How to create a moire effect?

Moiré is the distortion one can see when taking a photo of a screen or the strange waves when superposing two layers of sheer fabric or mesh. How does this optical illusion happen? And moreover how to recreate it?

Moiré is an optical effect that appears when two grids or lines are superposed.

 

The adjacent fine lines are perceived by our eye as a new shape.

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Here, the two layers of lines produce new dim and light lines when superposed at a certain angle.

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You might get by now that in order for this to work the superposed patterns must be similar for the effect to work. Indeed, the effect works when the set of lines or grid on the two layers just slightly different in size, spacing or angle.

 
 
 

In our watch, you can see this effect when darker lines appear for a brief moment when the two hands are at a certain angle:

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In this more elaborate example, this effect is used to create an animation. As the moving layer lines blend in shapes with the static layer lines over and over again along the way, we perceive it as a motion of these shapes.

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How did we do this? We simply squished down our logo (sorry for typographs out there) to roughly fit the thickness of one of the black stripe from the second layer. There are obviously mathematical equations behind it that you can find on Wikipedia but we enjoy the experimentation phase as it produces fun visual effects.

 

After a few tweaks, we managed to get the right logo proportions inside the moire effect. When we change the lines spacing but not their thickness, it affects the shape and legibility of the logo up to the point that letters are reversed.

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Commonly considered a nuisance in the video and photography world, moire can be used to produce fascinating visual creations. We are obviously obsessed with it!

 
 
 

Possibilities are endless for the creative and patient mind and we will dedicate some future articles to kinetic artists who mastered the moire effect. We hope that this article will inspire you to create your own moire. Feel free to share your creations with us by tagging @hatchwatches or using #hatchwatches .