Take a star trail image in FOUR EASY STEPS
In the northern hemisphere the stars appear to rotate anticlockwise around one bright star: mag. +2.1 Polaris (Alpha (_) Ursae Minoris), also known as the Pole Star because it’s almost exactly on the celestial pole. Over 24 hours the VWDUV FRPSOHWH D FLUFOH DURXQG 3RODULV VR D PLQXWH ZLGH HOG H[SRVXUH featuring the Pole Star will show Polaris as a dot and the stars farther from it with curving trails. Here’s how to take a photo showing this dramatic effect.
Step 1
Use a wide-angle (16-28mm) or standard lens (35-70mm) for the EHVW UHVXOWV IRU VWDU WUDLOV DQG [ your camera to a tripod. Adjust the tripod legs so that they provide a solid base, and attach the remote shutter release so you don’t vibrate the camera when taking the shot.
Step 3
Decide whether you want to shoot short star trails near Polaris, or longer trails by aiming at a constellation nearer to the celestial equator. Ursa Minor is a good choice for the former while Orion works well for the latter.
Step 2
Select an ISO of 400 and open the aperture as wide as it will go (the smallest f/number setting). Switch the camera to bulb mode so there’s no limit to the length of the exposure, then focus. Make sure \RXU DVK LV GLVDEOHG DQG VZLWFK RQ the long-exposure noise reduction.
Step 4
Use the remote shutter release to take several exposures ranging in length from 5 to 30 minutes, then review them. If the sky is too bright in longer exposures, reduce the ISO to 100 or 200 and narrow the aperture to a larger f/number.