It's all done with mirrors... #vrheadset


 

I'm seeing a new style of VR/smartphone headset that appears to
use mirrors. Here are three examples I've found on Amazon:

$45 https://smile.amazon.com/dp/B07ZZ5C8C5
$56 https://smile.amazon.com/dp/B07WJZLLWP
$79 https://smile.amazon.com/dp/B082MFFMYR

And then there are this folding VR/smartphone viewers:

$41 https://smile.amazon.com/dp/B0817W2NXZ
$42 https://smile.amazon.com/dp/B07VPK26SV
$51 https://smile.amazon.com/dp/B07BH4QQJC
$51 https://smile.amazon.com/dp/B0817X1HYW
$52 https://smile.amazon.com/dp/B07P2SJD4Q
$56 https://smile.amazon.com/dp/B0825ZRHHR
$57 https://smile.amazon.com/dp/B082HG1WDS
$61 https://smile.amazon.com/dp/B07NY6NC65
$62 https://smile.amazon.com/dp/B07TLLHQ6T
$64 https://smile.amazon.com/dp/B07WVG9JHW
$70 https://smile.amazon.com/dp/B081L9NNB3
$74 https://smile.amazon.com/dp/B07L6FG1MJ
$74 https://smile.amazon.com/dp/B07PM6DYSK
$75 https://smile.amazon.com/dp/B07L75323Z
$75 https://smile.amazon.com/dp/B082HD22KD
$86 https://smile.amazon.com/dp/B07ZTB1WJ3
$90 https://smile.amazon.com/dp/B07JV9SS56
$95 https://smile.amazon.com/dp/B07THJBTMB

I have not carefully compared any of these to each other to make
sure that in both cases they are selling the exact same thing.

Given that none appear to be available direct from Amazon, with
free return shipping, I'm a bit reluctant to give any of them a
try. But these do look interesting and there certainly seems to
be great interest in VR in China. (I assume that's where these
are coming from.)

...BC


ron labbe
 

I'm seeing a new style of VR/smartphone headset that appears to
use mirrors. Here are three examples I've found on Amazon:

$45 https://smile.amazon.com/dp/B07ZZ5C8C5
WOW! Bill, that's VERY interesting! A totally different design... it doesn't actually make sense to me, for without lenses you're trying to focus on something that is VERY close. Also, you're not "enclosed" so the distracting world is still there. Nevertheless, I simply have to order one of these to check it out (and have a sample)! Thanks!

ron labbe


turbguy
 

Don't expect it to be stereoscopic (unless you utilize a "glasses free" display).  It appears to use a curved mirror (like those used at make-up tables) to magnify the view.

It "might" work for glasses-free displays if the distances/magnification works out.

Let us know your results!

Wayne


Mr peter homer
 

I'm seeing a new style of VR/smartphone headset that appears to
use mirrors. Here are three examples I've found on Amazon:

$45 https://smile.amazon.com/dp/B07ZZ5C8C5
WOW! Bill, that's VERY interesting! A totally different design... it doesn't actually make sense to me, for without lenses you're trying to focus on something that is VERY close. Also, you're not "enclosed" so the distracting world is still there. Nevertheless, I simply have to order one of these to check it out (and have a sample)! Thanks!

ron labbe



Because a couple of mirrors are involved the optical path may be at the minimum distance for clear vision if you do not wear eye glasses
also one of the mirrors seems to be curved so there could be some fixed focus there, not sure how you could adjust for individuals includin eye lass wearers for reading distance ( like myself  ). Does not seem to be anyone ships to my area so I can not get one to try out with a     glasses free display like my King 7s or 3DS XL. 

Peter Homer


Oktay
 

.>>.. it doesn't actually make sense to me, for without lenses you're trying to focus on something that is VERY close.<<

With the two mirrors that break the longer light path, you effectively will not be focusing on something very close.

Oktay


Art Clark
 

As a guess, it looks like about 9" to the first mirror, then 4" to the second one, then 4" to the phone. So maybe 17" total image path?  That sounds doable.

