Planning a sunset


We intend to travel to the Canadian Rockies and have a photo in mind in the Assiniboine massif area with some mountains in the background and we want to know if the sun will light it up at the last minute to make it look red. In the background we would have the lakes and in the foreground, the descent from the hill that we are going to take the photo.

We choose an starting date of February 15th from the most photogenic and photographed area. Then we’ll search the best place and the best dates for capture the perfect shot.


We search for Mt Assiniboine or Mount Assiniboine in the search box by name (Ctrl + F). We type the place name and then hit enter key and wait for the inputs to come out. The view will be centered over the mountain, from an overhead view with the black pin (our position) in the center.

Ok. So here we are at the top of the mountain, but this is the main sibject of the photo, not the actual position of the camera.

The first thing we will do is change the view, clicking on the top button of the group that we have on the right or with the keyboard combination Ctrl + D. We are already in the 3D View and we can rotate and change the altitude of the camera, which will be very practical when planning our photo. To change the perspective of the camera, press the right mouse button, and while we have pressed, move the mouse. To get closer or further away, we’ll use the wheel.

Let’s place the black pin more or less on the slope that we see in the image, making a long press on the desired point (Ctrl+ mouse click is also valid). The black pin will change places and the color lines will be displayed for that new position.

Assiniboine circled and the camera position below.

Since we want to work only with the sun, we will hide the moon lines and the GC with the Ctrl + 1 key combination (or Ctrl + Shift + Alt + 1, to show only the sun lines and sun events in the right panel).

Working only with the sun. The view now seems cleaner without all the lines.

Then we’ll pick the date. Click on the top of the assistant where you indicate the date and we will navigate the calendar until February 15th. Click twice.

The calendar. All interesting photographic events are shown.

Let’s placing the purple pin. We will place the landmark pin on top of Mt. Assiniboine. To do this we use the Alt keyboard and mouse combination + mouse click just on the peak. If we have not placed it correctly, we repeat until we are satisfied with the position.

Black pin on the hill side. Purple pin placed on top of Mt Assiniboine.

If we look closely, between the two pins we can see a solid black line and another one that runs through the entire surface as if it were the shadow of the previous one, which is discontinuous (pointed with an arrow). If at any time, the discontinuous one was above the solid one, it would indicate that there would be an obstacle in that place that would prevent the view between the camera position and the landmark. In this case, we will have visibility between the two points.

Next, we’ll activate the sun lines over the landmark to see if at dawn the chosen summit will be illuminated or not. The button to activate it is on the left, with the purple pin image with lines below.

By default, the sun lines will be activated on the purple pin (sun imagebelow the marked image); if we wanted the moon’s for example, we’d change with the bottom button.

Camera or photographer lines and landmark lines are marked in yellow.

Lines above the landmark will not be seen if the sun is not visible in the sky. If we change the slider in the light bar, both the lines on the black pin and the purple pin will rotate, both in parallel.

Finally we have to take the light bar at sunrise time. In the event panel we see that the sunrise occurs at 07:54.

To carry the light bar or time we can slide it until that moment, by clicking on the time or double-clicking on the sunrise row. The time will be set to 07:59 and we will see how the light lines on the pins have changed.

Let’s take a look what information the 3D View assistant is showing us.

First, we notice that the colors of the lines have changed to red, indicating that the light is sunrise (the light of the setting is also of the same color).

Next, we analyze the behavior of the light lines on the ground.

As we are interested in the selected summit with the landmark pin we follow the origin of the light that we want to have an on top. At dawn the light comes from the east and following that line, we realize that the first light at the top of Mt Assiniboine is hampered it by a far mountain. If you still don’t see it clear, the solid line disappears inside the mountain and the dashed line passes over, clear obstacle indicator. Look at the area marked in the image.

At this distance from Mt Assiniboine it seems that there’s no obstacle
Almost an obstacle in the yellow circle.
Circled in red the obstacle that prevents the first light.
Even at 07:58, 4 minutes after the sunrise, sunlight is blocked.
One minute later (07:59), sunlight vision is clear. But, maybe it’s too late to get the reddish light on the peak.

It is clear that at sunrise, our summit will not be directly illuminated, but we can know, since we will be there, when it will light up. We should check other near dates if our landmark will be illuminated at sunrise, now we know how to preview that.