When the sky turns blue, photographers come out to play
The “blue hour” is one of the most interesting and emotive times of day to capture photos. I’ve taken many of my favorite pictures at blue hour – actually, even more than I’ve taken at sunrise or sunset. But what is blue hour, and how can you make the most of it? I’ll go through some of my top tips and recommendations below.
Blue hour is simply the time of day before sunrise and after sunset when the atmosphere has a deep, dark blue color.
Like the famous “golden hour,” blue hour is not really an hour . Its exact length depends on your latitude, time of year, and weather conditions. The important thing is that the sun must be a decent way beneath the horizon, and the sky can’t have too many sunrise or sunset colors – mainly just blue.
Blue hour actually lasts much longer than many people think. In my experience, on a clear day, blue hour includes at least civil and nautical twilight – and the tail ends of astronomical twilight as well. This means you can easily capture stars during the edges of blue hour, giving the Milky Way a bluish appearance:
Despite its usual dusty brown color:
Why Take Photos During Blue Hour?
There are plenty of reasons why blue hour is such an excellent time of day for photography.
First, not as many people take photos at blue hour compared to sunrise and sunset. This gives you the chance to capture unique, compelling images and photograph popular locations with minimal or zero crowds.
Second, blue hour is a great way to convey certain emotions in your photos that may otherwise be tricky to capture. Images from blue hour are generally dark and high in contrast. The color blue also carries its own range of emotions: serenity, sadness, peace, and so on. These emotions do not work for every photo, but if your scene demands darkness and blue tones, it’s hard to beat this time of day.
Third, along the same lines, blue hour simplifies your photos. Unlike sunrise and sunset, which usually have a wide range of colors for you to capture, images taken at blue hour are more monotonal. Even colorful subjects like green trees and red rock formations take on a blue hue at the right times of day. Personally, I am a big proponent of simplifying your photo’s emotional message for the best possible results – and the unifying power of blue hour is a great way to accomplish this for yourself.
Fourth, there is one important situation when portions of your photo do not turn blue during the blue hour: when the image has other sources of light. This is especially true with artificial light from high-pressure sodium bulbs or other warm color temperature lights. Quite simply, your photo in cases like this (largely cityscape photography) can have a beautiful orange/blue color contrast that gives the image some punch. However, you’ll need to time this pretty carefully; there is usually only a brief window when the sky and the city lights are about the same brightness, making for the most even exposure between them.
Those are just a few reasons why blue hour photography can be so interesting. Below, I’ll list my preferred camera settings for blue hour photography, so you can avoid making technical errors and harming your photo’s image quality.
Recommended Camera Settings for Blue Hour Photography
Despite all the benefits of taking pictures during the blue hour, you need to be careful with your camera settings when you do. When a large portion of your image is the same color – in this case, blue – it can be difficult to find the right exposure that doesn’t blow out any details. On top of that, the lack of light during blue hour may necessitate more extreme camera settings than you’d otherwise use.
First, use a tripod – something I consider essential for most sunrise and sunset photography, let alone even darker conditions like the blue hour. If you don’t use a tripod for blue hour photography
Beyond that, a critical step is to focus properly. Often, blue hour will be so dark that your autofocus system won’t work properly. If this is the case, try to find a bright object for your camera can lock onto, like a well-lit building or the moon. If you are focusing on something closer, the easiest solution may just be to shine a flashlight on your subject. And, if all else fails, manual focus is the way to go. (Even if you focus automatically, you may want to magnify your photo in live view to verify that the camera focused well.)
After focusing, the first setting you should work with is aperture. Pick an aperture that results in the optimal depth of field for your intended shot, with the sharpest possible photo overall. Our introduction to f-stop will help if you are unsure.
Next, set your ISO to its base value, generally ISO 100. Your goal is to capture as much light as possible via shutter speed and aperture rather than brightening your photo with ISO. You’ll get better image quality that way.
Finally, you’ll need to select a shutter speed that gives you the right exposure. Start by following your camera’s meter and then looking at your histogram to see if anything in the image is overexposed. Don’t just look at the overall histogram, but also the separate histograms for each color channel; blowing out one color channel is almost as bad as blowing out all three.
Because blue hour involves some pretty dark environments, it is possible that you will max out your camera’s shutter speed to 30 seconds, or whatever your camera’s limit may be. In that case, use a remote shutter release in combination with your camera’s Bulb Mode to take extra-long exposures. Or, if you are taking pictures of the stars during blue hour, check here for our recommended Milky Way photography settings.
Lastly, a note about exposure: It is easy to end up with dark silhouettes in your blue hour photos. In cases like that, you may be tempted to use a longer exposure that slightly blows out highlight details in exchange for brighter shadow regions. But that’s usually a mistake. Instead, it is much easier to recover near-black shadows than overexposed highlights in post-processing (of course, assuming you are shooting raw). In really tricky conditions, you can always bracket a series of photos and create an HDR to get more highlight and shadow detail. But whatever you do, make sure to get at least one photo of the scene where zero important highlights are blown out.