The process of capturing an image like the one of the container port above.
The camera is pointed out of a moving vehicle and is constantly capturing a single vertical line kinda like these grayscale ones in the diagram, but a lot thinner. As the camera moves, what exactly it sees is changing. If I capture the lines from the camera quickly enough and stitch them together, I can produce a complete-looking image. It’s abitmore complicated than that and getting the results looking good was rather tricky, but that’s the main idea behind it.
Back in the 1990s, digital camera sensor technology hadn’t caught up to the size and effective resolution of medium and large format film, sodigital scanning backswere developed. They capture a high-resolution image without needing a giant grid of pixels by moving a single line of pixels (or three lines for color) across the frame. In the intervening years, image sensors have gotten pretty big (there’s evenone that covers 4×5″ large formatnowadays), but this approach is still cheaper to build for large formats than a giant sensor.
I’d been thinking about building my own digital scanning back for my large format camera for a while, but I’ve never quite gotten around to it because building something to mount properly on my camera seemed too daunting. (Buying onecouldhave been an option, but ones from the 1990s still go for thousands of dollars on ebay and require reconstructing a computing environment of a similar vintage to use.) Late last year, I was watchinga video on Gigawipf’s medium format scanning camera buildand suddenly thought: “what if the entire camera moved and the subject didn’t?” and decided to give it a shot.
Loading film into my large format camera on top of a mountain in Vermont because I’m allergic to doing photography in a normal way. (The resulting pictures from that trip arehere.)
I found some previous photos in the same vein (the Scannoramic project,John Hikerbiker’s experiment,Daniel Lawrence Lu’s reversal of his stationary camera, andMartin Liebscher’s very interesting film shots), but the results seemed like they could be improved upon. Surely taking the speed of motion into account and getting cleaner results wouldn’t be too hard, right?
On the night I thought up this “big scanner” concept, I had to give it a shot. It was a bit late to go out and catch a train, so I scanned my sofa instead.
My comments included lyrics from”Future Me Hates Me” by The Beths, which became something of a self-fulfilling prophecy when I started writing a postprocessor for the next version of the camera loosely based on that code and cursed my decisions.
It looks vaguely like my sofa, but it’s rather squished and the art on the wall is unintelligible. Surely I can do better.
I messed around with the postprocessing and doubled every column, which makes it look less squished, but it’s still a mess because I wasn’t pushing the chair at a particularly consistent speed.
I knew from the start that I’d need to measure the speed somehow, but I was naïvely hoping that I wouldn’t need to measure itthatwell and could simply fudge it. This image, however, shows that even small variations of speed matter. This was my first glimpse into how much of a pain dealing with speed would turn out to be.
For my next trick, I took a ride on the MBTA orange line. I taped my old phone to the seat to use its accelerometer and held my current phone to the window, making sure to turn the frame rate up all the way to 60 fps.