|Arches National Park, Utah|
First things first: what do we need? Actually the minimum requirements are fairly small:
1. Digital Camera: Duh! Obvious, but actually any digital camera with a manual mode will suffice (meaning that at least you should be able to control the exposure time). Of course one of those expensive DSLRs with gazillion automatic functions will make your life much easier, but any camera in which you can control exposure time will do.
2. A Sturdy Tripod: I don't know how to emphasize more the "sturdy" part, but it is fundamental. No matter how much you try to stay still and not touch anything, even if you are using a remote switch to take the photos, it is inevitable that some vibrations will occur and you need a strong tripod to minimize that shake. Just a mildly strong wind can make your tripod vibrate if it is not sturdy enough... and these photos require at least 15 to 30 minutes of exposure. Any shake will reduce your image sharpness... and we don't want that. So please, specially if you already invested a lot of money in your top-notch camera and sharp lens, don't be cheap and buy a $40 dollar tripod.
3. Patience... and most likely strong will and a hot beverage, because you will have to wake up between 2 and 4 in the morning, and most likely you will be sitting in the cold for a long time. For the photo above I woke up at 3:30 am, spent a good 30 minutes composing and then another hour shooting. So be patient.
There are a couple of optionals that I highly recommend:
4. Flashlight: you will be shooting in the middle of the night, and if you really want stars in your photos you probably are also in a place where there is almost no light... hence the flashlight. You can also use it to "paint" your foreground if there is no external light available and you don't want just a silhouette in your photo.
5. Remote switch: Not all cameras allow these, but if yours does, it is highly recommended. The basic switches will allow you to take the photo without pressing the camera's shutter button, and thus less camera shake. The more advanced ones will actually allow you to program the exposure time, number of photos, etc. It can simplify your shooting a lot.
Now that you have all you need the next thing on the list is... research. Indeed, this should be on your list every time you decide to go out somewhere to shoot. Today you can easily research your travel destination in Google Earth, Panoramio, Flickr, and so many other sites. There you can find what people have already shot, and thanks to the magic of geotagging you can even know where those images were taken. That will always help you prepare your trip and take advantage of the best spots to get a good photo.
Even if you don't care about this there is another set of important things you need to check out before you leave to make sure you can take these photos: the ephemerides of the place you will be visiting. There are several sites online where you can get them, so make sure you take a list with at least sunset, sunrise, moonset, moonrise and moon luminosity. As a side comment, if you are having a full moon during most of your trip, you will most likely not get a lot of stars. That is because when we have a full moon the Earth is in between the sun and the moon, hence as soon the sun sets, the full moon will rise and vice versa, so the really dark (and useful) part of the night will be minimal. But that is not bad... you can still do wonders when the moon is out, so just be creative. Remember that the amount of stars you can see depends on how much light is out there, so knowing when the sun and the moon won't be polluting your star-filled sky is essential. You definitely don't want to be waiting for 2 or 3 hours in the cold at 2 AM in the morning because the moon is still shining... and by having the sunset times you also know when to go to that great overlook you found earlier to take sunset pictures.
All set? Ready then, off you go. Once you arrive to your destination, while hiking around, look for interesting places. You need to do this during the day, otherwise you will waste your valuable night time looking for what to shoot instead of actually shooting. Even take a couple of photos to see if you find something interesting, but always remember that there will be little or no light, so think of shapes more than colours. If you are in the northern hemisphere, make sure you look for interesting places by looking to the north, and vice versa if you are in the south. That is if you want to get those concentric circles you see in the picture above. In that case I made sure I was pointing my camera to the NNE to have the circles centred to the left of the photo (and you can see the Polar Star in the centre). If you don't, then you will end up with lines streaks instead like in the photo below. Also notice that in that photo the moon was up when I took it, so the amount of stars was reduced significantly.
|Balanced Rock, Arches National Park, Utah|
|Stars at Dawn, South of Chile|
|Remains of a Chapel after the 2010 earthquake, Tapihue, Chile|