he took a linen cloth, a glass/window pane, some white paint.
he painted a image of a face(represention of christ) on the glass placed the glass over the linen and left it in the sun for ten days.
this did leave a image on the cloth also when the 3d rederation of the cloth was done it did creat a 3d image of a face, its said that this is do to the movement of the sun.
im not saying its a fake ill leave that up to ones own belifes, im just stating what ive seen tonite on the news and it seems very likly to me now that some one back then could have done something like this, then agian maybe not?