Astrophotography

Astrophotography v astronomy

Astrophotography differs from astronomy in that it is mainly concerned with photographing and imaging celestial objects using cameras and telescopes. Astrophotography is sometimes referred to as observational astronomy and astronomical imaging. Astronomy in the main is a study of celestial objects using mathematics, physics, chemistry, and other varied forms of technical imaging to understand and explain their origins and evolution in a scientific approach.

Techniques

There are several techniques you can employ to image objects in the night sky. Most involve the use of a tripod to stabilise the photograph due to long exposures being required for most shots. Depending on the techniques and the photography equipment used night sky astrophotography photographs could be anywhere from a few images to a stacking blend of hundreds of images taken over many hours or nights.

A basic equipment setup would be a camera with wide angle lens, mounted onto a tripod with a remote trigger connected to the camera to set off the shutter. A remote trigger is important because just the act of pressing the shutter button manually on the camera can introduce some shake and cause the resultant image to be blurry.

There are various techniques you can use when photographing the night sky. If you want to photograph the stars in sharp detail, then your shutter speed should be no longer than 25 seconds.

Any longer and you’ll introduce too much blur in the stars due to the rotation of the earth. Experiment with ISO, shutter speed and aperture and see what results you get. There’s a lot of tricks and ideas you can gain from right across the Internet that you can study to get the best astrophotography photographs out of your camera.

Move away from bright city lights

The darker the sky the more objects you’ll be able to see both with your eye and your camera. The best place and time to image the night sky is away from the glow of bright city lights and on nights where the moon hasn’t risen. Websites such as www.timeanddate.com will list the sun and moon rise times and date, from where you’ll be able to determine moonless dark sky nights.

If you want to create photographs with star trails, then you’ll need much longer shutter speeds. Most DSLR cameras will allow the shutter to be open for up to 30 minutes on Bulb Mode.

The earth rotates 360 degrees in 24 hours, so a 30-minute exposure will result in star trails with a rotation angle of 7.5 degrees (360 degrees / 24 hours x 0.5 hours = 7.5 degrees). The photo will show a nice star trail but to create longer star trails all you need to do is take more photographs – as many as you would like in the time you have whilst on your astrophotography adventure.

You’ll then need to stack your photos in a program such as Adobe Photoshop and use the “lighten” blending option to merge all photos. Google: stack star trails using lighten mode in photoshop and you will find a plethora of tutorials.

Deep sky astrophotography

Deeper night sky objects such as galaxies, nebulae, and the surface details of planets such as Mars, Jupiter and Saturn require additional equipment such as a telescope, tracking mount and telescope camera mounting accessory to attach your DSLR directly to the telescope

Depending on your budget the cost of a basic setup can range from around a thousand dollars up to the more advanced computerised telescopes, trackers, filters, and astrophotography stacking software that can total in the tens of thousands of dollars.

Remember though, it is like any other hobby in that you can start out small and at low cost, then increase your budget and the quality of your equipment over time as you become more hooked on astrophotography.

Astrophotography is built for exposure

Astrophotography photography is an incredibly unique genre of photography. There are a lot of technical considerations required to produce the best images. They are recognised as being mesmerising, humbling and beautiful. So upload your greatest astrophotography photographs to your website and to your social accounts such as TikTok, Facebook and Instagram to gain good exposure of your night sky astro work.