cantilever – Photography, aviation and flight simulation

The Quebec Bridge, the longest cantilever type bridge in the world, celebrated its 100^th anniversary in 2017. For the occasion, several activities were organized in Quebec on September 23^rd 2017, culminating with fireworks near the bridge.

Reflections on the St. Lawrence Seaway. The 100th anniversary of the Quebec Bridge was celebrated with fireworks.

Several workers lost their live while attempting to build the bridge. A Wikipedia article resumes its history: The Quebec Bridge

In 2017, the safety issue was brought back in the news. This time it was about the lack of maintenance that favored an increasing amount of rust on the metallic structure.

The funds that would allow to paint the bridge on a regular basis seems hard to find. The bridge owner, the Canadian National Railway Company, and the different levels of government are attempting to find a solution that would be acceptable for all. This discussion has been going on for years. While the bridge holds on, everything is fine.

September 23rd 2017 celebration for the 100th anniversary of the Quebec Bridge.

About the photography

During the fireworks several boats equipped with an additional lighting system approached the bridge.

It was impossible to get really sharp shots of the boats since they were constantly moving due to the strong current of the St. Lawrence Seaway.

The fireworks lasted about thirty minutes and attracted a huge crowd, both along the St.Lawrence Seaway and on the higher grounds of both Lévis and Quebec City.

Fireworks for the 100th anniversary of the Quebec Bridge

Frequent adjustments of the camera’s aperture and ISO were needed since it is always very demanding for a camera to deal with sudden burst of lights appearing in the darkness. It was necessary to limit the exposure time in order to avoid an accumulation of blurred light trails.

The Quebec Bridge is 100 years old in 2017

The pictures were taken with a Canon 5DSR full frame camera mounted on a tripod. A Canon EF 24-70mm f/2.8L USM was used to capture the fireworks.

A Decision Has to be Taken

You must decide the ideal combination between the following: aperture, speed and ISO. All three are interrelated and choosing one has a direct influence on the other two.

You are facing a beautiful landscape in which you want everything to be in focus: you decide that the aperture is what matters the most. Choosing aperture as the priority is a very popular choice. Let’s consider that you choose F16, which should give you a very interesting depth-of-field but will demand a lot of light. You have to compensate somewhere. If there is not much movement in the scene, and you have access to a tripod, you might decide to choose a slow speed, which allows more time for the light to enter the camera. Doing so, you won’t need to crank the ISO and you will avoid adding useless noise to your picture.

In the picture below, aperture is set at F16. The vegetation in the left corner draws the viewer’s eye toward the pedestrians, and then progressively to the quai des Cageux. We finally see the Quebec bridge, the longest cantilever bridge in the world.

If you decide that speed is a priority, you will have to compromise ISO or aperture. ISO will have to be increased to improve light sensibility, but doing so will increase the size of the grain in the picture. Depth-of-field will have to be adjusted as well since a higher speed does not let much light enter the camera. You won’t be able to pick F16 this time. So you will eventually find that there are some out of focus areas in your picture. With a bit of practice, you can be less demanding on the speed, providing you can follow the subject with your camera (it is like if you were slowing down the subject, so less speed is required).

The picture below was a bit particular: it was taken when I was on a boat rocked by waves. The eagle was far away and was traveling in the opposite direction, thus increasing the relative speed of the subject. The Canon 5D MKII was hand held and 400mm focal was necessary. Speed was crancked at 1/1600 and the ISO required was set at 5000. Naturally, the grain in the picture being larger, slightly diminishes the quality. This was a necessary compromise if the eagle was to be taken in flight.

Eagle observed in the Campbell River region. Summer 2012.

It is getting dark and you want a photo with absolutely no noise and you decide that the aperture is what matters the most. You make no compromise and choose ISO 50. This setting requires a lot of light, because the lower the ISO, the higher the demand for light. In order to make sure that your picture will not be blurred, a tripod will be necessary, since there will be an extended exposition time. In the picture below, the shutter has been opened for ten seconds, with a 9.0 aperture, 200mm focal and 50 ISO. Only the small branches in the foreground are blurred.

IMG_0617 - Resize Queen Mary 2 Québec 2012 watermark eng

Note: in general, it is better to use a tripod as often as possible, even in daylight, in order to optimize quality. Choose a heavy enough tripod to prevent vibrations under windy conditions. A light tripod is easy to carry but does not allow for acceptable pictures in adverse weather. It’s obvious that this Queen Mary II photo would not have been as precise if a light tripod had been used. In this case, it would have meant that continual vibrations would have been recorded during 10 seconds. The boat would have been totally blurred.