What is astrophotography and what photo equipment do you need?

Astrophotography is a specialized photographic discipline that involves taking pictures of objects in the night sky. It ranges from capturing a photo of the moon or a star-speckled view in the backyard to multiple long exposures of deep sky objects.

While it even includes images captured via a computer link to a distant telescope in a distant observatory, for most photographers it is about using their own camera to photograph the sky at night.

The most accessible form of astrophotography requires nothing more than a DSLR or mirrorless camera, a reasonably fast lens, and a tripod. If your area suffers from light pollution – where street and city lighting spreads upward and reflects off airborne dust and water droplets to create a hazy glow of unwanted light – then it is worth going to a certified “dark sky area” or at least the rural countryside.

Photograph the moon

If you have a longer lens – like a zoom that extends up to 300mm or more, then a full moon photo is a must on the budding astro checklist, and is really easy to pull off. Simply set your exposure mode to Manual and set the ISO to 200, the aperture to f / 8, and the shutter speed to 1/250 sec. Take a photo using AF to focus on the moon and check your results on the screen.

The atmospheric conditions will vary the brightness, so if your photo is too dark, open the aperture to f / 5.6 and resume to brighten things up. You’ll need a massive focal length of around 1200mm to fill the frame – beyond most people’s budget – but as long as you get a sharp result at 300, 400, or 500mm, you can crop. and still get a decent picture.

Shoot starry skies

Another great project that doesn’t require a highly specialized kit is a wide-angle shot of the starry sky, or if you’re lucky, the Milky Way in an arc above a landscape. If the Earth wasn’t moving, you could just take a long exposure to let the darker stars ‘burn’, but unfortunately the Earth’s rotation will cause the stars to register as short trails (or star trails) if you keep shutter open for more than 20-30secs. For this reason, you need to make your sensor very sensitive to light, so dial an ISO of 1600 or 3200 and use your widest aperture, such as f / 2.8. Again, use M mode and try shutter speeds of 20 and 30 seconds.

Focusing can be tricky, and your best bet is to use manual focus with live view enabled. Zoom the screen up to 10x and scroll until you are centered on a star or group of stars. Then slowly rotate the focus ring back and forth until the image is the sharpest.

Star tracker brackets

If you want to shoot constellations, the same goes for wide angle shots over the star field, but you will need a longer focal length, such as 50-100mm (depending on the size of the star field). constellation you capture). Keep in mind that the longer the focal length, the more you magnify the scene and the shorter the shutter speed must be to prevent stars from turning into streaks.

For shots of deep sky objects like nebulae, galaxies, and star clusters, you need much longer exposures for them to record because they are very faint. It is also necessary to take several shots and stack them to improve the signal (the light) compared to the background noise (the electronic gain of the camera). This means that you have to follow the sky for a long time to counter the rotation of the earth, and it requires a specialized kit like a smooth and precise motorized equatorial mount that is configured with precision.

In addition to that, a lens long enough to enlarge them (like a telescope) and an eyepiece adapter for your camera will be needed. This takes you into a more specialized area of ​​deep sky astrophotography that deserves further research if you are hooked after trying the more accessible projects.

Read more:

• Best star tracking camera mounts
• The best light pollution filters
• Best camera for astrophotography
• The best lenses for astrophotography