A professional astrophotographer has shared his detailed technique for creating stunning composite images that showcase multiple satellite trails streaking across the night sky. Matt Jackson's image "Big Brother is Watching You" earned high commendation in the People and Space category of the 2024 Astronomy Photographer of the Year competition, demonstrating an innovative approach to capturing the increasingly crowded skies above Earth.
Since the Soviet Union launched Sputnik 1 into low Earth orbit in 1957, thousands of satellites have begun crowding the skies over our planet, creating a challenge that anyone shooting night-sky timelapses will immediately recognize. Jackson, who has spent much of the past five years creating night sky photography, developed this technique specifically to showcase these satellite trails in a single, comprehensive composite image.
The timing of the capture proved crucial to the project's success. Jackson photographed the frames for this image during the early evening hours, when satellites are most visible. This optimal viewing window occurs a few hours before sunset and after sunrise, when the sun sits low enough to darken the skies while maintaining an angle that allows its light to strike and illuminate the satellites as they pass overhead.
The technical specifications for the timelapse were carefully chosen to maximize satellite visibility. Jackson's setup comprised one full hour of six-second exposures, shot at f/1.4 aperture and ISO 5000. These settings allowed him to capture the faint satellite trails while maintaining image quality throughout the extended shooting session.
Before creating the actual timelapse composite, Jackson batch-edited all frames using Adobe Lightroom's Develop module. He began by editing a single frame to his preferred specifications, increasing the prominence of each satellite by moving the Contrast, Whites, and Dehaze sliders to the right while decreasing the Shadows, Blacks, and Highlights settings. Once satisfied with the adjustments on one frame, he applied these settings to all remaining frames by selecting them all using Ctrl+A and syncing the settings with Ctrl+Shift+S, checking all settings before clicking Synchronize.
After processing, Jackson saved these edited frames as "Satellite images" in preparation for the Photoshop compositing phase. Additionally, he selected and separately edited a background image for the composite, ensuring that the empty sky areas appeared lighter than the sky in the satellite images. This brightness difference would prove essential for easier compositing of the satellites with the background image.
The Photoshop workflow required sophisticated layer management techniques. Jackson loaded all the Satellite images as a stack in Photoshop by navigating to File > Scripts > Load files into stack and selecting all the processed files. He set the Layers blending mode to Lighten to allow the bright satellite trails to show through multiple layers effectively.
To manage the large number of layers efficiently, Jackson merged the layers into groups of five. He accomplished this by selecting five layers at a time, right-clicking, and choosing Merge Layers from the context menu. This process reduced his layer count from 515 individual layers down to a more manageable 103 merged layers. Each satellite trail then appeared as a streak composed of five distinct lines, making the individual satellites much easier to locate and work with during the masking process.
The masking phase required meticulous attention to detail. Jackson began by deactivating all layers except the bottom one by unchecking the eye symbol next to each layer. To make the masking process more visible and accurate, he created a bright pink-colored fill layer by clicking Layers > New Fill Layer > Solid Color and selecting a vibrant pink. This colored background made it immediately obvious which satellites were being masked in each layer.
Using Photoshop's Brush tool, Jackson carefully masked each satellite streak by clicking and dragging the brush over every individual trail visible in that layer. The pink background layer simplified this process by providing high contrast against the satellite streaks. Once he finished masking all satellites in a layer, he inverted the mask by clicking the mask icon and pressing Ctrl+I simultaneously. This inversion technique masked everything except the satellites in that specific layer, proving much more efficient than attempting to mask out everything other than the satellites using the brush tool.
Jackson repeated this masking process for each of his 103 layers. He streamlined the workflow by clicking and dragging the pink fill layer to each subsequent layer above, clicking the eye symbol to reactivate that layer, and then clicking the mask icon to begin masking the satellites visible in that particular layer. This systematic approach ensured consistent results across all layers while maintaining efficiency throughout the lengthy process.
Once all layers were properly masked, Jackson deleted the pink fill layer and changed all layer blending modes back to Lighten. To complete the composite, he loaded his carefully selected background image at the bottom of the layer stack using File > Open, then copied it with Ctrl+C, pasted it with Ctrl+V, and click-dragged it to the bottom position in the layer hierarchy.
The strategic choice to make the background image's sky brighter than the satellite images proved its worth during the final compositing phase. This brightness difference helped effectively conceal any masking artifacts that might appear around each satellite streak, creating a cleaner and more professional final result.
Jackson completed his image with final adjustments using Photoshop's Camera Raw Filter, accessible through Filter > Camera Raw Filter. These final edits allowed him to fine-tune the overall appearance, contrast, and color balance of the completed composite image.
While acknowledging that this process doesn't account for natural variations in satellite visibility that result from seasonal changes and varying atmospheric conditions, Jackson emphasizes that the technique consistently creates visually striking and beautifully arresting images. He offers three essential tips for photographers attempting similar projects: use short exposures between 2.5 and 6 seconds, employ a wide aperture around f/1.4, and set a high ISO around 5000 to effectively capture the timelapse sequences. He also recommends using a bright-colored fill layer below the active layer to make masking easier and suggests using the square bracket keys to quickly adjust brush size during mask refinements.
