Don't need to print out the stereograms in colour black and white works just fine. It's a nice tool to play with these 3-D images to help you keep to the blip page if you are able to see it.
I am able to see blip when I cross my eyes a bit and than the cylinder is not empty, but it contains text.
That's correct.
As soon as I move a right page it desapites immediately, so that is probably wrong blip
Probably the right blip. Since photofocus is a new skill naturally the blip page will disappear as you slip back into normal focus. Play with stereograms, and you will find that the blip page will become much more steady and disappear less.
AlexK
