In order to help get you ready to venture out over the coming months, I will briefly go over a few considerations to help you plan and execute a successful night out. Lack of sleep you’ll have to deal with on your own 🙂
I’ve head it said that the best camera is the one you have in your hand at the moment. And it’s true. Regardless of what you have you should get out and try your hand at night sky photography. You may have some limitations at first, but you will always gain from experience. Later you can focus on what best equipment to have to make the most of future outings. All that said, I do have a few recommendations for you.
Milky Way season and night sky photography is all about the sky, right? Accordingly, you want to use a wide-angle lens, 24mm or wider (based on full frame). This will allow you to get a greater amount of sky in your composition. Moreover, your lens should be fast. What I mean is it should be capable of an aperture of 2.8 or wider. This is important when trying to capture stars as points of light without getting star trailing. New lenses are coming out all the time. When considering one, do some research on their performance for night sky photography.
Cameras and camera sensors have come a long way. While I believe a full frame camera is best suited for landscapes in general because of the sensor size, APS-C cameras can work just fine for Milky Way photography, especially when using lenses as mentioned above.
Make sure you have a good steady tripod. Your exposure times can be up to 30 seconds, or longer. A slight breeze or settling in soft ground can interject movement blur and ruin your shot. So make sure you invest in a strong tripod capable of supporting the weight of your gear. While carbon fiber tripods offer strength and the advantage of lighter weight, aluminum tripods can do fine for those needing to be more budget minded. Just be sure to get a good sturdy one. Manfrotto is one manufacturer that has some good options but there are others as well.
In a pinch you can get by with a poor man’s cable release, i.e., 2 second timer on your camera. However, I would highly recommend getting a dedicated cable release. In fact, I would suggest an intervalometer. An intervalometer will allow you the most control, allowing you to set the exposure time, a set interval between exposures, and a specific number of exposures. These devices are invaluable and increase your options to shoot star trails or compile time lapse sequences.
Focusing at Night
Focusing at night is one of the biggest challenges. There are a few techniques to simplify this. When doing Milky Way photography, you want to focus on the stars, which would essentially mean focusing on infinity. But all lenses are different, and you cannot simply adjust your focus ring until it shows the infinity mark. You can focus on some distant object, such as the horizon before dark, and then carefully tape down your focus ring so as to not accidentally move it later. Also, you must then turn off your auto focus.
One of my favorite ways to focus at night is using live view. I will magnify to 10x and focus on a bright star slowly moving the focus ring back and forth until I can see the star at a fine point of light.
There are times when you may have to refocus. Another way to quickly return to your infinity focus point is by marking tape on your lens in a fashion shown in the images below. This can save a lot of time and frustration in the dark.
One issue I notice when working with students in the field is a tendency to under expose Milky Way shots. This happens because of a couple of reasons. First, the photographer is using too low an ISO setting in hopes to avoid noise. Second, the decision to use lower ISO seems to be reinforced when they view an image on the camera’s LCD in the dark. Remember, your eyes will have adjusted to the darkness, and you are looking at a bright image displayed on your LCD.
In most cases about 1 1/2 hours after sunset you should be using an ISO setting of between 3200 and 6400.
Look at your histogram. A correct exposure should look something like the image to the right. If your histogram is more all jammed up to the left, you are likely under exposed and you will need to adjust your histogram accordingly. Remember…Always trust your histogram!
Having touched on the ISO settings, we need to think of how long our exposures should be. Here we can use what is referred to as the “500 Rule”. This guide will help us maintain the stars as points of light and avoid unwanted slight star trailing. It simply works like this: Divide 5oo by the focal length of your lens and the result will give you the maximum exposure time. For example…500/24mm = 20.8, or roughly 21 seconds. This of course is based on a full-frame cropped sensor. If you have a APS-C sensor, you’ll have to make the adjustment. The table shown here will make things easy for you.
500/lens focal length = max exposure time for stars as points of light
When to shoot the Milky Way
Early in the Milky Way season the Milky Way core rises above the horizon just a couple of hours before sunrise. As the Spring and Summer progress the core rises earlier until it is visible soon after sunset. Remember the darkest part of the night, usually about 1 1/2 hours after sundown or before sunrise, is the best time to shoot the Milky Way. A great aid to planning is an app such as PhotoPills which is available for both iPhone and Android. Other apps are also useful.
The time is upon us. Get out and have some fun!!!
I will be hosting several Milky Way season workshops this summer in the Flint Hills area of Kansas. Please check out the details below.