Long Exposure Astrophotography Tips: Capture Stars & Night Skies

The night sky is an exciting canvas filled with celestial wonders waiting to be marvelled at and photographed. Astrophotography — the art of photographing these wonders — allows us to gaze deeper into the cosmos and reveal details invisible to the naked eye. But astrophotography is a unique discipline, requiring specialised techniques to overcome the challenges of low-light conditions.

Long exposure is one of the most powerful tools in an astrophotographer's arsenal. By keeping the camera shutter open for extended periods, we can gather more light, revealing the faint stars, nebulae, and galaxies that would otherwise be lost in darkness. However, long exposures also introduce challenges like star trails and noise.

Ted's is passionate about helping you capture the magic of the night sky. In this blog post, we'll delve into essential long-exposure astrophotography tips to help you along.

• Long Exposure Astrophotography Gear Checklist
• Master these Settings for Great Astrophotography
• Additional Astrophotography Tips
• Products to Take You to Infinity and Beyond

Long exposure astrophotography gear checklist

To capture the beauty of the night sky, you'll need the right tools to overcome the challenges of long exposures. Here are some essential pieces of equipment.

• Mirrorless cameras with dedicated star modes: For astrophotography, a capable camera is crucial. Mirrorless cameras like the Nikon Z8 boast impressive low-light capabilities and features like a "Starlight mode" that optimises settings for long exposures of starry skies. Other excellent options include the Sony A7R IV, with its exceptional dynamic range, and the Canon EOS R8, with its fast and accurate autofocus.
• Wide-angle lenses: A wide-angle lens is essential to capture the vastness of the night sky. Lenses like the Sigma 14-24mm f/2.8 Art or the Sony FE 14mm f/1.8 GM offer a broad field of view, perfect for capturing expansive starfields or the Milky Way.
• Sturdy tripod: Camera shake is the enemy of long-exposure astrophotography. A sturdy tripod is vital to ensure your camera remains perfectly still throughout the exposure. Consider tripods with a good weight capacity to handle the weight of your camera and lens.
• Remote shutter release: Even the slightest touch on the camera can cause vibrations during long exposures. A remote shutter release eliminates this risk, allowing you to trigger the shutter without physically touching the camera.

Master these settings for great astrophotography

Once you have the right gear, it's time to dial in the perfect settings for your long exposures. Here's a breakdown of the key settings to consider.

• Aperture: Open your aperture as wide as possible (low f-number) to gather the most light during the exposure. Lenses like the Sigma 14mm f/1.8 DG HSM Art, with its wide f/1.8 aperture, excel in low-light conditions.
• Shutter speed: This is where the magic of long exposures happens. Experiment with different shutter speeds, starting with around 15–30 seconds and adjusting based on the desired brightness and level of star trails. Remember, longer shutter speeds will result in more prominent star trails.
• ISO: While a higher ISO increases light sensitivity, it also introduces noise. Start with a low ISO (around 100) and adjust gradually if needed to achieve a balanced exposure without excessive noise. Cameras like the Sony A7R IV boast impressive high ISO performance, allowing you to push the limits without sacrificing image quality.
• Manual focus: Since autofocus struggles in low light, switch to manual focus. Use the live view function on your camera screen to achieve precise focus on a bright star.

Additional astrophotography tips

Beyond the essential gear and settings, these additional tips can help you take your astrophotography to the next level.

• Location, location, location: Light pollution can significantly impact your results. Seek out dark locations with minimal light interference — national parks and remote areas often provide ideal conditions for capturing the night sky.
• The 500 rule: This rule of thumb helps determine the maximum shutter speed before noticeable star trails appear. Divide 500 by the focal length of your lens to get the approximate maximum shutter speed in seconds. This is just a starting point — feel free to experiment with longer exposures for artistic effects.
• Embrace the stacking technique: Capturing multiple long exposures and stacking them in post-processing software can significantly reduce noise and enhance image detail.
• Foreground interest: Include a captivating foreground element — like the silhouette of a tree or a mountain — to add depth and context to your astrophotography composition.
• Practice and experiment: As with any creative pursuit, astrophotography takes practice and experimentation. Don't be afraid to try different settings, locations, and techniques to discover what works best for you.

Products to take you to infinity and beyond

Here's a selection of the best cameras and lenses to help you capture stunning astrophotography images.

Mirrorless cameras

• Nikon Z8 — this high-resolution mirrorless camera boasts a superb 45.7MP FX-format sensor and 8K UHD video recording. Its advanced EXPEED 7 image processor delivers lightning-fast performance, while features like a real-time viewfinder, pre-release capture, and rapid-fire autofocus make it a dream for astrophotographers.
• Sony A7R IV — known for its impressive dynamic range and high ISO performance, the A7R IV features a 61MP back-illuminated CMOS sensor that captures stunning detail and colour. Its rugged, weather-sealed build makes it ideal for outdoor adventures.
• Canon EOS R8 — a portable and powerful mirrorless camera offering full-frame performance in a compact, budget-friendly package. With its 24.2MP sensor, 4K60p video, and Dual Pixel CMOS AF II system, the EOS R8 is perfect for capturing stunning stills and video.

Camera lenses

• Sigma 14-24mm f/2.8 Art — this wide-angle zoom lens is renowned for its high-quality build and optical performance. Its weather-resistant construction and premium optical design make it ideal for capturing sharp, detailed images of the night sky.
• Sony FE 14mm f/1.8 GM — Sony's widest prime lens, the FE 14mm f/1.8 GM is perfect for landscape, architectural, and astrophotography. Its ultra-wide field of view and fast f/1.8 aperture make it exceptional for capturing expansive starfields and the Milky Way in stunning detail.

