Best Stacking Software for Astrophotography

DeepSkyStacker is one of the most popular and widely used image stacking programs for astrophotography. It's an essential tool for capturing the beauty of night sky captures, offering a comprehensive set of features that make the process of image stacking accessible to photographers of all skill levels.

The software uses an advanced star detection algorithm to automatically align and stack multiple images of the same deep sky object. This results in a final image that has significantly reduced noise, improved dynamic range, and enhanced detail.

Key Features

• Automatic alignment function for precise star registration
• Dark frame subtraction to remove sensor noise and hot pixels
• Supports light, dark, flat, dark-flat, and bias frame stacking
• User-friendly interface - popular among beginners
• Robust feature set that scales to experienced users

How to Use DeepSkyStacker for Image Stacking

1. Open the software and select the "Open" option to import your images - drag and drop or browse manually.
2. Click the "Register" tab to align the images. Adjust the "Star Detection Sensitivity" slider until stars are accurately detected.
3. Click "Register checked pictures" to start the registration process.
4. Switch to the "Stack" tab. Select your stacking method (e.g. Median Kappa-Sigma Clipping or Average) and customise settings.
5. Click "Stack checked pictures" - DSS will process your images and produce a merged final result.
6. Once stacking is complete, save the output in your preferred format (typically 16-bit TIFF for further processing in Lightroom or Photoshop).

RegiStax 6 is a powerful image stacking tool specifically designed for enhancing your astrophotography images, particularly those captured through telescopes of planetary subjects. It excels at aligning and stacking multiple frames to reduce noise and improve image quality.

One of the standout features of RegiStax 6 is its wavelet processing system, which allows users to selectively enhance the details in their images while minimising noise. This is particularly effective for planetary photography, where fine details such as cloud bands on Jupiter or craters on the Moon need to be brought out.

RegiStax 6 Features and Functions

• Advanced alignment algorithm for accurate multi-frame registration
• Wavelet sharpening system for bringing out fine planetary detail
• A wide range of processing tools for noise reduction, contrast, and brightness
• Supports RAW, TIFF, and JPEG file formats
• Batch processing for handling multiple image sets
• User-friendly interface accessible to beginners and experienced photographers alike

Step-by-step Guide to Image Stacking with RegiStax 6

1. Open RegiStax 6 and click "Select" to load your image frames. Frames should be a video file (AVI/SER) or a stack of individual images.
2. In the Alignment tab, place alignment points on a prominent feature (e.g. a crater or planetary surface detail).
3. Click "Align" to begin the alignment process. RegiStax will analyse each frame for quality.
4. In the Stack tab, set your quality threshold to discard poor-quality frames (typically keep the best 25–50% for planets).
5. Click "Stack" to combine the selected frames into a single result.
6. Use the Wavelets tab to apply sharpening. Start with gentle settings and increase gradually to avoid artefacts.

Bodiam Castle Milky Way: a single shot showing why stacking matters: multiple frames would dramatically reduce this noise.

Starry Landscape Stacker is a popular software used by astrophotographers to create detailed nightscapes. It is specifically designed for capturing landscape scenes under a starry sky, and has gained recognition for its powerful features and user-friendly interface.

The software automatically aligns and stacks multiple images, ensuring the stars are well-defined and the landscape remains sharp. It can differentiate between the sky and the foreground, allowing for more precise stacking and blending of the two elements.

Key Features of Starry Landscape Stacker

• Automatic image alignment and stacking capabilities
• Sky/landscape separation - stacks each region independently
• Noise reduction across all stacked frames
• Adjustable blending settings for control over sharpness and brightness
• Works best with 10+ frames for optimal noise reduction

Tips for Effective Image Stacking with Starry Landscape Stacker

• Capture multiple images of the same scene with varying exposures for a wider dynamic range
• Use a stable tripod and remote shutter release to minimise camera shake between frames
• A wide-angle lens with a large aperture (f/1.8–f/2.8) captures the most light and detail in the Milky Way
• Capture at least 10–15 frames to achieve noticeable noise reduction
• Review frames after import and remove any with movement blur before stacking

Siril is a powerful and versatile image stacking software specifically designed for astrophotography. It offers a range of features and capabilities to enhance your astrophotography images, covering the full workflow from raw calibration through to a processed result.

