I’m going to show you how I get Pixel 8a–level night and astrophotography results from a budget Android phone by shooting RAW and manually stacking frames. I do this on phones that don’t have Google’s sophisticated multi-frame pipeline, and the trick is simple: capture many short RAW exposures, then align and stack them to dramatically reduce noise and extract faint stars and sky detail. The workflow is hands-on but repeatable, and it works whether you’re using a £150 phone or an older midrange device.

Why stacking RAW frames beats single long-exposure tricks

Modern flagship phones like the Pixel 8a do incredible things with multi-frame processing and machine learning. If your phone doesn’t have that software magic, you can mimic parts of it yourself. Shooting a single very long exposure on a cheap sensor produces lots of heat noise, hot pixels, and weird color casts. Stacking many shorter RAW frames accomplishes three useful things:

  • It averages out random noise (improving signal-to-noise ratio) without amplifying sensor heat artifacts.
  • It preserves linear RAW data so you can perform careful exposure and white-balance adjustments post-capture.
  • It allows you to reject frames with airplane trails or passing cars and to add dark-frame subtraction for sensor artifact reduction.

    • What you’ll need (hardware and software)

    Here’s what I use and recommend — you don’t need anything exotic.

  • A budget Android phone that can save RAW/DNG (many phones do; look for “RAW” or “DNG” in camera settings). If your stock app can’t, use Open Camera or Camera FV-5 or ProCam X which enable RAW capture and manual controls.
  • A sturdy tripod and a phone clamp. No tripod = no astrophotography worth saving.
  • An intervalometer app or built‑in interval shooting in your camera app (Open Camera has one). This automates grabbing dozens of frames.
  • A cable or Wi‑Fi method to transfer DNG files to a computer (stacking on desktop will give the best results). I usually use USB + Android File Transfer or an SD card on other phones.
  • Stacking software on your computer: I recommend Siril (free, cross-platform), Sequator (Windows, free), or DeepSkyStacker (free, Windows). These align and average frames and can handle dark frames. For Mac users, use Siril or AstroStakkert!, and StarStax for star trails.
  • Optional: Lightroom/RawTherapee for per-frame adjustments and final editing.

    • Capture settings — how I shoot

    Everything starts at capture. The key is RAW, manual focus, and consistency between frames.

  • Mode: Manual/Pro mode or Open Camera set to RAW (DNG) output.
  • Focus: Manual. Switch to infinity and then fine-tune by zooming on a bright star or distant light and using live view. If your app has focus peaking, use it.
  • Shutter & ISO: Use several short exposures instead of one long one. My go-to approach: 20–60 frames at 6–12 seconds each, ISO 800–1600. The exact shutter speed depends on your lens/field-of-view and the “500 rule” for stars: max exposure ≈ 500 / (full-frame-equivalent focal length). On phones the focal length is tiny so you can often use 8–12s without trailing.
  • White balance: Set it to a fixed Kelvin value (e.g., 3500–4000K) so all RAW frames are consistent — you’ll tweak white balance in post.
  • RAW only: Turn off JPEG or at least make sure RAW is saved. JPEGs are already processed and limit stacking benefits.
  • Dark frames: If you have time, capture a set of dark frames — same exposure settings but with lens cap on. Take 10–20 dark frames, which helps remove hot pixels and sensor pattern noise during stacking.
  • Intervalometer: Program it to shoot back-to-back frames with minimal delay. For example, 40 frames x 8s = about 6 minutes capture time plus buffer between shots.

    • Example session I run (practical)

    When I head out, I do these things in order:

  • Mount phone on tripod and level; compose with a little foreground if I want context.
  • Enable airplane mode to avoid interruptions and glowing notifications.
  • Set camera to manual focus and lock it after checking a bright star at max zoom.
  • Set RAW, manual shutter 8s, ISO 1000, WB 3700K, and start intervalometer for 40–60 frames.
  • After the sequence, take 10 dark frames (same settings, lens cap on) and a few bias frames if your stacking app supports them (shortest possible exposure with cap on).

    • Transfer and stacking — step-by-step on desktop

    I normally transfer DNG files to my PC and use Siril. Sequator is slightly easier for Windows users so I’ll summarise both workflows.

  • Transfer: Copy the sequence folder (RAW DNGs) plus dark frames to your computer in one folder.
  • Preprocess (optional): I sometimes open a handful of frames in RawTherapee or Lightroom to check exposure and white balance. Don’t apply heavy noise reduction — you want linear data for stacking.
  • Siril workflow:
  • Open Siril; convert DNGs to FITS (Siril has a converter).
  • Register (align) the light frames — Siril identifies stars and aligns accurately even for wide-angle shots.
  • Stack using median or average method; include dark frames for subtraction. Use normalization to keep levels consistent.
  • Stretch the stacked image using Siril’s Histogram Transformation — this pulls up faint nebulosity and sky glow.
  • Export to TIFF and finish adjustments in Photoshop or Lightroom (curves, color balance, selective noise reduction).
  • Sequator (Windows, simpler):
  • Open Sequator, load the lights (your DNGs) and darks.
  • Choose “Star Stacking” or “Light Pollution Reduction” options if needed.
  • Press Start — Sequator aligns and stacks automatically and produces a TIFF you can open in Lightroom for finishing.

    • Post-processing tips to get that Pixel-like pop

    Stacking gives you a low-noise master — the rest is tasteful editing.

  • White balance and tint: Tweak to a neutral or slightly cool tone for space images; many phones bias toward warm orange when shooting night scenes.
  • Curves and contrast: Gentle S-curve increases contrast without crushing faint stars. Use local contrast or clarity sparingly — too much can make the sky grainy.
  • Noise reduction: Apply global noise reduction on the sky, but mask out stars so they remain sharp. Use luminance denoise first then chroma denoise for color speckles.
  • Sharpening: Light sharpening on small details; for stars, a very small radius and mask so only cores are sharpened.
  • Remove residual hot pixels: Spot-heal any stubborn hot pixels you see.

    • Common problems and how I fix them

    Here are issues I run into and quick fixes.

  • Trailing stars: Shorten exposure or reduce focal-length equivalent by avoiding digital zoom. Increase frame count instead.
  • Plane or satellite trails: Exclude those frames during stacking or use a median stack that removes outliers. Siril and Sequator can help reject bad frames.
  • Bright foreground blown out: Use a separate exposure or a short-exposure bracketed foreground and blend in Photoshop (simple exposure mask).
  • Color casts and weird gradients: Apply gradient removal tools in Siril or local gradient correction in Lightroom. Light pollution filters in Sequator can help.

    • If you follow this recipe—steady tripod, RAW capture, 20–60 short frames, dark frames, and desktop stacking—you can reliably get night and astro images that put many single-exposure phone shots to shame. It’s not instantaneous like Pixel’s software, but the control and final image quality are often superior, especially when you target faint stars and low-contrast Milky Way detail.