We finally got a break in the weather here in the Midwest. At this time of year, we are often treated to days and weeks of overcast skies. Warmer temperatures of 50 degrees Fahrenheit brought an unstable system that got the clouds moving. I could see the clouds moving with my eyes, so I thought this might be a good chance for a timelapse. Although the skies were threatening to rain, I setup my Canon 7D for its first timelapse shoot.

I attached a Canon 24-70mm f/2.8 L lens to the 7D. I set the lens to 24mm, but this is more like 24mm x 1.6 = 38.4mm with the 7D’s cropped sensor. I put the camera on manual, and set the aperture to f/22, shutter to 30, and ISO to 250. With a fully charged battery, I set the intravalometer to trigger pictures every 10 seconds and let the camera run for the duration of the battery. The camera ran for about 90 minutes and took 555 raw images. I converted the images to 16-bit TIFF files and loaded the images into After Effects. I scaled the output to 1024×682 and rendered a movie of the timelapse out at 24 frames per second.

Timelapse of fast moving clouds over NE Indiana from Fourth Order Light on Vimeo.

The rapidly moving clouds made for a challenging exposure situation. I had set the camera ISO and the aperture when the sun was behind the clouds. On a few occasions the sun comes out and blows out the highlights in the sky. On visual inspection of the raw images, I thought the pictures were noisier than that of the Canon 5D Mark II. However once scaled down and compressed for web display, the timelapse looks just as good to me. It would be nice to see more of the sky, but any lens attached to the 7D gets a free 1.6 factor zoom. I’ll have to experiment with aperture priority timelapse on these kind of days since there are sequences where the whites were clipped. However it was a fun experiment and I look forward to creating more timelapse movies with the Canon 7D.