Long Exposure Astrophotography: Core Techniques Explained

Long exposure astrophotography is the foundation of virtually every stunning night sky image you've ever seen. When your camera's shutter stays open for several seconds — or even several minutes — it collects far more photons of light than your eye ever could, transforming a dark, sparsely dotted sky into a breathtaking tapestry of stars, Milky Way arcs, and glowing nebulae. Understanding the core principles behind long exposure astrophotography is what separates a frustrating night in the field from a memory card full of keepers.

How Long Should Your Exposure Be?

In long exposure astrophotography, exposure duration is a balancing act. Expose for too short a time and you won't gather enough light to reveal faint celestial objects. Expose for too long on a static tripod and Earth's rotation will cause stars to trail across the frame as elongated streaks rather than crisp points of light. The sweet spot depends on your focal length, sensor size, and whether you actually want star trails or sharp stars.

As a starting point for sharp stars without a tracking mount, most astrophotographers work with exposures between 15 and 30 seconds at wide focal lengths. From there, you layer multiple exposures in post-processing — a technique called image stacking — to build up the total light gathered without introducing trailing. This is one of the most powerful strategies in long exposure astrophotography because it reduces noise, recovers fine detail, and produces results that a single ultra-long exposure simply cannot match.

Why Long Exposure Astrophotography Demands Precise Planning

Unlike daytime photography where light is abundant, long exposure astrophotography punishes guesswork. Even a small amount of ambient light pollution, an unexpected passing car, or a slight vibration from the wind can ruin an otherwise perfect frame. Before you shoot, use a light pollution map to find a dark site, check the lunar calendar to avoid shooting near a full moon A lunar eclipse is also worth planning around — check out our tips for photographing a lunar eclipse to make the most of this dramatic night sky event., and always arrive early enough to let your eyes — and your camera sensor — acclimatise to the darkness. Planning apps like Stellarium or PhotoPills allow you to visualise exactly where the Milky Way core will be at any given hour, helping you compose your shot before you even leave the house. Preparation is the difference between a productive night and a wasted one in long exposure astrophotography.

Image Stacking for Long Exposure Astrophotography

Stacking is a post-processing technique where multiple exposures of the same scene are aligned and averaged or combined to reduce random sensor noise while preserving genuine signal from stars and nebulae. Free tools like Sequator (Windows) and Starry Landscape Stacker (Mac) make this accessible even for beginners. For a typical Milky Way shot, capturing between 10 and 20 individual frames and stacking them can dramatically improve the signal-to-noise ratio compared to a single long exposure — giving your images a cleaner, more professional finish straight out of your processing software.

Star Long Exposure Photography: Sharp Stars vs. Beautiful Trails

One of the first creative decisions you'll make in star long exposure photography is whether you want your stars to appear as pinpoint dots of crisp light, or as sweeping circular trails that trace the rotation of the Earth across the sky. Both are legitimate and visually spectacular outcomes — but they require very different technical approaches, and understanding each will unlock a whole new dimension of what's possible after dark.

Capturing Sharp Stars with Long Exposure: The 500 Rule and Beyond

If your goal in star long exposure photography is pinpoint stars, your maximum exposure time is governed by your focal length and sensor crop factor. The widely-used 500 Rule gives you a quick starting calculation: divide 500 by your effective focal length to get the maximum exposure time in seconds before stars begin to trail noticeably. For example, using a 24mm lens on a full-frame camera gives you approximately 500 ÷ 24 = 20 seconds. On a crop sensor camera (APS-C with a 1.5x crop factor), the same 24mm lens has an effective focal length of 36mm, giving you roughly 500 ÷ 36 = 13 seconds.

Many modern astrophotographers prefer the more conservative NPF Rule, which factors in aperture and pixel density for greater precision — particularly useful with high-megapixel sensors where pixel-level star trailing becomes visible even within the 500 Rule's limits. Apps like PhotoPills calculate the NPF Rule automatically once you enter your camera and lens details, making it easy to dial in on location.

Creating Star Trail Long Exposures

Star trail photography is the other side of the coin. Here, you deliberately embrace the Earth's rotation to create long, arcing light streaks across the sky. To create star trails, you have two main approaches: a single very long exposure (often 30 minutes to several hours using Bulb mode) or a sequence of shorter exposures later blended together using dedicated software like StarStaX. The latter approach is generally preferred because it avoids the significant noise build-up and battery drain that accompany extremely long single exposures, and it also protects you against losing an entire session to a single interruption like a passing car or plane.

For the most dramatic star trails, aim your camera toward the south celestial pole (in the Southern Hemisphere, look near the Southern Cross and the pointer stars to locate it). Stars close to the celestial pole produce tight, circular arcs, while stars near the horizon produce longer, shallower curves. Including a compelling foreground — a lone tree, a lighthouse, an outback rock formation — anchors your star trail long exposure and gives the image a strong sense of place that elevates it beyond a simple technical exercise.

Essential Settings for Star Long Exposure Photography

Regardless of whether you're shooting for sharp stars or trails, certain settings form the baseline for star long exposure photography. Start with your aperture wide open (f/1.8 to f/2.8 is ideal) to maximise light gathering. Set your ISO between 1600 and 6400 depending on your camera's noise performance — modern mirrorless cameras from Sony, Nikon, and Canon handle high ISO remarkably well. Always shoot in RAW format to preserve maximum dynamic range for post-processing. Use manual focus and zoom into a bright star on your live view screen at 10x magnification to achieve precise focus, since autofocus systems struggle in low light. Finally, use a remote shutter release or your camera's built-in timer delay to eliminate any vibration from pressing the shutter button — even a small shake during a 20-second exposure will soften your stars.