Astrophotographers combining multiple exposures of galaxies, nebulae, and star clusters can use DeepSkyStacker to build a cleaner image from a capture session. It registers stars across the frames, aligns the images, and stacks them to reduce noise and bring out faint detail. The workflow also accommodates calibration frames that help correct capture-related artifacts.
Sort light and calibration frames
Add the light frames that contain the target, then place calibration images in their matching groups: dark, flat, or bias/offset. DeepSkyStacker uses these frame types during processing to correct issues such as sensor noise and uneven illumination. It can read common camera RAW formats as well as FITS, TIFF, and JPEG images.
Register stars before stacking
Registration analyzes the images for stars and matches their positions across the session. This alignment lets the frames combine even when the camera shifted slightly between exposures. After registration, select the frames to include and start the stack; the program combines their image data to improve the signal-to-noise ratio and reveal faint structure.
- Use light frames to build the image of the target.
- Include dark, flat, and bias frames when available.
- Choose a stacking method in the stacking parameters; options include average, median, and kappa-sigma clipping.
Choose how the frames combine
The stacking method affects how DeepSkyStacker handles pixel values across aligned exposures. Average combines the values directly, while median selects the middle value; kappa-sigma clipping can reject outlier values such as those caused by transient noise. The best choice depends on the data in the session, so different methods may produce different results from the same frames.
The resulting stack is a starting image for further adjustments such as color, contrast, and sharpening in an image editor.
Pros
- Registers stars and aligns exposures automatically
- Combines light frames with dark, flat, and bias frames
- Accepts common camera RAW files, FITS, TIFF, and JPEG images
- Offers multiple stacking methods, including kappa-sigma clipping
System requirements: Windows 10, Windows 11 · 64-bit only
What does DeepSkyStacker do with astrophotography images?
It detects and aligns stars across multiple exposures, then stacks the frames to reduce noise and reveal more detail.
What are dark, flat, and bias frames for?
They are calibration frames that DeepSkyStacker can combine with the light frames to correct capture-related noise and illumination variations.
Can DeepSkyStacker process camera RAW files?
Yes. It supports common camera RAW formats along with FITS, TIFF, and JPEG images.