Art



On 12/22/2019 6:48 AM, akdens2 via Groups.Io wrote:
.>>.. it doesn't actually make sense to me, for without lenses you're trying to focus on something that is VERY close.<<

With the two mirrors that break the longer light path, you effectively will not be focusing on something very close.

Oktay


Bill G
 

On one of the Amazon links provided, it stated the focal length (eye to target distance) is 125mm, or 5inches...that is VERY close focus.  My guess is, the mirrors have correction built into them, similar to a 5x bathroom mirror... if that is the case, its an interesting concept, I would be curious how well it works.  If it does work well, this premise has potential for a two phone system, polarized with 50/50 mirrors.

On Sun, Dec 22, 2019 at 6:48 AM akdens2 via Groups.Io <akdens2=yahoo.com@groups.io> wrote:
.>>.. it doesn't actually make sense to me, for without lenses you're trying to focus on something that is VERY close.<<

With the two mirrors that break the longer light path, you effectively will not be focusing on something very close.

Oktay


John Clement
 

This is true only if the mirrors also have focusing.  To get a 7 ft light path in 6 inches you would need many mirrors.  With plane mirrors the light path for focusing is exactly the distance the light travels.  There was a toy 3D camera that used plane mirrors to make side by side negative, but it also had a lens.

 

John M. Clement

 

From: main@Photo-3d.groups.io <main@Photo-3d.groups.io> On Behalf Of akdens2 via Groups.Io
Sent: Sunday, December 22, 2019 8:48 AM
To: main@photo-3d.groups.io
Subject: Re: [Photo-3d] It's all done with mirrors...

 

.>>.. it doesn't actually make sense to me, for without lenses you're trying to focus on something that is VERY close.<<

 

With the two mirrors that break the longer light path, you effectively will not be focusing on something very close.

 

Oktay


John Clement
 

It depends on your ability to focus.  I can do any distance with my progressives, but I have read complaints about viewers that bring things too close.  That distance is made for the nearsighted, or the young with very good accommodation.  In either case good viewers must have focus adjustments, which you can not have with a couple of plane mirrors.  However if one is a concave mirror you can have an adjustable viewer.  Mirrors should minimize the color fringing introduced by the chromatic aberration of conventional lenses.  High power plastic lenses tend to have a lot of distortion like old cheap window panes.  I lived in a house with that type of pane.

 

John M. Clement

 

From: main@Photo-3d.groups.io <main@Photo-3d.groups.io> On Behalf Of Art Clark via Groups.Io
Sent: Sunday, December 22, 2019 9:07 AM
To: main@Photo-3d.groups.io
Subject: Re: [Photo-3d] It's all done with mirrors...

 

As a guess, it looks like about 9" to the first mirror, then 4" to the second one, then 4" to the phone. So maybe 17" total image path?  That sounds doable.

Art

 

 

On 12/22/2019 6:48 AM, akdens2 via Groups.Io wrote:

.>>.. it doesn't actually make sense to me, for without lenses you're trying to focus on something that is VERY close.<<

 

With the two mirrors that break the longer light path, you effectively will not be focusing on something very close.

 

Oktay

Attachments:


Depthcam
 

On Fri, Dec 20, 2019 at 04:42 PM, Bill Costa wrote:
I'm seeing a new style of VR/smartphone headset that appears to
use mirrors. Here are three examples I've found on Amazon:
These are actually not new by any means. I have seen them on the net since around 2016.  First of all, they are not "VR" but "AR".  What that essentially means is that they project a virtual image into your immediate environment by reflecting the display of your phone into a sheet of glass that superimposes that image on the real world in front of you.  For that to be efficient, the subjects on your display should be surrounded in black and you should view your content in a dimmed-down environment.

The problem is that if your content is a video clip or still, it will not integrate into your surrounding independently of your head movements but will just remain in the same position in front of your eyes when you move your head.  For this to be more convincing, there would need to be an app that scans your environment and then positions projected 3D objects within it.  And that is where the way-more-expensive AR glasses come in - such as the Magic Leap or the Hololens - costing several thousand dollars.  But there are some AR apps available that do allow some form of interaction with those lower-cost viewers.

So far as I can tell from the pictures in your link, those ones are not stereoscopic.  However I have seen some that are and that feature two convex mirrors so as to project a 3D image in your environment when an SBS clip is loaded.

