Night Sky Photography Techniques

Starting tips and techniques to capture amazing night time photographs. This information will help you to grow your skills and make progress where night photography is concerned.  

1. Manual focus:

Manual focus is crucial for astrophotography because autofocus systems often struggle in low light. Set your lens to manual focus and turn the focus ring to infinity. However, many lenses focus slightly before or after the infinity mark, so fine-tuning is necessary. Use your camera's live view feature, zooming in on a bright star or distant light. Adjust focus until the star appears as a sharp point of light. Some photographers use a Bahtinov mask for precise focusing.

2. Aperture:

Using the widest aperture (lowest f-number) allows your lens to gather the most light, which is crucial for capturing faint stars and the Milky Way. However, some lenses perform better when stopped down slightly. For instance, a lens that's softest at f/1.8 might produce sharper stars at f/2.0 or f/2.2. Experiment to find the sweet spot between light gathering and sharpness for your specific lens.

3. ISO:

High ISO settings are necessary to capture enough light for a well-exposed image. Start around ISO 3200-6400 and adjust based on your camera's performance. Modern full-frame cameras can often push to ISO 6400 or even 12800 while maintaining acceptable image quality. Remember, a "noisy" but well-exposed image is often better than a clean but underexposed one, as noise can be reduced in post-processing.

4. Shutter speed:

The goal is to use the longest possible exposure without causing star trailing. The "500 Rule" (500 divided by focal length) provides a starting point, but it's not perfect, especially for high-resolution sensors. For instance, with a 14mm lens on a full-frame camera, you might start with 35 seconds (500/14). However, you may need to shorten this to 25 seconds (using the 350 Rule) or even less for pin-sharp stars. Always check your results and adjust accordingly.

5. White balance:

A white balance around 3800K-4300K often produces natural-looking night sky colours. However, the "correct" white balance is subjective and can vary based on conditions and artistic intent. Shooting in RAW allows you to adjust white balance in post-processing without quality loss.

6. Composition:

Including foreground elements adds depth and scale to your images. Look for interesting shapes or silhouettes. The Milky Way can serve as a natural leading line, guiding the viewer's eye through the frame. Consider using the rule of thirds or golden ratio for pleasing compositions. Remember, compelling foreground elements can elevate your image from a simple star photo to a captivating landscape.

7. Long exposure noise reduction:

This in-camera setting takes a second "dark frame" exposure with the shutter closed, then subtracts this from your image to reduce noise. While effective, it doubles your exposure time, which can be problematic for capturing short-lived phenomena or when taking multiple exposures for stacking. It's often better to turn this off and deal with noise in post-processing.

8. Image stabilization:

When using a tripod, turn off lens or in-body image stabilization. These systems can ironically introduce blur when the camera is already stable, as they may try to correct for non-existent movement.

9. Shoot in RAW:

RAW files contain much more data than JPEGs, allowing for greater flexibility in post-processing. This is especially important in astrophotography, where you often need to make significant adjustments to exposure, white balance, and colour.

10. Use a sturdy tripod:

A stable platform is crucial for sharp images during long exposures. Invest in a sturdy tripod that can handle the weight of your camera and lens. In windy conditions, you might need to weigh down your tripod or use a lower angle to increase stability.

11. Remote shutter release or timer:

Even the small vibration from pressing the shutter button can introduce blur in long exposures. Use a remote shutter release or your camera's built-in timer (2 seconds is usually sufficient) to avoid this.

12. Take multiple exposures:

Taking multiple shots of the same scene allows for various techniques:

- Noise reduction through stacking: Combine multiple exposures to average out random noise.

- Creating star trails: Stack exposures to show star movement over time.

- Exposure bracketing: Capture different exposures for the sky and foreground to blend later.

13. Light painting:

Use a flashlight or other light source to subtly illuminate foreground elements. This technique requires practice to achieve natural-looking results. Start with very low power and build up gradually. You can light paint in a single long exposure or in a separate exposure to blend later.

14. Plan your shoot:

Apps like PhotoPills, Stellarium, or Star Walk can help you plan when and where the Milky Way will be visible. They can also show you moonrise/moonset times and the position of other celestial objects. Planning ahead ensures you're in the right place at the right time for the best possible shot.

15. Focusing technique:

Accurate focus is critical. Use your camera's live view, zooming in on a bright star or distant light. Manually adjust focus until the star is a sharp point. Some photographers use a focusing aid like a Bahtinov mask for even more precision. Once you've achieved focus, you can mark the focus point on your lens with tape or a marker for future reference.

16. Shoot during new moon:

Moonlight can wash out the stars and Milky Way. The darkest skies occur during the new moon phase. However, a crescent moon can sometimes provide pleasing lighting for landscape elements without overpowering the stars.

17. Consider blending exposures:

The dynamic range required to capture both a bright sky and dark foreground often exceeds what a camera can capture in a single shot. Taking separate exposures for the sky and foreground, then blending them in post-processing, can result in a more balanced final image.

18. Lens heater:

In humid conditions, lens temperature can drop below the dew point, causing condensation on the front element. This ruins image quality. A lens heater (essentially a warm strip that wraps around the lens) prevents this. DIY solutions using hand warmers can also work.

19. Experiment with panoramas:

Stitching multiple shots into a panorama allows you to capture a wider field of view than your lens allows, or to create ultra-high resolution images. This technique requires careful planning and execution to ensure proper overlap between frames.

20. Post-processing:

Specialized software like Starry Landscape Stacker, Sequator, or Deep Sky Stacker can align and stack multiple exposures, reducing noise and bringing out faint details. General editing software like Adobe Lightroom and Photoshop are useful for adjusting exposure, colour, and sharpness. Some astrophotographers use plugins like Astronomy Tools or Starnet++ for advanced editing techniques.

Remember, mastering these techniques takes time and practice. Don't get discouraged if your first attempts aren't perfect. Each outing is a learning experience, and the skills you develop will lead to increasingly impressive results.