposure time you can get away with before the stars start moving.
- Do note, that this rule only works for a Full Frame Camera as described above. In order to get the number for a Crop Sensor like a Canon 7D for example, you need to divide 600 by the Effective Focal length of the lens. For example, if you are shooting at 20mm on a crop sensor with a crop factor of 1.6, then the maximum shutter speed is 600/(1.6*20) = 18.75 ~ 19 seconds. You may be thinking that 19 seconds is a long time, but in terms of astrophotography, it’s nothing at all! Why am I saying this? Read on to the next point.
Footnote: This whole procedure involves a lot of trial and error. Work around with the shutter speed until you get the right shot. The rule/suggestion of 600 is not written in stone. It helps you find a good starting point. However, it is up to you to play around and find the best shutter speed for you.
- ISO – I SO want to avoid noise : In the previous point, I mentioned that 19 seconds is peanuts when it comes to night time exposure. Why? The light available in the environment, known as Ambient light does very little to help you. So if you are left stuck with an underexposed shot at a maximum exposure time of 15 seconds, and you are already wide open as far as aperture goes ( f/2.8 or the maximum your lens can go), then you NEED to up the ISO. Don’t worry about noise and bump the ISO up. Most cameras deliver surprisingly good performance at high ISOs. So, go ahead and up the ISO as much as needed. Also note that you can record a lot of sky detail with higher ISOs.
- Composition – Run of the mill is boring : Everyone can shoot the Milky Way guys. It’s easy once you know how. However, what separates the great shots from the good is the composition. Having a compelling foreground in front of the Milky way makes a huge difference to the shot. Just imagine, having the Milky way reflect off the placid waters of a lake, or having it arch over a mountain range. Shots like these, where the photo stands on it’s own without the Milky way in it, really make the difference. So it’s good to come early around or after sunset and frame up a composition. Then it’s a patient waiting game for the right moment. Additionally, you could also light paint and get some really cool effects into your shot. The possibilities are endless!
Experience of taking the shot : This gentle and unforced accord sits smiling to my heart
My first experience at shooting the Milky Way was awesome, for lack of a better term. I had a lot of fun, and while it was challenging, it was nonetheless very rewarding. I realized you can read all you want about the proper technique, equipment and other factors, but there is NOTHING like actually being out there in pitch darkness, fumbling with a torch light, and focusing your camera manually on a distant star and waiting with bated breath as a miracle pops up on your LCD. It’s a very very surreal experience. So go out there and have fun guys!
Part II will deal with processing the Milky Way Image! Stay tuned…
Comments, Questions or Suggestions? Feel free to drop a note below!