Then the 500 rule can be a great guide to calculate the minimum exposure time you should use for the individual exposures that will make up your Star Trail image.
Sometimes though, trailing stars might be exactly what you want to capture. Then the 500 rule can be a great guide to calculate the minimum exposure time you should use for the individual exposures that will make up your Star Trail image. I have a free guide on Star Trail photography available on my Youtube channel. You might also want to approach focal length a bit different when photographing Star Trails. While going as wide as possible might be the right approach when photographing the Milky Way, now you might want to zoom in a bit to get longer Star Trails – unless you want to capture the stars circling around Polaris.