[Gabriel Lebec]

Hi everyone.

A while back, when I got my first high-quality blade, I wrote in response to someone's questions:

Of course, everything depends on the lighting and angles... That's one of the most attractive aspects of nihonto, for me - not just the intrinsic effects and properties of the sword, but the way those effects change dramatically with the light. It makes the surface alive, as one gets the feeling that they are looking *into* the sword, that it has visible depth. If you want to be scientific about it, I would venture that the brain produces depth perception by comparing differences between the information from each eye; since in the case of nihonto, the visual aspects of a blade can change so dramatically with just a slight change in angle or perspective, it is my understanding that the brain becomes confused when trying to combine the images and can produce the illusion of depth in some areas (especially the ji, if there are noticeable reflections). Hmm... maybe I should make a tiny little mpg video of moving the blade around, showing how the colors change? What a tempting idea...

Well, I haven't yet made an mpg, but recently I've been experimenting with stereoscopic imagery - simulating the effect of 3D by forcing the brain to combine two static images into a single image.

The trick works like this: as I mentioned, the human brain produced depth perception, interprets texture, determines luster, and enhances detail by comparing the different data from the left and right eyes. That difference in data is the result of light entering each eye from a slightly different angle.

Therefore, if you take two photos of a scene, each from a different angle, and the difference between points of view is the same as the difference in angle and distance between human eyes - (about 6.5 cm and whatever angle is determined by the subject being examined) - then you have simulated the two different images that the brain would normally combine if it was staring at the scene in person.

Then, to make the brain combine the two images into one, another trick is necessary. Gimmicks and physical devices (such as special viewing boxes) aside, the viewer must force each individual eye to look at each individual photo - no mean trick, especially without practice.

There are two variations of this method. One was made well known through the delightful (or infuriating, depending on your experience) "Magic Eye" series. In those images, computers were made to produce the necessary patterning instead of photos - so that the 3D image became "hidden" in a complex background, and only the proper technique would reveal it. This technique was the parallel technique. Basically, the viewer would learn to relax each eye so that instead of focusing on the paper in front of him, he would be focusing on two separate parts of the paper - and the brain would suddenly recombine those two separate parts into a single 3D image.

However, the parallel technique only works when the distance between overlaid images is small - so it does not work for photos, for which the entire width of the image must be overcome by the eye in order to produce the illusion. [Edit: actually, a skilled or practiced viewer can control his vision well enough to view large photos with the parallel technique; however, it is more difficult to learn to do than the next technique I describe...]

So I've tried the other method; the "cross-eyed" method, where instead of relaxing each eye, the viewer must slightly (SLIGHTLY) cross his eyes, forcing each one to see the image on the other side of the page.

This method unfortunately produced more strain on the eyes, so it is not recommended to be used over long periods of time with many images. However, it works on larger photos, and is easier to learn than the parallel technique.

For visual aids and more info to accompany this admittedly confusing explanation, try these sites: http://www.lightwave.soton.ac.uk/experiments/...ision.html
http://www.techmind.org/stereo/sintro.html
http://www.colorstereo.com/texts_.txt/aboutstr.htm

Here is a good explanation of how to view autostereograms with the cross-eye method:

http://www.vision3d.com/methd04.html

Please read it and practice to learn the technique. I promise it'll pay off in a second .

And also, a word of encouragement to those who are unfamiliar or frustrated with the technique, from one of those websites:

[Scott H.]

Well, that is very cool. I just got back from a trip to NY and got to see my first authentic nihonto pieces. I was awestruck to make an understatement. They looked like they had just been made even though over seven hundred years old! And you're right, they DO seem alive!
Your images are great! Thanks for sharing!

Enjoy in long health,
Scott

[Gabriel Lebec]

Thanks Scott.

Might I assume you went to the Met? The Metropolitan Museum of Art is where I see the most high quality nihonto, as it is relatively close by and has an excellent collection.

Yes, it's a wonder what careful preservation and top-noch togi (polishing) does for nihonto; the examples put on display by the Met, for instance, often look as if they had just been made. It's quite sad to me that older western medieval and renaissance weapons rarely (as far as I can tell) share the same level of preservation, as the few excellent antique western swords I have seen that *were* in good condition were also quite breathtaking.

Good to know that you had a good time while in NY, and also that you like the images.

[Scott H.]

Gabriel-
Yes, it was the Met that I visited. Sadly, I only had a few minutes to peruse the museum, but it was well worth the admission. And, as you said, it's too bad that the western sword/weapons typically did not receive the same care as the eastern through the years. When you compare a katana of c. 1350 with a long sword of the same period the long sword will inevitably be pitted and dull and have any number of problems with the grip. Yet the katana looks like someone just presented it to its first owner. At least that's what I've found.
Thanks again for sharing!
Scott