Last year, a Dutch company called Aryzon had a successful Kickstarter campaign for a slightly different version of this approach in the form of a cardboard viewer with a similar reflector.  This year they just introduced a lighter pop-up version that currently sells for 15 euros (shipping extra).  Again, it's not clear if this is 2D or 3D but there are no optics involved - just your phone being reflected by a mirror and a sheet of transparent material.

https://shop.aryzon.com/products/aryzon-pop-up

What's unique about this company is that they are very much active in developing apps for their system and also offer links to apps that are compatible with it.

https://www.aryzon.com/ar-content

If you are not sure whether you want to get involved with AR, then that surely is an inexpensive way to try it out.

And if you feel like me that VR and AR headset have a serious shortcoming in the form of their bulk, take a look at this newly announced (and tested) set of ultra lightweight 1080p AR glasses announced for 2020:

https://www.youtube.com/watch?v=M9A9u-lwjTs

Not cheap, but way more affordable than Magic Leap.

Some pretty amazing things are coming our way !

Francois






Depthcam
 

Just to update my last post:  I did further research on the Aryzon AR viewer and it turns out that it is indeed stereoscopic.  The way it manages to allow the eyes to focus on the real environment at a distance as well as the phone display at very close range is by the use of two very thin Fresnel lenses placed between the two reflecting surfaces (a mirror at the bottom and a half-silvered one at the top).  Other similar viewers use instead two concave reflectors that act as focusing lenses for the phone display while the eyes observe at the same time the immediate environment.

AR can produce some interesting special effects in 3D.  However regular stills or clips won't benefit from being viewed this way simply because the surroundings - unless quite dark - will cause your images to appear translucent and thus lack in contrast.

Francois


Depthcam
 

The viewers in Bill's link however appear to be designed mainly to "project" the phone's display and make it appear to be a large screen some distance away.  It has one single curved reflector so it is not 3D.  However, it's quite possible that mounting a glasses-free 3D phone in this viewer might produce an illusion of watching a large glasses-free 3D TV.

It might be worth testing this out.

Incidentally, I saw another device based on the same principle but that is instead a tabletop viewer that magnifies a phone's display using concave reflectors.  It's not a new idea.  Back in the fifties, there were viewers with concave mirrors designed to produce a similar effect.

Francois


ron labbe
 

Don't expect it to be stereoscopic (unless you utilize a "glasses free" display).  It appears to use a curved mirror (like those used at make-up tables) to magnify the view.

It "might" work for glasses-free displays if the distances/magnification works out.

Let us know your results!
Doesn't look like that to me, at that distance it would be really distorted. Good thought though! In any case, after I ordered it, I got the tracking for delivery in January. THEN an email saying it's discontinued, the new model is this https://smile.amazon.com/Funiee-Virtual-Headsets-Smartphones-Adjustable/dp/B07ZX5ZL5D/
So I really don't know if the discontinued one is actually on it's way!?? Waiting for response.

ron labbe


ron labbe
 

With the two mirrors that break the longer light path, you effectively will not be focusing on something very close.
Gee, how long is the light path? 6-8" instead of 3"? That's still too close (without some kind of lens) for most people.

ron labbe


John Clement
 

While this might work, there are problems.  Well made glasses free display have a sweet spot in horizontal angle and in distance from the screen.  This latter sweet spot is a fixed distance.  The distance between eyes may cause problems with these sweet spots so some adjustment of the distance from the screen may be needed.  There is also the problem of a slight horizontal misalignment between the lenticular film or barrier and the screen.  Considering all of these parameters it is doubtful that it would work.

 

Blowing it up to large size still keeps the angles of the outgoing rays of light the same.  So now it is as if your eyes are closer together looking at the phone.   In normal practice each eye has a separate horizontal sweet spot with a transition in between.  Now your eyes are much closer to the transition between  the sweet spots, so there will most probably be increased ghosting.

 

It is as if your eyes were closer and the phone much closer to your face.  The lens essentially allows accommodation.  Closer to your face would be out of the distance sweet spot.  You would then see transitions across the screen.

