Perfect projector

Thread Starter

Tryui

Joined Sep 20, 2021
125
hello gentlemen, I have a small problem, so is there a projector that can cover all degrees of opening of the human eye? in the sense that when we turn on a light bulb a few meters in front of us, we see the light but also other objects that are close to it, so it does not cover all the degrees, but if we bring it closer and closer to the eyes it occupies a greater portion of degrees, not I know if I have made myself clear. So there is a projector that, if pointed at my face or eyes, covers all degrees of sight, making me see only its light and nothing else?
 

Audioguru again

Joined Oct 21, 2019
5,162
I do not know why you want to focus a light beam into a very narrow beam so that it does not light up things that it is not pointed at.

Usually a light beam is wide so that each small amount of it is only a small percentage of the total beam power, but focusing the beam to be narrow concentrates all the light. The concentration of light will blind you permanently. A laser pointer will do it.
 

Thread Starter

Tryui

Joined Sep 20, 2021
125
I do not know why you want to focus a light beam into a very narrow beam so that it does not light up things that it is not pointed at.

Usually a light beam is wide so that each small amount of it is only a small percentage of the total beam power, but focusing the beam to be narrow concentrates all the light. The concentration of light will blind you permanently. A laser pointer will do it.
first of all thanks for your answer, no actually I know very well that the laser hurts and it was just an example that I wanted to do. in fact, in the title of the thread I wrote projector for this very reason, in fact I want to know if there is a technology capable of projecting an image or video in the eyes so that they occupy the entire field of view and so you only see the image and not what it is around. nothing comes to mind also because when I point a laser I can see what is around me, the only method that comes to mind is like when we approach an object more and more towards us, and therefore occupies more and more field of view so this could be a good way, what do you think?
 

MisterBill2

Joined Jan 23, 2018
13,115
Personal viewing glasses have been around for a while and none of them project into the eye directly. There is a very good reason for that, it is far to easy to do instant permanent damage to the eye.
SO THE WHOLE CONCEPT IS VERY DANGEROUS!!!!
At least as unsafe as non-mains-isolated high voltage power supplies.
 

Ya’akov

Joined Jan 27, 2019
6,552
With binoculars and telescopes there is a measurement called exit pupil. This is the size of the circle of light exiting the ocular (eyepiece). It is important because it determines the effective light gathering of the instrument.

The dark adapted eye is ~7mm. The exit pupil is calculated by dividing the objective (front) lens size in mm by the magnification of the system in mm. So, a pair of 7x50 night glasses has an exit pupil of about 7.14mm, or a little larger than the biggest the pupil can get. This is why they are called night glasses, because they gather the maximum amount of usable light. If you increase magnification you also need to increase objective size if you want the same effective light gathering.

So the idea here is that this is you ”projector” in reverse. If you want to completely fill the field of view (fov) of the veiwer you need a 7mm circle of light exactly over and perfectly parallel to the pupil. But this is where your idea becomes very difficult.

Human eyes are never still, in fact if you stare at one point you begin to lose the ability to see things in the center of the fov as the fovea becomes saturated. The way we actually see is to constantly dart our eyes around then the brain composes that data into a coherent, stable image. (In fact, our brains even fill in the peripheral vision with what “should” be there based on memory and expierence, even if it is not really there.)

So, becasue you need to cover the entire pupil as soon as the eye moves so the pupil is not parallel to the projector’s circle of light, you can’t do that any more. Think about what it is like to look into binoculars, you have to keep your eyes straight ahead into the oculars or there is vignetting (the appearance of a circle of the image, or part of one, against black).

In the bincoulars we effectively affix them to our heads so if the head moves the relationship of the eyes to the binoculars is constant. That makes it possible for the brain to accommodate the very small local field of view and so wiggle the eyes as usual but in a very constrained way. Yout projector’s circle of light does not have a fixed realationship to the head, eye, and pupil so as the head is turned it won‘t be parallel any more.

In the end this only stands a chance of working if the person holds their head and eyes almost completely still which would be very hard to do. So, even with other challenges concerning projecting the 7mm circle of light it seems dead in the water from the start.

[EDIT: typo repair]
 
Last edited:

Thread Starter

Tryui

Joined Sep 20, 2021
125
With binoculars and telescopes there is a measurement called exit pupil. This is the size of the circle of light exiting the ocular (eyepiece). It is important because it determines the effective light gathering of the instrument.

