Actually the distance from your nose doesn’t matter. Think of it this way. When you look at a screen or piece of paper, both of your eyes are trained to converge on the paper or screen. These images have a hidden point somewhere beyond the paper/screen where your eyes can easily focus and see the hidden 3d image.
Hold your hand 3 inches behind your phone. Move your phone away and focus I your hand. Return the phone while maintaining your focus on your hand.
That’s all it takes. Different images have different focal points, so 3 inches might work for this image but not for others. Might have to experiment a bit. But if you can see your hand in focus, then you can also see these images.
Actually the distance from your nose doesn’t matter. Think of it this way. When you look at a screen or piece of paper, both of your eyes are trained to converge on the paper or screen. These images have a hidden point somewhere beyond the paper/screen where your eyes can easily focus and see the hidden 3d image.
Hold your hand 3 inches behind your phone. Move your phone away and focus I your hand. Return the phone while maintaining your focus on your hand.
That’s all it takes. Different images have different focal points, so 3 inches might work for this image but not for others. Might have to experiment a bit. But if you can see your hand in focus, then you can also see these images.