Zone Plate

<p>I am getting a little confused by zone plate construction involving a laser printer and overhead transparencies. The various zone plate generators have a spot for focal length-I assume this is for when one is printing the zone plate on plain paper and photographing with a camera? <br>

Am I right to assume that my focal length then would be the distance from the film plane as no lens will be involved with my zone plate construction? <br>

Also, I am right to generate the zone plate to a scale of 1X given there will be no re-photographing in my specific case?</p>

<p>Thanks,<br>

Peter</p>

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