Capture RAW images. Import them to Lightroom, choose one and edit to taste. Then synchronize remainder of images to the edited image.
- Batch export all images as JPEGs to their own folder.
- Using Photoshop, Select File > Scripts > Load Files into Stack.
- Select all the images in the pop up menu and click OK.
- In the Layers window, click the top image and select all but the last image.
- Change from “Normal” blend mode to “Lighten.”
- Select Layer > Flatten image to merge the layers.
- Select File > Save to save the star trails image.
Try to start shooting halfway through the evening’s nautical twilight. Set exposure for dark sky.