AutoStakkert! and Lucky Imaging: The Mathematical Battle Against Atmosphere

PekDar — Fri, 15 May 2020 06:27:12 +0000

AutoStakkert 2

Learn the best settings and a step-by-step process to stack your Lunar light frames in AutoStakkert and achieve sharper, high-resolution Moon images.

The Seeing Problem

Why is a single DSLR photo of the Moon rarely perfectly sharp? The culprit is Earth’s atmosphere. Air masses of different temperatures mix, creating turbulence that acts like lenses with varying focal lengths. This phenomenon is called seeing. In classical photography (long exposures), seeing blurs details. The engineering solution is the Lucky Imaging technique.

Mechanism: Statistics and Video

Instead of a single photo, we record thousands of video frames with very short exposure times (milliseconds). Statistically, within a second, there are moments when the atmosphere “freezes” for a fraction of a time and becomes perfectly transparent. The role of AutoStakkert! is to analyze each of the thousands of frames, grade their quality (sharpness), and select only the “lucky” ones (e.g., the best 10-20%).

At first impression, the AutoStakkert user interface does not seem easy to use. However, after getting to know the key options and understanding how the program works, its interface not more to be a secret. We will go through the stacking procedure, processing sample of Moon light frames, which I collected in the early spring of this year.

PIPP (Planetary Imaging PreProcessor): The Essential Step Before Stacking

PekDar — Wed, 22 Apr 2020 11:20:37 +0000

PIPP astrophotography – Why Not AutoStakkert! Immediately?

After recording a Moon video (in SER, AVI, or other formats), many beginners skip the pre-processing step in PIPP and directly load files into AutoStakkert!. However, PIPP solves critical recording issues that significantly improve the efficiency and quality of the final stack.

Problem 1: Motion and Jitter (Dynamic Tracking)

During video recording, even with a perfectly aligned mount, subtle vibrations, tracking errors (PEC), and object shifts (e.g., the Moon drifting out of the center) occur.

PIPP’s Role: PIPP analyzes each frame and shifts the image so that the key object (e.g., the Moon disk) remains perfectly centered (dynamic centering) and stable in the X and Y axes.
Benefit for AS!: AutoStakkert! performs alignment much faster and more precisely when the target object is not moving chaotically throughout the video.

Problem 2: Optimization and Conversion (Frames Optimization)

Planetary cameras often record video in formats and resolutions that are not optimal for AutoStakkert! (e.g., 8-bit Y8/MONO format).

Conversion: PIPP provides fast and lossless video conversion to the most preferred formats. It allows conversion from uncompressed to efficient formats, as well as converting a monochrome Y8 signal to simulated RGB.
Cropping for Efficiency: PIPP allows for precise cropping of the Region of Interest (ROI). If the entire Moon disk takes up 1000×1000 pixels, but the rest of the frame is a black void, PIPP cuts out this unnecessary black area.

PIPP Step-by-Step

Usage of the PIPP program is relatively simple. It is recommended to follow the step rules – from left to right, going through all the tabs of the program, starting from the Source Files tab and ending with the Do Processing tab. We will go successively through the tabs, processing the Moon with an example light frames that I collected. I will focus only on those options that I need to use. It is not my goal, to describe every available option, that’s why the manual is available on the PIPP page.

Planetary Astrophotography – PekDar – Astrophotography Engineering