With Siril, you can process your raw images, align and stack them, and perform various image adjustments to get the best possible results. It supports various file formats, including FITS, TIFF, and RAW. One of the key features of Siril is the ability to handle high dynamic range images and perform advanced noise reduction techniques.

Siril Features and Capabilities

• Full astrophotography processing workflow - calibration, registration, and stacking
• Advanced registration algorithms for precise star alignment
• Supports high dynamic range images and advanced noise reduction
• Compatible with FITS, TIFF, and RAW file formats
• Script-based processing for automating repetitive workflows
• Cross-platform: Windows, macOS, and Linux

How to Use Siril for Image Stacking

1. Open Siril and create a new working directory for your project.
2. Load your calibration frames (darks, flats, biases) in the Preprocessing tab and apply them to your light frames.
3. Use the Registration function to align your calibrated light frames using star pattern matching.
4. Select your stacking method (Median, Mean, Kappa-Sigma Clipping) and set rejection parameters.
5. Run the Stack process: Siril produces a master light frame ready for post-processing.
6. Apply any additional adjustments (background extraction, colour calibration, deconvolution) using Siril's built-in tools, then export in your desired format.

Sequator is a powerful software designed to simplify Milky Way photography for astrophotographers. With its user-friendly interface and advanced features, Sequator provides an effortless way to stack and enhance images of the night sky. It is the Windows counterpart to Starry Landscape Stacker, both tackle the same challenge of separately aligning the sky and ground.

One of the key benefits of using Sequator is its automatic alignment and stacking capabilities. It uses intelligent algorithms to analyse the individual frames and align them precisely, reducing the blurring effect caused by Earth's rotation.

Sequator Software Overview and Benefits

• Automatic sky/ground separation - stacks stars and foreground independently
• Significantly reduces noise in dark sky images
• Supports RAW files from all major camera manufacturers
• Intuitive workflow that gets results in minutes
• Completely free - no licence required

How to Use Sequator

1. Open Sequator and click "Add" to load your Milky Way frames.
2. Designate one frame as the Base Image. This sets the reference composition for the final stack.
3. Draw a ground mask over the foreground area in the base image. Sequator will keep this region sharp and stationary while tracking the star field.
4. Set your output options (brightness, noise reduction level) and click "Stack".
5. Review the final result: stars should be pinpoint sharp, foreground crisp, and noise significantly reduced compared to a single exposure.

Night sky photography over UK landmarks, the kind of results achievable with good stacking technique.

AutoStakkert! (AS!) is a highly regarded image stacking application, primarily used for planetary, solar, and lunar astrophotography. Its lucky imaging approach, capturing thousands of short video frames and keeping only the sharpest, makes it ideal for photographing through the ever-shifting UK atmosphere.

AutoStakkert! Features and Capabilities

• Lucky imaging: analyses frame quality and selects only the sharpest exposures for stacking
• Intelligent quality estimation that accounts for atmospheric turbulence
• Batch processing - handle multiple frame sets simultaneously
• Image enhancement tools for contrast, brightness, and sharpness
• User-friendly interface suitable for beginners

How to Use AutoStakkert! for Image Stacking

1. Open AutoStakkert! and click "1) Open" to load your video file (AVI, SER, FITS or individual frames).
2. Click "Analyse" - AS! will assess the quality of every frame in your video.
3. Set alignment points across the planetary disc. More points = more accurate alignment across different seeing conditions.
4. Set what percentage of frames to stack (typically 10–50% for good seeing; lower percentages = sharper but fewer frames stacked).
5. Click "Stack" - AS! combines the best frames into a single, sharp result.
6. The stacked result is typically then processed through RegiStax 6 for wavelet sharpening as a complementary final step.