This week I was looking for some resources on the South Carolina Digital Library (www.scmemory.org) when I saw that they have a new collection online. The collection is from the USC library, and is a collection of stereoscopic images of South Carolina.
The images were taken with a twin lens stereographic camera during and just after the Civil War. Most of these are of the Charleston area, and many show the devastation of the war, with ruined buildings seeming to be a favorite topic.
These images were meant to be viewed with a stereograph viewer, similar to the one seen below:
The image card would be placed in the holder, and the off-set images merged into a 3D view in the viewer. When I was growing up we had one of these antiques and a collection of cards, and I loved looking through them.
But what if you don’t have an antique stereoscope? Fortunately, the folks at the have combined the images to form a single anaglyph that can be viewed with current 3D glasses. Anaglyphs are the basis for current 3D technology, and variations are used for the new crop of 3D movies that seem to be all the rage right now.
I’d never heard the term “anaglyph” before visiting the archives. I’m not really a fan of 3D movies, although I’ve seen a couple (Tron, Avatar) and they were impressive. I know that 3D is all the rage, but I also know that there are about a dozen ways to display 3D. The archives didn’t really describe how to view the images, so I had to do some research.
There are a huge number of anaglyphs online, which shouldn’t be so surprising. It looks like the most common type are the cyan-red (CR) variety, where the left eye filters the cyan image and the right eye filters the red. This appears to be what the SC Archives use.
Another popular type, and the type used for some 3D movies such as Coraline are magenta-green (MG) glasses.
Unfortunately, I didn’t have ANY 3D glasses. I was able to find some cheap CR glasses (Hannah Montana specials, no less) on Amazon, so I ordered them. However, I tend to be an instant gratification kind of guy, so want to see if there were any available locally. Best Buy only had VERY expensive glasses for use with 3D televisions. I called our local Blockbuster and hit pay dirt – they had about a dozen left over from some movie promotion, and I was welcome to them. So, at lunch I headed to Greer to pick them up. They turned out to be MG glasses instead for CRs.
I found that they would actually work with CR images if you turned them around and wore the magenta on the right eye and green on the left. The colors were terribly off, but you still got the 3D effect. Fortunately, the images in the SC Archives are all monochrome, so it wasn’t that much of a problem.
This got me thinking about 3D images in general, and what is involved in their creation. Next post I’ll explore how these images are made. Turns out it’s very, very simple to do.