Imaging the moon is a great way to get started with astrophotography as you don’t need a lot of equipment. They best approach is to use lucky imaging, where you capture a video of the moon and not a picture. I first use FireCapture to capture a single video per filter of at least 500 frames. What you will see is that portions of the images will go from clear to blurry, almost like you are looking at the moon through water
To make the lucky imaging process work, I need to grab those points in time where the clarity of the image is extremely high and discard lower quality sections. AutoStakkert! makes the moon stacking process extremely easy.
The first part is to have AutoStakkert! analyze the video file.
Once the video file is loaded, we need to set the following:
- Surface Image Stabilization: Because we are dealing with the moon, we need to stabilize the image for the surface. Autostakkert will display a green box to use as a reference point. This green box must be place on a bright portion of the moon or else Autostakkert will be unable to match between frames.
- Local/Global: Using local will allow AutoStakkert to determine the quality for each alignment point instead of the image as a whole. For lunar imaging, local works better because it takes up so much of the field of view. You will end up with multiple alignment points, with different quality values for each.
- Image Calibration: Depending on your setup, you might need to load a master flat, which will help to remove dust donuts from your imaging rig. I find this is more important when imaging through a telescope with R, G and B filters. With a simple DSLR setup, this isn’t as important. Without this, I end up with rainbow halos corresponding with dust on my lens. To create a master flat, use the following PixInsight process.
Once set, hit the Analyze button.
Once the video file has been analyzed, we can let AutoStakkert create the best possible image by stacking the best frames.
- Frames to Stack: In deep sky astrophotography, we need more frames to increase the signal and decrease the noise. For lunar imaging, our signal is extremely strong. We only want multiple frames for quality. I typically only use 10% of the frames for a lunar image. However, there are 4 placeholders for number of frames and % of frames. Each box that has a value will be a new end result, allowing you to quickly compare which approach is better. Initially, try 10%, 25%, 50%, 75%.
- Sharpened: AutoStakkert can create a sharpened final image in addition to the baseline image. I often select this as a good starting point for futher image processing.
- Alignment Points: In the image window, we need to place a grid of alignment points. I often use 104 alignment points for lunar imaging as it creates a slightly better final image than 24, 48 and 200. Make sure that no alignment points appear outside of the lunar image.
Once these settings are complete, we can Stack our video into a single image.
When you compare a single image, an un-sharpened image and a sharpened image, you can easily see the value the AutoStakkert provides for lunar imaging.