Multi-day time lapse of a solar installation - The final product!

Finally! Here is the final product of the time lapse.

 

You can also watch it on Vimeo. Click this link: https://vimeo.com/62178905

In my previous posts I described the set up and planning for one main camera. In the video, there are two other views from other cameras that were shooting at the same time. One camera was clamped to a pipe and captured the installation of the inverter boxes on the side of the building. It was shooting a time lapse at 1 second intervals. The footage was then sped up in FCP. The third camera was a Canon G12 set on a tripod. It wasn't shooting stills but rather video. I then sped up the footage by 20x, giving it a timelapse effect.

I would like to thank Trina Solar for bringing me on board to do this project. Also, I want to thank all of the staff of the American Lung Association in California for all of their warm generosity. They really rocked! Last but not least, a ton of gratitude goes out to the crew at Everyday Energy. Everyone from their management to the guys working on the roof were super helpful and communicative about what was going on with schedule and logistics. They helped me out throughout the project and were extremely nice the whole time!

Multi-day time lapse of a solar installation - The support rig

Today, I am going to describe the stand and enclosure that used for my time lapse set up. One of the big challenges I faced, was that I needed to mount a camera up high above the roof. The solar array is fairly flat and a high perspective gives the best unobstructed view for the camera. Unfortunately, there was nothing to mount the camera to that got it high enough. After exploring different options like tripods, ladders and light stands, a C-stand proved to be the best solution.

• It could be extended to a height that I needed, 10-15'
• It is heavy duty enough to hold the camera and enclosure
• It could be easily sand bagged 

Next, the camera needed a protective enclosure. The camera was going to stay on the roof for an extended period of time and need protection from rain, bird poop, and other elements. Also, an enclosure on top of a stand wouldn't look as enticing to a thief as a bare camera and lens. 

 

I used a hard plastic case similar to a Pelican case. It was actually kind of tricky to find a case that was the right dimensions to fit the camera into.  I found the Seahorse SE-540 Case at Fuerte Cases. This case was just deep enough to house the 1Ds and 24mm lens with a couple filters stacked on it. It also had enough room to store the AC power inverter and intervalometer next to the camera.

The first step to building the enclosure was to create a window for the camera to shoot through. I cut a square hole that was approx. 6"x6" in the case opposite the lid opening. Then, a piece of 1/4" glass was epoxied into the inside of the opening.

 

 

Next, I drilled holes in the bottom of the case to run a 1/4" 20 screw through for mounting the camera and to run the power cord out the bottom of the case. I drilled a few extra holes in the bottom for ventilation so if the case got hot, it could release the hot air and not become an oven for the camera.

The enclosure was mounted to the C stand with a small ball head.The quick release of the ball head was threaded with 1 1/2" screw that ran through the bottom of the case. The camera mounted onto the 1 1/2" screw.

The stand was raised to its maximum height which was about 13'. Three sand bags weighted down the stand base. While the C stand is fairly heavy duty, the camera still swayed in the wind when everything was fully extended. This required me to tie on some guy lines to the top of the stand right below the camera. By using three lines, spaced equidistantly and tied off with weight bags, the camera could be stabilized in windy conditions. It wasn't perfect, but it did make for a much more solid configuration.

 

In the next post, I'll talk about what worked as planned and what failed and needed improving.

Multi-day time lapse of a solar installation - The camera

This a continuation of my last blog post illustrating my set up and process for a multi-day time lapse of a solar installation. In my first post, I went over the math to calculate how many shots were needed and what the interval duration of those shots needed to be. Today, I'll describe the camera set up that was used and why used what I used.

The Camera
My first thought when choosing a camera was a GoPro camera. It is small, lightweight, waterproof and wide angle. After researching it, I discovered that the Go Pro cameras only allow for a maximum interval duration of 1 second. This project needed between 30 seconds - 2 minutes depending on the full duration of the project. Unfortunately, the Go Pro was out.

Another consideration was power supply for the camera. If it needed to be on for multiple days battery life could be an issue. I didn't want the battery to die and not know it, thus stop capturing images. My Canon 1Ds MKII has an AC adapter that allows it to be plugged in. I'm sure AC adapters are available for a lot of cameras, but I already had one available for my 1Ds so that was a big decider for camera choice. With the AC adapter, the camera could be plugged in and run perpetually for as long it had capacity to record images.

The array was to be about 150'x50', so a wide angle was needed. Originally, I chose a 24mm but changed it to 20mm at the last minute. I didn't know exactly how big the array would be and where the exact positioning of the panels would be, so I played it safe with a wider lens. The resolution of the camera totally allowed for some cropping if the image is too wide.

I'm using a knock off Chinese made intervalometer to control the time lapse. It cost me $20 on E-bay and still works pretty good. Sorry Canon, this is one where I just couldn't justify the $150 price tag for your product.

The weather is predicted to be bright and sunny. Now it's time to go back in time and remember those cool little exposure guides on the inside of Kodak film boxes. It told you that in order to expose the 100 ISO film properly on a bright and sunny day, the exposure needed to be set at 1/125 sec at f/16. Based on my intervalmeter's limitations, the fastest shutter speed I can use is 1 second. 1 second is 7 stops brighter than 1/125 sec. For a 1 second shutter speed, that would require an aperture of f/180. Most lenses have a minimum aperture of f/22 or f/32 so it is necessary to cut down the amount of light entering the lens.

This requires a neutral density filter. which is a neutral grey filter that simply cuts down the amount of light entering the camera. For this project, I used an ND 8 which cuts the light by approx 3 stops. I also stacked a polarizing filter on top of the ND to further reduce the light by 1 1/2 stops. The polarizing filter also enhanced the saturation of the colors and reduced the glare on the reflective solar panels.

The the final exposure will be f/22 at 1/2 sec. Even this will be a little over exposed but the RAW files can be pulled down in Lightroom to achieve a good exposure.

My next post will describe the housing that protects the camera from the elements while it sits on the roof for a few days.