The blue hour comes from a French expression, l’heure bleue, which refers to the period of twilight each morning and evening where there is neither full daylight nor complete darkness. The time is considered special because of the quality of the light at this time of day.
When is blue hour?
Blue hour happens twice a day, just before sunrise and just after sunset. The light during the blue hour is extremely fleeting, so you need to be ready to shoot. It only lasts between 20 to 40 minutes, depending on the weather, and your geographical location. During this time, the sky can turn brilliant shades of blue and reflect orange, yellow, purple and pink.
What to capture during the blue hour?
Being that I'm an architectural photographer of course I will say capturing cityscapes and architectural exteriors is the best. Landscapes are always good, but I really love blue hour photography for architecture. Since shooting during the blue hour requires a long exposure, car light trails will be captured in the image. If it is partially cloudy then the movements of the clouds can be used to create a drag effect. When capturing tropical beaches the movement of water appears to be wispy or dreamlike. All of these effects add to the dynamics of the photograph.
5 easy tips for blue hour photography
Blue hour photography is easy, the hardest part might be getting there before it’s over.
Use a Tripod
With these long exposures you won’t be able to get sharp images by handholding your camera.
Use a remote or self-timed shutter release
This is necessary when triggering the shutter to avoid any kind of movement in your camera
Set your ISO to 100 to begin with
As it gets darker during an evening blue hour session, you may have to bump up your ISO to keep your exposure to 30 seconds or below.
Include artificial lights
Your blue hour photography will be easier if you choose a location near electric lights. This extra light may also add drama and interest to your photos.
Use a small aperture, f16 or f22 if you want to get good starbursts from streetlights
If I want good starbursts, I usually start with f16 and ISO 100 if possible.
It’s a good idea to plan ahead for blue hour photography since this time frame is relatively short. Knowing when sunrise or sunset is will give you time to get to your location and set up for when the blue hour arrives. It’s also important to note that the sky will appear blue to your camera before it looks blue to you. So don’t be afraid to try some test shots just after sunset, to check for the blue tint.