Approaching Storm

This evening I chanced to look out the kitchen window to see the approach of rather dramatic-looking thunderheads. We were in a "Severe Thunderstorm Advisory" according to the local TV Weather Channel, so I took the opportunity to grab my ol' trusty Canon 40D, plug in a Canon intervalometer, and set it up on a tripod in my backyard to face the oncoming storm.

Passing Clouds from David Rilstone on Vimeo.

The lens used was a Canon 17-40mm f/4.0 L lens. Setting the focus to "manual", it was easy to hand-adjust by using the liveview feature with its multiplier of x5 and x10. I selected Aperture Priority @ f/4 and a relatively high ISO of 400 to give me reasonably quick shutter times in view of the coming sunset. The first sequence I chose an interval of 15 seconds, the second sequence had an interval of 5 seconds. (Next time I'll opt for an interval of one second - more on this later).

I've found I get the best results shooting these sequences using "Small .jpg" and "Landscape" picture style. The small .jpg's are already close to 1920 x 1080, which is what I wanted the final video resolution to be. I then imported this series of photos from the CF card to my hard drive using Lightroom 2.7. Upon quickly examining the photos for any obvious rejects, I then exported them to a separate folder -- Lightroom has the phenomenal ability to rename each photo in turn by sequence number ie. ".001" and upwards -- this makes it easy for your NLE (non-linear editing) program to import each photo in correct order to produce a timelapse film.

In this case, I used Adobe Premiere Pro CS5. When rendering this video clip to 24 frames per second, I found that the cloud action was much too fast, hence I reduced the overall speed to 75% -- which is an improvement but looks slightly choppy. As mentioned above, next time I will take photos at one second intervals to give me a slower, smoother cloud action.

For this timelapse, I dusted off the 40D since my 5D Mark 2 and 7D have been heavily pressed into video service of late. Timelapse sequences are a great use for the older camera models (ie. 20D, 30D) since these cameras accept the same intervalometer as the more recent 50D, 7D, and 5D Mark 2 and will likewise give fantastic resolution in the end result.

The music is "The Chase" by Kevin MacLeod.