Monday, October 26, 2009

Dazzle camouflage

I was riding with Alistair this weekend and he was wearing his '08 Team Specialized Jersey. The jersey is bright red with a large white S cutting across the front and back (see picture). When you look at it really stands out. Yet when racing in a pack I -and many others- had always noticed how hard it was to find him, or his team mates in the group.

Then I was reminded of something I read a long time ago about camouflage. There is such a thing as "very visible" camouflage, technically called Dazzle Camouflage or Razzle-Dazzle.

It sounds counterintuitive but when you paint an object in bright and large patterns it plays tricks on your visual system, especially when the object is moving.

Dazzle camouflage was used briefly in WWI to confuse enemy gunners. It was said to interfere with the gunsights that were used at the time. But I can attest to the fact that you don't need a gunsight to be confused. What matters here is the contrast, the size of the patterns, and the speed of movement. When these three interact within certain ranges, things can become very difficult indeed.

Here is a picture of a British warship painted in Dazzle. The British abandoned this type of masking when radar was introduced. Painting dazzle is more expensive and time consuming than "regular" camouflage.
What happens in dazzle is that your visual system wants to break up the image along the very visible edges and then your brain puts pieces together that don't belong together. I.e. it is as if you parse a piece of text the wrong way and make words out of groups of letters that don't belong together. That makes all subsequent recognition next to impossible. The trajectory, the speed, even the boundaries of the object all become hard to find, let alone the actual recognition of a person.

The newer Specialized Team jerseys have a smaller S pattern and less contrast making for a much improved experience.

On Saturday I went to Hellyer and did a three hour track workout. I am still trying to get used to the fixed gear. Things work well as long as speeds are reasonable. But I do not like going all out on a fixed gear.

I rode a 200 m time trial with flying start and got to 15 s -which is pretty slow-. I know I was holding back for fear of locking up once past the finish. Apparently my intentions were obvious because one of the guys came over afterwards and told me, you didn't look like you were going all out on that bike? Well so much for that.

I wish we had a track in Oakland or Berkeley so I would not have to waste so much gas just to get a workout. Driving to a workout is not something I like doing.

On Sunday, I rode with Alistair and Barbara up Redwood to Chabot park. I tuned up KOM some more beforehand and we are getting close to perfect. Some minor glitches (the saddle squeaks a bit) remain to be worked out but the bike is almost perfect now. It is a great ride.

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