Star Trails Photography.

Star Trails photography can only be done on clear sky days for obvious reasons.  Mid summer or October when the monsoon is over is the season for star photography.  For star trails the camera is kept in a continuous shooting mode for at least one and a half hours.  Then you composite all the pictures in a special software like StarStax.

This is a composite of many photographs taken on continuous shooting at Naneghat, near Mumbai.  It helps if you are at a higher altitude to escape the smog and the light pollution from the city.  Since one camera is continuously occupied shooting it is better to take another camera to shoot the Milky Way or Light Painting.

Here a wide angle lens is de rigueur.  First step is to identify the Pole Star since it does not move.  In the above photo it is seen as a pin point of light round which all the stars "move".  The stars are actually stationary objects and it is the rotation of the earth which gives rise to the star trails.  Identifying the wheelbarrow constellation aka Big Dipper is the key to locate the Pole Star.

Set the lens to focus just before infinity and take a test shot to check if the stars can be seen in the image.  Set the shutter speed to 30 seconds and using a cable release put the camera on continuous shooting mode.  Lock the cable release so that the camera continues clicking for the next two hours.  A tripod and a cable release are essential for shooting star trails.

A fast SD memory card is also needed so that the camera does not waste time buffering to a slow memory card.   I use a Lexar Professional 600x Speed SD card of Class 10.  It helps wherever continuous shooting mode is required.