 

In either case the lenticular screen cuts the horizontal resolution in half.  Side by side display on a conventional phone actually cuts both horizontal and vertical resolution in half.  Side by side on a glasses free would have ¼ horizontal resolution with a ½ cur in vertical.  However if you could display it anamorphically with 2x horizontal compression on a standard phone and have anamorphic lenses for each eye, you could only lose ½ of horizontal detail.

 

If you want a BIG screen effect from a glasses free phones with minimal sacrifice in resolution the best way to achieve it would be to have a pair of binoculars that could focus on the phone with it held at the correct distance.  Straight binoculars could do the job, but ones that use prisms to change the interocular would pose problems.  The best designed glasses free displays are designed for the average eye separation at a fixed distance from the screen.  So if the optimum distance from the eye is 1ft, the box would have to be 1 ft deep.  There are binocular glasses for people who have severe vision problems that might be used to give you a large screen effect.

 

In this game there is no free lunch.  Glasses free multi person displays should be possible using lasers, but the bandwidth is humongous.  You can’t have low price, convenience, and high resolution together.  I get acceptable viewing on phones with my progressive lenses.

 

John M. Clement

 

From: main@Photo-3d.groups.io <main@Photo-3d.groups.io> On Behalf Of depthcam via Groups.Io
Sent: Monday, December 23, 2019 3:54 AM
To: main@Photo-3d.groups.io
Subject: Re: [Photo-3d] It's all done with mirrors... #VRheadset

 

The viewers in Bill's link however appear to be designed mainly to "project" the phone's display and make it appear to be a large screen some distance away.  It has one single curved reflector so it is not 3D.  However, it's quite possible that mounting a glasses-free 3D phone in this viewer might produce an illusion of watching a large glasses-free 3D TV.

It might be worth testing this out.

Incidentally, I saw another device based on the same principle but that is instead a tabletop viewer that magnifies a phone's display using concave reflectors.  It's not a new idea.  Back in the fifties, there were viewers with concave mirrors designed to produce a similar effect.

Francois


George Themelis
 

This discussion reminds me of a very unusual stereo Realist viewer we discussed about a year ago in photo-3d: Clubman.  Instead of lenses, it uses mirrors.
 
Here are two of my postings regarding this viewer. Others also contributed. David Starkman posted a copy of the instructions.
 
==
 
Hi Guys,
 
A friend of mine gave me the most unusual stereo Realist viewer to sell on ebay. I will give the link in sell-3d, but if you search “Clubman stereo viewer” you will find it.
 
My friend has been 40 years into stereo and has never seen anything like this. He bought it at a camera show ~20 years ago. I have not seen this before either. I don’t think I have seen any Realist viewer that uses mirrors, instead of lenses.
 
So, this “Clubman” viewer looks like a rectangular box of a good size and hefty weight (2 lbs). If I had seen this at a camera show, I would have passed. There is nothing to indicate that this is a Stereo Realist viewer. It does not look like a stereo viewer. I just looks like a box that says “Clubman Kit” plus an address at the bottom.
 
It took me a good 15 minutes to figure out how it works. You put a slide in the slot (which is large for no good reason), open and tilt a little door at the bottom and look through the opening at a slight upward angle.
 
You then see a perfect 3D image.
 
The image is small but very sharp. The viewer will show the widest slides (33mm RBT) without cutout. I showed it my wife, which has hard time using viewers etc., and she was able to see the 3D image right away. She even commented that this would be a good viewer for a beginner because it is so easy to use. It has no focusing, no interocular, because it has NO LENSES!
 
Anyway, it is a very interesting device and I wonder if anyone has seen this before or anything similar.
 
Thanks,
 
George
 
====
 
My understanding is that you can use mirrors or lenses to form an image. Maybe someone with more experience with geometrical optics can help with the light path.
 
It is a sealed box and I don’t want to even think about opening it. Especially after Ron Labbe said he has not seen this before (I thought he had seen everything).
 
From the outside you see nothing.
 
I don’t understand why there are not more mirror viewers out there using the same design. Maybe because mirrors are heavy and expensive, while lenses are small and lead to a simpler design. 
 
