I will pull in quotes from my other various posts on this topic, so you do not need to jump all over the place to follow the previous scattered "thread". Please forgive any duplicate post contents here. I really should have started a new thread to begin with.
UPDATE: Be sure to check out the new "Fresnel Lens Stack Theory of Operation" post (with lens position diagram) here:
http://www.mtbs3d.com/phpBB/viewtopic.p ... 865#p98869
geekmaster wrote:Although I have the recommended 5x lenses, I just tried an experiment with a cheap dollar store "Page Magnifier Bookmark" plastic fresnel lens with fine pitched ridges. It is about 2 inches tall and 6 inches wide. I cut it into 3 pieces each two inches wide and overlapped them (all with ridges toward the eye, no rotation). Then I cut out the corners to fit my nose and inner eye brow. When in focus on my Nexius 7 screen, it completely fills my horizontal FoV, including where my nose should be and as far as I can stretch my gaze away from my nose. That is more FoV than my natural FoV. Although it causes chromatic aberation on text (mostly blue), that is rarely noticeable in a game environment.
I played one of cybereality's Rift-adjusted videos from the Vireo Perception thread at fullscreen on my Nexus 7 (7-inch LCD), and it was great. If you normally wear glasses, but blurriness at the corners is less than from real glasses (even large aviator-style lenses). In fact, after having such a super-normal FoV, it makes me much more aware of my eyeglass frames (and my nose) which are obstructing FoV that I saw inside the game environment. MUCH better than I had expected, and extremely lightweight lenses.
I got the idea from an old "Virtual Reality Construction" book that came with fresnel lenses and a cardboard fold-up frame, which had a string to tape to a CRT monitor so it could hang down against the screen and to use like binoculars on a displayed stereo image. These cheap dollar store lenses are much higher quality (finer pitch) than used in that device.
By overlapping the fresnel outer edges, their extreme offset simulate looking through the edges of the 5x lenses causing more geometric distortion (desirable in this case, pushing the image beyond the nose boundary).
Any perceived distortion is quickly lost in the game environment in my experience, but it could be compensated in software (including shifting blue for chromatic aberration adjustments).
And these lenses are cheap too (only one dollar per eye from my local dollar store).
Here is the lens I used (UPC 731015162413):
http://www.dollardays.com/i789846-whole ... ml?print=1
This is a popular lens available from many stores, but most places sell it in multiples of 24:
http://www.antarespro.com/5977131-item- ... 62413.aspx
I may mount my cut-down fresnel lenses very close to my eyes in modified swim goggles (also available from my local dollar store):
http://www.fishingdiscountdirect.com/pr ... direct.com
And I may try attaching my Nexus 7 to dollar store saftey goggles like these (but they may need a better strap):
http://www.dollartree.com/Tool-Bench-Sa ... /index.pro
geekmaster wrote:My camera battery is dead so words will have to suffice for now.Mel wrote:Interesting stuff, geekmaster. Can you clarify the steps for how you modified the lens? A photo is worth a thousand words
...
I guess it's that 'stacking' thing I'm asking about. You said you cut it into three pieces, so what's the stacking arrangement such that three pieces covers both eyes?
I cut the fresnel portion of the lens into three pieces about 2 inches wide. Then I stacked them with the ruler marks at top and bottom and ridges toward my face. I don't think the stacking order matters, but I stacked them left edge piece, then right edge piece, then center piece (starting from the side closest to the eye). Then I trimmed the edge toward my nose until the lens stack fit comfortably under my eye brow and overlapping the bridge of my nose. Be sure to keep the ridged (non-smooth) side of all 3 lens elements towards your eye. Then do the same with another lens stack for the other eye.
geekmaster wrote:I am surprised at how well it worked with these newer cheap fine-pitched fresnel lenses. By stacking them, I am taking advantage of the extreme off-center distortion from the edges of these 6-inch diamemeter lenses. Due to my stacking arrangement it does not stretch vertically near the edges as much as horizontally, but still it looks amazing, and the correction you used in your "rift-adjusted" video actually shows doorways as rectangular in these lens stacks. There is more chromatic abberation near the edges (mostly blue), but that could be adjusted in software. Even when I rotate my eyes in their sockets (painfully) to their extreme positions, all I can see is video (even where my nose should be), giving me a "supernatural" FoV.cybereality wrote:Sounds good, geekmaster. I always thought that fresnels would work well.
