Photographing the night sky requires special photography equipment, a little knowledge of astronomy, perfectly clear skies, and lots and lots of time, both to capture the images and to process them. Nebulas and other deep space objects, while enormous, are also incredibly far away. As a result, the light we see here on Earth from any one image is incredibly dim. This is why most deep space objects cannot be viewed with the naked eye.

Telescopes and some camera lenses are used to focus on the object and frequently specialty cameras are utilized to capture the images. In order to capture enough light to make the object visible, the camera must capture HOURS of exposure time, sometimes over multiple nights. A single astrophotograph is made up of many individual images, stacked together. Each image is exposed for many minutes. Five is a pretty standard exposure time. Special equatorial mounts are used to first locate the object in the sky and then to track it as the Earth rotates throughout the night. Remember, the Earth is spinning at an incredible rate. The mount must counter rotate the telescope and camera at exactly the same speed, while staying pointed at the exact place in space where the first image started or else the stars and the deep space object will appear as light trails across the sky.

Astrophotography cameras usually image in monochrome. Filters are used to capture the different gases found in space – most commonly Hydrogen Alpha, Sulphur and Oxygen. Special processes are then used to map the monochrome images of different gases to the red, green and blue color channels to create a color image.

WHAT IS A NEBULA?“Nebula” comes from the Greek word for “cloud.” A nebula is a giant, interstellar cloud of gas and dust in space, formed from stars. Nebulae have varying compositions depending on how they were formed and where they are. Most nebulae are enormous in size. Some are even hundreds of light-years in diameter. These giant regions of space often have star forming characteristics. In other words, when you look at the bright center of a nebula, you are looking at where stars are being born!

Most nebula are also incredibly far away… as in thousands of light years away. A light year is the distance light can travel in a year at the speed of light – nearly 6 trillion miles. So if a nebula is say , 5,000 light years away, it is 5,000 x 6 trillion miles away. The light the camera captures on any given day took 5,000 YEARS to reach Earth. When you look at the resulting image, you are literally looking into the past 5,000 years!