For me, it is more of a novelty than a practical viewer. Because the image is small and the viewer is large & a bit heavy. But it is fun to see an image forming seemingly out of nowhere into the “thin air.” It would be interesting to use this design for Medium Format slides as Boris suggested in the MF3D list. I don’t know what the size limits for this design are (if any).
 
George


 

Straight binoculars could do the job ...
So Galilean binoculars (aka opera glasses)... Seems like a funny
idea, viewing a smart phone display from a distance.

You can’t have low price, convenience, and high resolution
together.
The rule for computer hardware is: Good, Fast, Cheap. Pick any
two. Perhaps the version in general for 3D viewers would be
Good, Convenient, Cheap. Pick any two. (Or sometimes pick only
one!)

...BC


Depthcam
 

On Mon, Dec 23, 2019 at 11:06 AM, John Clement wrote:
While this might work, there are problems.  Well made glasses free display have a sweet spot in horizontal angle and in distance from the screen. 
Yes, my thoughts exactly.  That's the big "if".  However, what I found is that the "sweet distance" varies from phone to phone.  So I am curious if testing these with several phones might find one that works.  Also, it might be worth experimenting with a similar light path by varying the distance and size of those reflecting surfaces to see if one arrangement might work.

Francois


Depthcam
 

On Mon, Dec 23, 2019 at 08:08 AM, ron labbe wrote:
THEN an email saying it's discontinued, the new model is this
What he means is that he had a limited number and sold out on them.  Other dealers will have stock of them.

As to that other one on your link, well, that one IS stereoscopic.  It has two separate concave mirrors built inside it and is meant to view SBS content.

Again, I will reiterate that it projects that content in the space in front of you.  So if you mean to watch regular 3D movies or stills, you must do so in total darkness or else the light from your surroundings will cause a strong reduction in contrast and a translucent image.

Francois


Bill G
 

>  If you want a BIG screen effect from a glasses free phones with minimal sacrifice in resolution the best way to achieve it would be to have a pair of binoculars that could focus on the phone with it held at the correct distance.

This is the most mis understood area of 3d viewing.  Many years ago on these forums, I had discussed this in detail.   H-ere is the short explanation again since this topic is heating up again.

        to achieve "BIG Screen effect" as you call it, which is the hardest of the ingredients of the holy grails for 3d viewing, it requires a more lifelike FOV.  Our unaided vision can see approx. 90 deg per eye, more combined with two eyes of course.  Binoculars, are a compound optic, it uses the objective lens to project an image into the an Eye Pieces field stop.  From there, an EP projects the image into your eye.   So the Big Screen effect, which the proper term in the optical design field is AFOV, (Apparent Field of View) is what we are chasing, i.e. a larger AFOV, closer to our unadied vidsion.  It does NOT matter if you view through an EP in a binocular, or EP directly on the image, its the AFOV specification of the EP that determines the AFOV.  Even the FL is irrelevant, as well as the image size.  Its the optic that sets the AFOV, nothing else.

Unfortunately, designing an EP with a wide AFOV close to our unaided eye, would require massive multi element optics, typically about 2"+ wide.  I know, I have designed and built them.  The only commmerically avaialable EP with these wide AFOV are designed for telescopes, and are about 5" long and weigh about 2lbs each, and cost about $800+ each.  I used to own several of these commercially available EP's, and they would make horrible 3d viewing EP's, as the Eye Relief (ER) is so short, (about 10mm) the eye can NOT rotate without vignetting the image circle.  In a telescope, you can stay focussed on the center of the image and move the telescope to scan the scene and maintain the full 90 deg AFOV.   That is not possible with 3d viewers, as you must rotate your eye to scan the scene.  Since the center axis of rotation of the eye is 13mm behind the cornea, you would need a min. of 20mm of ER for such a lens to work for a 3d viewer.  (this assumes no eye glasses) The mix of long ER and wide AFOV is the kiss of death for an optical design.  I spent 3 years trying to acheive this holy grail.  Despite having some of the best lens designers in the country on my team, and using CodeV software on Cray computers, we fell way short of the end goal.  In the end, the MAX we could achieve was 20mm ER, with 55 deg HFOV (best ever in 3d) and a very good MTF required for the high resolution available in MF film.  These prototypes EP's were 1.5 lbs each, had 6 elements, 2 inches wide, and in precision barels due to tight tolerances of the optics.  And cost in Asia, for runs of 500 volume, were $500 each, not amortizing R&D cost.  And still no where near the holy grail.  This IMO represents the shortcoming of all close viewing 3d systems.  If you gain wide AFOV like VR headsets, you compromise the MTF (the ability to transfer contrast from the image to the target, which is the fovea)  You also compromose ER for eyeglass wearers.  This why I mentioned in a previous post, it will take a massive leap in technology, such as nano 3d printing combined with optical design, to make an EP for close 3d viewing that gets closer to the holy grail being discussed here. 