The dark adapted eye is ~7mm. The exit pupil is calculated by dividing the objective (front) lens size in mm by the magnification of the system in mm. So, a pair of 7x50 night glasses has an eig pupil of about 7.14mm, or a little larger than the biggest the pupil can get. This is why they are called night glasses, because they gather the maximum amount of usable light. If you increase magnification you also need to increase objective size if you want the same effective light gathering.

So the idea here is that this is you ”projector” in reverse. If you want to completely fill the filed of view (fov) of the veiwer you need a 7mm circle of light exactly over and perfectly parallel to the pupil. But this is where your idea becomes very difficult.

Human eyes are never still, in fact if you stare at one point you begin to lose the ability to see things in the center of the fov as the fovea becomes saturated. The way we actually see is to constantly dart our eyes around then the brain composes that data into a coherent, stable image. (In fact, our brains even fill in the peripheral vision with what “should” be there based on memory and expierence, even if it is not really there.)

So, becasue you need to cover the entire pupil as soon as the eye moves so the pupil is not parallel to the projector’s circle of light, you can’t do that any more. Think about what it is like to look into binoculars, you have to keep your eyes straight ahead into the oculars or there is vignetting (the appearance of a circle of the image, or part of one, against black).

In the bincoulars we effectively affix them to our heads so if the head moves the relationship of the eyes to the binoculars is constant. That makes it possible for the brain to accommodate the very small local field of view and so wiggle the eyes as usual but in a very constrained way. Yout projector’s circle of light does not have a fixed realationship to the head, eye, and pupil so as the head is turned it won‘t be parallel any more.

In the end this only stands a chance of working if the person holds their head and eyes almost completely still which would be very hard to do. So, even with other challenges concerning projecting the 7mm circle of light it seems dead in the water from the start.
wow yakov your answer deserves an award, you are very knowledgeable in this topic, I have read the post many times, but I have to reread it other times to understand all these notions that are new to me. If we think absurdly cue the pupil stays still since he has to see something that interests him (video, film), and he has to do it for a few seconds maybe 15 seconds, could it be possible to do it? I'm basing myself on your last statements since the first part is a bit difficult to understand, also because being Italian the translation is a bit cloudy. For the head obviously cannot be fixed to the head because it is projected. what do you think for a few seconds the eye keeps the focus?
 

Ya’akov

Joined Jan 27, 2019
6,552
wow yakov your answer deserves an award, you are very knowledgeable in this topic, I have read the post many times, but I have to reread it other times to understand all these notions that are new to me. If we think absurdly cue the pupil stays still since he has to see something that interests him (video, film), and he has to do it for a few seconds maybe 15 seconds, could it be possible to do it? I'm basing myself on your last statements since the first part is a bit difficult to understand, also because being Italian the translation is a bit cloudy. For the head obviously cannot be fixed to the head because it is projected. what do you think for a few seconds the eye keeps the focus?
Stare at something moderately bring in the room with you and don't move your eyes at all—for a timed 15 seconds.

Tell me what you think.
 

Ya’akov

Joined Jan 27, 2019
6,552
wow yakov your answer deserves an award, you are very knowledgeable in this topic, I have read the post many times, but I have to reread it other times to understand all these notions that are new to me. If we think absurdly cue the pupil stays still since he has to see something that interests him (video, film), and he has to do it for a few seconds maybe 15 seconds, could it be possible to do it? I'm basing myself on your last statements since the first part is a bit difficult to understand, also because being Italian the translation is a bit cloudy. For the head obviously cannot be fixed to the head because it is projected. what do you think for a few seconds the eye keeps the focus?
I re-read my first post and found two typos that would have been untranslatable. I don't know if it is any easier to understand now.
 

Thread Starter

Tryui

Joined Sep 20, 2021
125
Stare at something moderately bring in the room with you and don't move your eyes at all—for a timed 15 seconds.

Tell me what you think.
thanks yakov for your availability I continued to do research to deepen your message and it seems to me a really extraordinary idea. So I didn't say the 15 seconds without a reason, but I said 15 precisely because 15 seconds are the time a person is able to keep concentration (perhaps you had left out of this topic), However I followed your advice and I can without so much effort to be able to keep the eye fixed on a letter of the alphabet for 15 seconds on a dot of 1 mm ^ 2 at a distance of 40 cm. I also thought that one of the problems could be focusing, and in this case wandering around the internet it came to my mind to use a gas or ultrasound directed on the face in order to create a surface that can act as a display panel or slow, what do you think? this is just an idea, however I hope you can continue to help me also because we have a clear goal
 
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