Why I Do Astrophotography

I find the universe fascinating! To get my head around the fact that everything that can be seen and everything that can't be seen all originated from the same source, a singular event that happened 13.7 billion years ago, the big bang. The universe is an enormous place and even the nearest stars are measured at a distance of multiple light years. The cosmos is the ultimate art gallery as it is full of exotic objects that are so far away they cannot be seen with the naked eye, a telescope is required. I have always enjoyed photography and know my way around a camera, astrophotography was therefore a natural step marrying my two loves of astronomy and photography. There is also the technical challenge of photographing an object that is millions of light years away that most people have never seen.

                                                                  The Unique Challenges of Astrophotography

Astrophotography is a difficult challenge,  it is not a matter of just pointing and clicking a camera in the direction of a celestial object. Astrophotographers push their equipment to the limit. A good astrophotographer has to understand astronomy, optics, photography and how to use the plethora of other equipment that is required.

The challenges of astrophotography are very different from that of terrestrial photography.  A terrestrial photographer can have large camera lenses, but an astrophotographer's camera lens is the telescope. Terrestrial photographers can use 2 to 10X magnification (zoom lenses), but it is not uncommon for astrophotographers to use 50 to 1,000X magnification. Terrestrial photographers use very short exposure times usually in hundredths of a second, astrophotographers have very long exposure times that can be in hours rather than minutes or seconds. However the main difference between terrestrial and astrophotography is that astrophotographers have to compensate for the rotation of the Earth which is something that would never cross the mind of a traditional terrestrial photographer.

                                                          The Two Essentials To Successful Astrophotography

As I have already mentioned astrophotography is a difficult challenge with many things to go wrong, however there are two critical essentials you must have right for successful results. The first is accurate Polar Alignment and this can be achieved by using the Drift Method. The more accurate the polar alignment achieved the longer exposure times can be used, which means more light is captured and therefore more detail in the final photograph. The second essential is achieving Perfect Focus, this is easier said than done as often the celestial object being photographed is so dim and hard to see making it very difficult to achieve focus (in astrophotography the camera is always focused to infinity). There are various tools to help an astrophotographer achieve focus (eg Stellar STI Pro) but taking medium length exposures using a DLSR and then checking if any finite adjustments need to be made will eventually ensure perfect focus. This does take time but it is a proven method in achieving perfect focus, without it all that will be achieved is a very long exposure of a blur.