yes yes thank you for your valuable answer in fact I had to list them tomorrow, then I also thought about this and it is obvious that the size of the source screen must be about 1 cm and as a source I am unsure whether to use a smartphone or a mini-projector also because, with smartphones are viewers, the only difficulty is to keep the beam tight and increase the brightness as well as focus. then I repeat, I already keep sure that the head does not move, this is not a problem. For holograms there is no problem, there are technologies called displair or holovect that allow me to create a holgram but I will do this by myself. Now it matters to me to finish the project of the projector as soon as possible. So I repeat either smartphone or projector as the source changes little, the problem is the lenses, please help me choose the right ones, so we finish the thread because I'm really tiredYes, you have. But your description is still incomplete. For example, what is the source of the image and what is its size?
To calculate the lenses required, you need to know that information to calculate the projection ratio. Basically, as I understand your problem, you need to project an image of unknown size onto a “screen” of about 0.1” at a distance of 3.28’.
I estimated the screen size at approximately the size of your pupil on your eye. That’s a tiny screen and misalignment of 1 tenth of an inch would not allow the image to be seen. Your viewer must have a very steady head.
Theoretically, perhaps an holographic image might be better, as it’s visible over a broad range of viewing angles. But your “screen” still would have to be small in order to prevent nearby people to see it. Maybe you could get away with 1”… But I am not familiar with holography.