The 500 rule also doesn’t work as well with super high resolution cameras.
First, if you’re using a crop sensor camera, you need to use the full frame equivalent focal length for the calculation, in other words, multiply the focal length by 1.5 before dividing it into 500. RELATED: What's the Difference Between a Full Frame and Crop Sensor Camera?Ī couple of caveats about the 500 rule. For example, if you take a photo with a 20mm lens, the maximum shutter speed you can use without star trails is 25 seconds. Simply divide 500 by the focal length of the lens, and you’ll get the answer in seconds. The 500 Rule serves as a guideline for what the max shutter speed you can use at a given focal length is. Because the stars move in the sky, if you leave the shutter open too long, they’ll smear, and instead of having sharp pin pricks of light, you’ll have weird blurs like you can see in the image below. Shutter speed is a little more complex for astrophotography, and it’s tied to what focal length you use. For professional cameras you can go to 3200 or 6400 in a push, while older cameras will probably need to drop to 800. For most cameras, this will be about 1600.
This means you want to set your aperture to the widest possible value and your ISO to the highest value that gives you clean shots. I live in a pretty light polluted area, but because it’s on the coast, I can take some alright night photos, like the one below that shows the aurora borealis, as long as I point my camera out to sea.įor night sky photography, you’re balancing a couple of things: you want to let as much light into your camera without image quality suffering because of the stars moving or noise. If you can’t get somewhere really dark, the best thing to do is photograph the darkest horizon. You can see in the screenshot below that most of the Eastern half of the US is pretty bad for nigh photography, but the West and Midwest has plenty of options. The best way to find dark skies is with something like Dark Site Finder’s light pollution maps. Professional astrophotographers tend to go far out into the desert or high up into the mountains to get their photos. A city 30 miles away throws off enough light pollution to affect your images. While you can take a photo of the night sky pretty much anywhere, you need to go somewhere dark to get the best results. The vastness of the stars is contrasted with something that’s a lot closer to home. Instead, great photos of the night sky normally feature some landscape as context. An image that’s just of stars looks, at best, like one of NASA’s scientific photos or a computer generated rendering. They make you feel like you’re looking up at an infinite universe. The best photos of the night skies show thousands of tiny stars.