When I was a kid, my uncle had a little device called a “View-Master” (which you can read about here) and a bunch of “reels” for it showing photographs of U.S. National Parks. The twist is that the View-Master showed you 3D, full color photographs – reasonably detailed and quite sharp. I was fascinated by the thing; that 3D effect was entrancing. I had no idea how it worked, though I could see that there were actually two photos of each scene on the “reels”, one for each of my eyes.
The phenomenon exploited by the View-Master is the same one that lets us see the real world in 3D: the fact that our two eyes are a short distance apart and see slightly different perspectives on the same scene. Our brains process that information and turn it into the vivid 3D world. View-Master uses photographs taken by two cameras spaced apart horizontally (like our eyes), and then presents them to our eyes to trick our brain into seeing essentially the same 3D image we'd see if we were actually there, where the camera was.
For years I've played with stereo photographs without any special equipment or software, either to take them or to view them. For example, the photos below I took yesterday with a hand-held camera. First I took the photo on the right (which is actually for your left eye); then I moved the camera about four inches to the right and took the photo on the left (which is actually for your right eye). Nothing tricky about this, other than I held the camera as close to the same height as I could, and was careful to point it at the same object for each photo:
Here's the part that may seem a little magical to you if you've never actually done it: you don't need a View-Master (or any other stereoscope) to see these images as a 3D image. You just need to be able to cross your eyes. Seriously. This web site has a great description of how to do it (right where it says – wait for it – “How To Do I”. Just as the author says, once you get started with it, it's remarkably easy to do. I've been doing this for 30 years or so, after accidentally discovering the technique myself (I didn't read about it until many years later).
If you use my image pair above, you should see some little pillars formed by something rain-resistant (like a pebble) so that falling rain erodes everything around it, but not the pillar holding up the rain-resistant item. These rain pillars are very common around here because our rain normally falls straight down – we generally don't have wind and rain at the same time. These pillars should be vividly 3D if you do it right. The sticks above the mud will also be vividly 3D. Can you do it?
This 3D imaging is something I'd like to putz around with, now that I have some time to do it...
Monday, January 14, 2013
We just got back from a followup with Debbie's surgeon – and she now has permission to start putting weight on her (formerly) broken knee. This is a huge milestone for her! She's ramping up slowly, from 15 lbs today to her full weight in three weeks. Woo hoo!
A parable, via reader Jim M., with a nice twist:
A tourist walked into a Chinese curio shop in San Francisco . While looking around at the exotic merchandise, he noticed a very lifelike, life-sized, bronze statue of a rat. It had no price tag, but was so incredibly striking the tourist decided he must have it. He took it to the old shop owner and asked, "How much for the bronze rat ?"
"Ahhh, you have chosen wisely! It is $12 for the rat and $100 for the story," said the wise old Chinaman.
The tourist quickly pulled out twelve dollars. "I'll just take the rat, you can keep the story".
As he walked down the street carrying his bronze rat, the tourist noticed that a few real rats had crawled out of the alleys and sewers and had begun following him down the street. This was a bit disconcerting so he began walking faster.
A couple blocks later he looked behind him and saw to his horror the herd of rats behind him had grown to hundreds, and they began squealing.
Sweating now, the tourist began to trot toward San Francisco Bay .
Again, after a couple blocks, he looked around only to discover that the rats now numbered in the MILLIONS, and were squealing and coming toward him faster and faster.
Terrified, he ran to the edge of the Bay and threw the bronze rat as far as he could into the Bay.
Amazingly, the millions of rats all jumped into the Bay after the bronze rat and were all drowned.
The man walked back to the curio shop in Chinatown .
"Ahhh," said the owner, "You come back for story?"
"No sir," said the man, "I came back to see if you have a bronze Democrat."