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For low-power devices (no GPU) I plan to use a software displacement map to do the geometric and chromatic correction, like this:
I used displacement mapping like this for animated "magnifying glass" effects back in the early 90's, when 360x480 256-color VGA (Michael Abrash's "Mode X") and 386 CPUs were state-of-the-art. It should work well on low-power devices to correct for lens distortion.
BTW, the fresnel lenses that came with the cardboard "HMD" in the "Virtual Reality Creations" book were much coarser pitch than these dollar store fresnel lenses, and consequently did not work as well. Here is that book:
http://books.google.com/books/about/Vir ... AIAQAAMAAJ
And these are listed at Amazon as "new", so may even come with the fresnel goggles:
http://www.amazon.com/gp/offer-listing/ ... dition=new
I have been into 3D for about 55 years now. It was always a big thing in my family. I have my grandmother's stereopticon viewer and a large collection of 3D cards for it:
I was thinking about trying to stick my Nexus 7 into my stereopticon in place of a 3D card. A classic steampunk HMD, for sure...
geekmaster wrote:I need to get another fresnel magnifier. I only have a fresnel lens stack for one eye. I just tried the Fov2Go demo on my Nexus 7 (held in my left hand), while holding the lens stack (with taped top and bottom edges) to my right eye (close enough to brush eyelashes on it). With my left eye closed, I turned slowly around while standing, which navigated me around in the VR space of the Fov2Go demo. When turning at a casual pace, such as when exploring the scenery, it was very immersive without noticable latency. However, when turning quickly, the latency caused an immediate dizzy feeling that persists several minutes later (along with a feeling that I was punched in the stomach). It does not help that I just ate a meal a few minutes before trying this demo and I still have a full stomach.
Now, turning my head OUTSIDE the VR environment increases my vertigo. I am normally not prone to motion sickness, so perhaps the "supernatural" FoV increased my proximity to the "uncanny valley" (which is known to cause queasiness)...
I will need to turn slowly when using the Nexus 7 internal IMU (or at least the Fov2Go implementation of it). Now, I am anxious to get another fresnel magnifier, and to construct a cardboard and tape mount and shroud to hold the lenses in place at the correct position in front of my Nexus 7 display. I will try using dollar store safety goggle first, before purchasing more expensive sky goggles.
The goal here is to create a template for an extremely inexpensive add-on for an Android tablet, using locally available cheap components. Just for "fun", you know?
Then later I will use my 5x loupe aspheric lenses (if I can remember where I put them "away").
geekmaster wrote:How much it stretches the image depends on how close it is to your eye. Mine focuses with the triple stack at less than two inches, but I am near-sighted (myopic). YMMV. For a smaller display you may need another lens element for greater magnification.MSat wrote:Very interesting, geekmaster! I'm trying to wrap my head around the premise of the stacked fresnels, and why it should work, but I might just have to stop by the dollar store tomorrow and see what they got to try it out for myself. What is your thought on image quality? Does it remain clear overall? Also, if they're giving a super wide FOV on a 7", would they still work well on smaller displays (I suppose this really depends on the fresnel design, correct)?
At the "sweet spot", the image is surprisingly good with sharp focus. With different fresnels, it may not be as good a focus. I have seen many fresnel magnifiers with much coarser pitch (sginificantly fewer ridges per inch). I recommend the ones I showed in my first post on this, but at least get the finest pitch fresnel magnifier that you can find.
The angle of the lens stack is important too -- it should be roughly parallel to the screen surface (but adjust it for best image). And very close to your eye, which required trimming to clear your nose and inner eyebrow ridge. And ridges inward toward the eye for all lenses too...
The lens stack using the outer edges of the 6-inch lens scretches the image horizontal edges much more than vertical. However, and my optimum focus, the vertical (just barely) covers my full FoV. I actually lose a small amount of the horizontal image, but nothing that detracts from immersion.
I will take some pictures of the lenses and through the lenses when I get around to charging my camera battery.
geekmaster wrote:The chromatic aberration is mostly at the edges of the total FoV, with blue stretched farther than other colors. This causes objects to have a bluish inner edge and yellowish outer edge, mostly visible on text or other sharp high contrast content. Not very visible on "realistic" scenery such as in games. And it does not detract significantly from immersion, which is the main goal here. This is not a desktop environment. And if required, the chromatic aberration could be compensated in software.MaterialDefender wrote:@Geekmaster: how bad is the chromatic aberration with fresnels? I already wondered whether fresnel lenses might make sense some time ago, but came to the conclusion that CA would most likely be much worse than with good aspheric lenses.
