Photographer Robert Shimmin has revived a 150-year old photographic tradition known as "tintype" in which photos are printed directly on a lacquered sheet of iron. The image you see is technically a negative; the dark parts are the metal showing through, while the light parts are formed by the emulsion.
Tintype initially got popular because it was a one-step process -- the negative is the print -- and that allowed photographers to pump out the images quickly. They were popular in public settings like amusement parks, where mobile photographers could snap your image and hand it to you after a few minutes.
But if you want to get a feel for why tintype is would be interesting as an artform, I think Shimmin nails it. There's something about our proximity to this technology that makes it more interesting than film or digital photography.
"Even shooting a modern subject, it almost looks like it's from another time period that you can't quite pin down," Shimmin says. "So you're looking at something that's of today but not necessarily of today."
In other words, using the older technique unmoors the image from the progression of photographic technology. The tintypes Shimmin makes could have been produced any time in the last 150 years. While normally it is the newest technology that blows us away -- the Lytro, say -- using the oldest tech can be sublime, too. And when you're talking about tintype in an HD video posted to Vimeo and linked via Twitter, your images suddenly say that you're not just up with recent times, you're up with all times.