The effect of the Iterations Parameter

Pixels in the images are coloured according to how many iterations, i, are required before the magnitude of Zi, the value of the ith iteration, becomes greater than 2 (|Zi| > 2). If we reach the maximum iteration count and Z hasn't diverged we colour the cell black. When Z does diverge we count the number of iterations at the point when |Z| becomes greater than 2 to choose a colour.

If you try generating your own patterns you will find that the further you zoom in the larger iteration cut-off you will need to draw decent patterns.

The following two images illustrate the effect of changing the maximum number of iterations from 16 to 2400. In this case 2400 is probably too many, but 16 clearly isn't enough. If you choose too many the image will take ages to draw but otherwise will be ok.

Example
Example
16 iterations 2400 iterations

These pictures also illustrate the advantage of the new colouring algorithm. The locations of the colour bands no longer change depending on the number of iterations, so if you want to create a series of zoomed images you can increase the number of iterations as you go without loosing continuity. They were created with the new "-d8" colour scheme

Example A large image (it's 5000x3750 pixels!) created using the d8 pallete.

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(c) John Whitehouse 2010 - 2023