This is the problem with viewing an image close to the eye.  Hence why I mentioned why these mid distance viewers would be ideal, as it eliminates the biggest obstacle - optics to bring the image into focus and accomodate a rotating eye.  With mid distance viewer, you can scan the image by turning your head, reducing optical design to only provide sharp imagery for the foveal projection, which is under 3% of our FOV.   That is very feasible and cost effective for the masses, as well as light weight.  It checks all the boxes for big market success. 


On Mon, Dec 23, 2019 at 9:06 AM John Clement <clement@...> wrote:

While this might work, there are problems.  Well made glasses free display have a sweet spot in horizontal angle and in distance from the screen.  This latter sweet spot is a fixed distance.  The distance between eyes may cause problems with these sweet spots so some adjustment of the distance from the screen may be needed.  There is also the problem of a slight horizontal misalignment between the lenticular film or barrier and the screen.  Considering all of these parameters it is doubtful that it would work.

 

Blowing it up to large size still keeps the angles of the outgoing rays of light the same.  So now it is as if your eyes are closer together looking at the phone.   In normal practice each eye has a separate horizontal sweet spot with a transition in between.  Now your eyes are much closer to the transition between  the sweet spots, so there will most probably be increased ghosting.

 

It is as if your eyes were closer and the phone much closer to your face.  The lens essentially allows accommodation.  Closer to your face would be out of the distance sweet spot.  You would then see transitions across the screen.

 

In either case the lenticular screen cuts the horizontal resolution in half.  Side by side display on a conventional phone actually cuts both horizontal and vertical resolution in half.  Side by side on a glasses free would have ¼ horizontal resolution with a ½ cur in vertical.  However if you could display it anamorphically with 2x horizontal compression on a standard phone and have anamorphic lenses for each eye, you could only lose ½ of horizontal detail.

 

If you want a BIG screen effect from a glasses free phones with minimal sacrifice in resolution the best way to achieve it would be to have a pair of binoculars that could focus on the phone with it held at the correct distance.  Straight binoculars could do the job, but ones that use prisms to change the interocular would pose problems.  The best designed glasses free displays are designed for the average eye separation at a fixed distance from the screen.  So if the optimum distance from the eye is 1ft, the box would have to be 1 ft deep.  There are binocular glasses for people who have severe vision problems that might be used to give you a large screen effect.

 

In this game there is no free lunch.  Glasses free multi person displays should be possible using lasers, but the bandwidth is humongous.  You can’t have low price, convenience, and high resolution together.  I get acceptable viewing on phones with my progressive lenses.

 

John M. Clement

 

From: main@Photo-3d.groups.io <main@Photo-3d.groups.io> On Behalf Of depthcam via Groups.Io
Sent: Monday, December 23, 2019 3:54 AM
To: main@Photo-3d.groups.io
Subject: Re: [Photo-3d] It's all done with mirrors... #VRheadset

 

The viewers in Bill's link however appear to be designed mainly to "project" the phone's display and make it appear to be a large screen some distance away.  It has one single curved reflector so it is not 3D.  However, it's quite possible that mounting a glasses-free 3D phone in this viewer might produce an illusion of watching a large glasses-free 3D TV.

It might be worth testing this out.

Incidentally, I saw another device based on the same principle but that is instead a tabletop viewer that magnifies a phone's display using concave reflectors.  It's not a new idea.  Back in the fifties, there were viewers with concave mirrors designed to produce a similar effect.

Francois