Does anyone know of an easy way to draw a binary Fresnel zone plate such as the one shown here?
In this case the size of the innermost circle is immaterial but each successive ring (black or white) must be of equal area to the previous one.
I am searching for a quick way that does not involve too many complicated calculations.
Basically, the ratios of W values are just the square roots of the natural numbers, 1>2>3>4 etc.
Square root of 1 = 1
Square root of 2 = 1.41421
Square root of 3 = 1.73205
Square root of 4 = 2
If you start somewhere in the row, you will have to use quotients by dividing the latest number by the first one (it is 1 when you start with the 1). So it is much easier to start with 1 and then just delete the innermost one(s) if desired.
So almost any small calculator can do it for you. You may save the innermost width in the memory and multiply that by the square roots as you go, or you may use copies of the first circle and just multiply the W/H by the square roots as you go.
Great! May I ask what it's application is/what you're using it for?
You've given ideas. Recently became obsessed Shepard Fairey's work and this technique is a nifty way to create some interesting elements/pattern fills, kinda like he does.
Oh, is that what we're called? Sweet. Greetings, fellow werewolf. Crap of mine.
Looking through Fairey's stuff, look how he uses layered patterns to create interesting "dither" textures with just one color print; very cool.