Here comes the most essential part so you can produce a well balanced capture between milky way and the foreground object you assign. It is not actually a mandatory thing since you can still get a great shot by using a single exposure, especially when the light is sufficient to give you a proper details both for the background and foreground within one shot. However, if the light does not favour your side, still you can pursue your dreamy capture by taking several shots and combine it later on during post-processing. Sometimes, the result will be much more astonishing!
Taken on a relatively bright area, I managed to get this shot within a single exposure. The downside will be on the amount of the stars which are not that rich.
On Bromo case, whatever adjustment that I did in my camera, still I couldn’t get a good foreground details which can fulfil my expectation if I take the shot during that exact time. It was just too dark at that time and assigning a higher ISO will just ruin the image. That’s when I come to a decision for taking several exposures for my final image. If it is too dark at the moment and my camera is not capable to get the foreground details properly, so I need to wait until the morning light begins to shine.
For this Bromo shot, I was standing by from around 1AM when I noticed that I need more light to give the amount of details that I wish for the foreground. Then the waiting period began. I simply need to stand by there, keep my tripod and camera fixed on the exact position, and waiting until around 4.30 or 5AM when the twilight starts to appear. Sunrise lights is required to capture those details that I need. Around 5AM, my patience begins to pay off when I pleasantly examine all the foreground details which have been captured.
Without the patience, I wouldn't get this kind of foreground details. Patience does pay off!
Without persistence, waiting for 4-5 hours in a remote location - alone & awake - would be a tough job to do. That’s why it will be great if you have some friends that can accompany you during that waiting period or at least - you got mp3 player - as alternative to brighten up your night.
But instead of just sitting doing nothing, I suggest you to ocassionally take several shots between various periods. You know that the earth is rotating, means that the milky way position will be different from time to time. By observing this and take several shots along that night, you will have plenty of alternatives for which milky way position that will suit your foreground well. Keep in mind that several nature occurrences - in my case is when the volcano spurted its lava or during the sudden change of smoke direction - can also be properly documented. There is open-ending opportunity available during those 5 hours so just keep shooting and watch out your battery.