Starry night is one of the most beautiful scene in the world. As the technology develops, shooting pictures of star trails become easier. And we can record the beautiful starry night easily with a DSLR
We are going to talk about Star trail photography. There are mainly two methods to shoot photos of Star Trails
1. Stacking with softwares
2. Very long Exposure, such as 1 hour (not recommanded for Digital Camera users)
First, put your camera on a steady tripod.
Next, turn your camera to manual mode(M) and continous shooting mode, then set the correct shutter speed, aperture and ISO speed. For shutter speed, I recommand you to use shutter speed not slower 30 seconds, do not use bulb, so all the pictures will have the same brightness, and you don't have to release the shutter button for each shot. If the picture is still under exposed even the shutter is 30seconds, then increase the ISO or open up the aperture. My settings for star trails is usually like this: 30 seconds, F5.6, ISO 200. You can adjust the settings according to your situation
Then, shoot a lot of pictures in the same spot without moving your camera. 60-70 pictures (30 seconds exposure each) can provide a good result. The more pcitures you shoot, the longer the star trails will be. Also, turn off long exposure noise reduction function in your camera. The reason for this is because how it works it that if you take a 30 seconds picture, then it will take another 30 second to take a dark frame to reduce the noise. The 30 seconds delay will make the trails break into many pieces
Also, remember to shoot a few dark frames before you start, or after you finished shooting. The usage of dark frames will be mentioned later. To shoot a dark frame, cover up your lens with a lens cover and shoot with the setting you use previously. You will get a black picture.
The software we are going to use is called StarTrails. (Download it here: http://www.startrails.de/html/software.html) It is free and easy to use
Interface of StarTrails
Press the 'open; button(where the red circle is) to open the pictures you take, hold ctrl to select more than 1 picture
Then press the button 'open dark frames'(where the red circle is)
Dark Frames are used to reduce noise. When the lens is covered, no light can get to the light sensor, and the camera only records noise. With the darkframes, this software can identify the noise and get raid of them. This can increase the image quality.
Then, press the button with star trails on it (where the red circle is). Then wait till it completes it's work
At last, save the product by pressing the save button(where the red circle is)
First, is the moon phase. The best time for shooting star trails is during the time of new moon, because is a major source of light pollution, if the moon is too bright, the light of the moon will cover the light of the stars. You can also choose days with early moonset, if the moonset time is earlier than 11:00pm, then it is still ok even the moon is full. Also, do not choose cloudy days for star trails photography.
Direction is a factor that decides the shape of Star trails. If you are face the north, it will be a full circle. If you are facing south, it will be a semi circle. If you are facing east, it will be straight lines
The very first thing is: move away from city area!City area is a major source of light pollution, you will not see any stars near the city. Places like South Lantau Island, Clear water bay, Sai Kung, Po Toi Island will be a great place for star trail photography.
Being hungry for whole night is not enjoyable, bring some food. You can bring some energy bars, chocolate...etc. High Calories food will keep you warm if you are in cold places.