This idea kind of popped into my head fully formed one morning while I was loading my dive gear. I only needed a few minutes to build the hardware, and the shoreline of the dive site would be a lovely subject of the experiment.
Every digital camera nowadays has a feature to help you stitch overlapping photographs into panoramas I thought why not use multiple cameras and do the same thing with video. There’s nothing earth shattering about this idea it’s essentially the same thing that Google does to create street view and do a lot better job of it than I have (but they spend a lot more money on it)
What I’ve got here is a 10 inch long piece of strap aluminum with a quarter-inch hole drilled in either end and a tapped 1/4 20 hole in the middle. This allows me to mount two cameras on the tripod and point them together as a unit. These are a matched pair of Canon powershot A430s that I got on eBay for cheap. The cameras are secured with homemade thumb bolts that originally made for my fig rig.
There are few details about this that beg further discussion. The two videos were stitched together in Adobe Premiere Pro, I’m not going to go into how to use premiere Pro, if you know how, this task is fairly straightforward and learning premiere Pro is beyond the scope of this discussion. This can of course be accomplished with whatever nonlinear video editing system you prefer.
The first step is temporal synchronization of the two video clips. Right after I started the cameras I clapped my hands behind them impressing the sound on both audio tracks. You simply play through the clip and identify the frame during which the handclap occurs setting a numbered marker at that frame. The marker follows the clip through its journey from that point on. Once both clips are on the timeline you simply align the two markers.
You’ll notice that misalignment of the two video frames is visible at points one and four, this could’ve been eliminated by masking a few pixels across top and bottom.
The A430 is nearly decade-old technology and was a low-cost camera from its inception as a result it has trouble with some more demanding photographic situations. The left camera was getting a little too much sunlight in the lens which it tolerates poorly. I needed to make significant adjustments to the color of the left frame to make it blend with the right frame, even so the seam is still visible and the left frame is noticeably lower quality than the right frame. Also the camera only shoots video at 10 frames per second which kinda shows up once you’ve blown it up and rendered it at 720p high definition like I did.
To align the two frames I put the right frame on top and set it’s opacity to 50%, and used the rock at point 3 as a fiduciary mark, moving around the right frame until the two rocks blended into one. Due to lens distortion (which I did not attempt to correct) there is increasing misalignment the further from that rock you get. This is apparent at point 2 right next to widely known local landmark, Cape Forchu lighthouse(Barely visible). At point 5 another local landmark, bug light can be seen. There’s also misalignment visible in the rocks at point 4.
When I have occasion to do this again I’ll be sure to get a shot of a high contrast object in the center of the combined frame to provide a good marker for alignment.
More work in postproduction and more care in shooting could have eliminated most of these artifacts however perfection was not really the point of the experiment and in my opinion the artifacts add interest to a composition which is otherwise very boring. I actually recorded 26 min. of this, during that time the passing of the seagull was the only break in the monotony.
I never did get that dive in, although it doesn’t look it in the video (I left out the audio of wind whistling in two microphones) the weather was actually terrible for diving.