The most important thing is to know where to look actually look for the Milky Way.
You can use an app (for example Stellarium) to help you plan the right spot for your photoshoot. You should also find a location as dark as possible (you can get away with some light pollution but the darker it is, the better) and choose a day when the weather is clear and there is no full moon.
The Milky Way is only half the shot
For me, the most awe inspiring Milky Way images are those that show the galactic core in relation to earthly locations and objects. Something as mundane as a person on a camp chair can look really dramatic when framed by the phenomenon of The Milky Way.
Think hard about what you’d like to put in the foreground of your Milky Way shot. If you get perfect conditions and execute perfect technique you’ll still get a boring shot if you don’t put something else in your frame to ground the viewer. Pick an interesting foreground feature and maybe try a little light painting to make your Milky Way shots truly awesome.
Super wide angle lenses are ideal for shooting nightscapes because they don’t usually produce much bokeh. By that, I mean that even when set to maximum apertures of f/1.4 you’ll still be able to get a great deal of your image in focus – if you focus correctly. The last thing you want is a sharply focused Milky Way with a foreground that is completely blurred in soft, creamy bokeh, so leave the lovely Sigma 85mm f/1.4 at home.
It’s not the end of the world if you’ve got a standard, all-purpose, kit lens that isn’t very fast. You’ll still get some decent Milky Way shots because you’ll be using long exposures and high ISO settings to maximize your camera’s sensitivity to light.
With night photography you’ll be forced to use high ISO settings during your long exposures so it’s vital to have a camera that can operate at ISO 3200 and above, but more importantly still produce good image quality. No matter what camera you use, the image quality will take a major hit when you start to crank up the ISO numbers, that’s unavoidable.
Don’t feel that you absolutely MUST have the most expensive gear. Work with what you’ve got, then upgrade when you become addicted, and can’t resist the temptation to splurge. The one thing you’re going to really need your camera to have is a good Live View screen or an EVF (electronic viewfinder). You will use this to focus and compose your shots.
You need a tripod
It’s dark, you’re going to be doing long exposures, and that means you have to use a tripod. Read my article on the reasons why a good tripod is essential for any kind of outdoor photography. For night photography a tripod is obligatory.
Shoot in M (Milky Way Mode) and Shoot RAW
You want full control over every aspect of your shot so set your camera to Manual mode. This allows you to control the ISO, the shutter speed, the aperture and white balance. Always shoot in RAW.
Set your focus on a star
Set your aperture to the widest, fastest setting it can achieve (smallest number such as f/2.8). This wide aperture will expose your sensor to the maximum amount of light. Using your camera’s Live View or EVF, point it at the brightest star you can see until a small dot of light appears in the centre of your view. Zoom in (magnify the view NOT zoom the lens) so that you see that tiny little dot as large as possible. Now turn the focus wheel on your lens until the star becomes a sharp, tiny pin-point of light. Don’t rush this, take your time and get it right. Whatever you do, don’t blindly set your focus to infinity by cranking your focus wheel until it reads Infinity (?), you’ll just end up with blurred images.
When shooting The Milky Way I prefer to shoot with my White Balance set to Incandescent (aka Tungsten) which I believe is Sony’s version of Tungsten. I like the blue hue and it also displays a lot of contrast in my camera’s EVF so that I can clearly see The Milky Way. When I process my images later I often reset the White Balance back to Auto (AWB) mode for a more realistic neutral color temperature.
Set your ISO
For your actual Milky Way shot you want to use the lowest ISO setting you can get away with so dial it down to ISO 2000 and see if that gives you good results. You can always increase it to ISO 3200 after a few more test shots. I personally rarely go above ISO 3200 as my RAW files tend to degrade significantly at that point.
Shutter speed versus ISO
From this point on you’re going to be juggling your shutter speed and ISO setting to get the most light sensitivity, while still having a shutter speed fast enough to avoid getting star trails. Even a very small star trail just results in a Milky Way shot that lacks clarity. Try to limit your shutter speed to a maximum of 15 seconds so that you can keep the stars in your image sharp and trail free.
Try a 30 second exposure
I know I just said to keep your shutter speed to a maximum of 15 seconds but I always like to take an additional shot with a 30 second exposure to capture a much brighter Milky Way. I do this if I’m planning on publishing a web-only (low resolution) image because the slight star trail caused by the longer exposure won’t be very evident in a low-res web image. The stars will still look sharp enough but will have a much brighter appearance than a 15 second exposure.
Source: Digital Photography School