Sunrise is defined when the sun starts to appear over the horizon. On the right side of the chart below; the horizon is considered to be at an angle of 0°. The official time of sunrise is when the sun breaches the horizon at 0°.
But in Banff and any area where the horizon is obscured by mountains, it is useful to have a broader definition of what sunrise is in order for it to be meaningful to the photographer.
For me, knowing when the sun is on the horizon doesn’t necessarily give me an idea of what type of light to expect because of the mountains blocking the horizon. What I want to know most are these three things:
Will the sun light up the mountains?
If the sun will light up the mountains, at what time?
When will the sun give me some wonderfully pink clouds?
To answer these three questions, we need to dive in a bit further into the direction and different qualities of sunlight in the morning.
If you are looking to photograph a grand landscape where the sunrise is directly hitting the mountain tops you need to consider which direction the light will be coming from in relation to what direction you are photographing. To preplan and know what direction the sun will be rising in regards to the direction you are photographing, I use the apps Google Earth and PhotoPills.
Through my experience of photographing sunrises in Banff National Park over the years and in different seasons, I have found that the sun generally will first strike front lit mountains fairly close to official sunrise times as published by the PhotoPills app when using an exact GPS location. But as in the example used in this article of Moraine Lake, you will see a discrepancy of a few minutes earlier. It has varied by up to 10 minutes at different locations and time of year. This is most likely due to the height and relative distances of other mountains blocking the sun. So to be sure, it is always wise to show up much earlier.
For Moraine Lake and Banff National Park, depending on how high the clouds are in the atmosphere, you should expect the clouds to start reflecting the suns light about 20 minutes before official sunrise. This time is often referred to as golden hour. Golden hour is a theoretical time span of about an hour that starts during civil twilight at about -4° and extends to about 6° past official sunrise as shown in the sunrise diagram above. Photopills gives out the theoretical golden hour times.
You can read the full article at rmphotoadventures.com.