AviStack is a freeware Windows program that allows you to process lunar, solar and planetary images. It relies on thousands of reference points to compensate for viewing-related distortions. This means, you can detect even the smallest details in high-resolution photographs.

General notes

After launching the tool, you will be presented with three windows, each with its own functionality. You can choose and open the movie you wish to process via the in-built file browser. Next, the selected clip will appear in the center frame. Here, you are able to pick a desired frame and process it. If the resulting image is too noisy, you may use special software like Noiseware Professional to remove it.

In addition, you have the option to toggle the quality analysis checkmark to make the application automatically detect the best images using sharpness and brightness. It is also possible to set the percentage of the images that will be processed.

Performance

Despite the considerable amount of reference points, the utility is quite fast. It also enables you to process files in batches for all time consuming processing steps. All you need to do is prepare all settings necessary to stack the film, save these settings and start the procedure. Depending on the number of items it may take from several minutes to a full day.

Features

free to download and use;
allows you to process lunar, solar and planetary images;
compatible with modern Windows versions;
it is possible to toggle automatic detection of best samples;
you can process multiple items simultaneously.