The centers are sharp and devoid of chromatic aberration. And with head tracking, the edges are just peripheral vision and not a big problem. Just having moving VR content there (even if distorted) is vastly superior than having that portion shrouded from view. You really need to experience it. After having a "supernatural" FoV, going back to normal vision makes you very aware of the visibility of your nose, eyebrows, and cheeks as you roll your eyes around in their sockets. All those natural occlusions contain VR video with my fresnel lens stacks close to my eyes, and although those boundary pixels are somewhat distorted, they ARE part of the peripheral vison and contribute greatly to immersion.
The key to this is the very fine pitch (ridges per inch) of the fresnels I used (and recommended above). These work MUCH better than attempts in the past that used much coarser pitch (fewer ridges per inch) than these. I believe that the focus is better and the chromatic aberration is less annoying with these newer cheaper fresnel magnifiers.
geekmaster wrote:To get maximum FoV, the fresnels are trimmed to fit under my eyebrow ridges, and against the side of my nose. A pair of lenses actually touch together on the upper nose bridge (but below the center of the eyebrow ridge).MaterialDefender wrote:You make me really curious... Since I'll disassemble my build anyway to put in new lenses, I guess I will try to find some good fresnels too for testing.
The images are stretched far enough the even with full FoV there is no visibility of the other half of the screen (but the outer corners are outside the FoV). When inside a game, it really is an amazing experience. Like I said, this arrangement provides a "supernatural" (beyond natural) FoV. Cutting down aspheric lenses may not provide this experience. I think it is the stacking of the outer 1/3 of 6-inch lenses with the center 1/3 that contributes to the extraordinary horizontal FoV.
Using aspherics may provide a better quality image, but at a reduced FoV. Immersion is more FoV dependent than image quality dependent, in my experience.
I have yet to try a pair of lens stacks for a stereoscopic test, but I do not see why it should be any problem.
Beware that the lens stacks must be in the "sweet spot" (try adjusting their position) or the result will be unsatisfactory. My fresnel lens stack may be optimized for my near-sighted vision, so YMMV.
If others try this, please report back...
geekmaster wrote:For an understanding of why these stacked fresnel elements work like this, look up information on "eccentric fresnel". I am using one outer 1/3 of a 6-in lens to stretch the inner side of the image behind my nose. The other outer 1/3 stretches the outer edge of the FoV so all you see is pixels even when painfully rolling your eyes to the outer limits. And the inner 1/3 adds to that, and also stretches the vertical FoV above my eyebrows, and below my cheeks. It is like slicing smaller lenses from the outer edges of a large 6-inch lens, resulting in a large sidewayes stretching of the FoV.
geekmaster wrote:Cool! I need to find my camera battery charger now...PalmerTech wrote:Some pictures would be great! I have been messing around with things like this, but I want to test your actual setup. I have the fresnel lenses you used on order, should be here soon.
EDIT: Found it. Charging...
geekmaster wrote:As I mentioned earlier, I cut the 6-inch wide lens into 3 2-inch wide lenses then stacked them face-to-face with the ridges all toward the eye. I trimmed the edge against my nose and eyebrow so it all touches the skin of my nose, under my eyebrow, and my cheek.3dvison wrote:That would be great, because I am not sure where the cut edges go ? Are the three stacked one on top of the other or are they butted edge to edge or even if they are shifted a little left and right, can't you then see the edges of the center fresnel ?
I just looked into a mirror while holding my lens stack to my face and I see that it touchs the corner of my nose where it joins the cheek above my lip.
geekmaster wrote:Yes, that is the one that gave me the idea to try this. I still have it, but the lenses fell out of it. They are around somewhere. That tab on top has a red string tied to it (included in the kit), which gets taped on top of the CRT so that you can hang it down over the screen and use it without holding it, or place it on top of the CRT when not using it. It worked fairly well, but you had to lean into it to use it, and you had to size and center your 3D image pair to fit into it.Fredz wrote:This one I guess ? :geekmaster wrote:I got the idea from an old "Virtual Reality Construction" book that came with fresnel lenses and a cardboard fold-up frame
Those were very coarse pitched fresnel lenses, and the ones I used for this experiment are very fine pitched (so much better image). Also, to get the maximum area of the screen in focus, I am holding them roughly parallel to the screen surface.
I just bought 16 more lenses to play with. I just cut one up and got a couple of photos before my battery was dead again. I lost my original charger while travelling, and this replacement charger takes forever and does not seem to give a full charge...
I have a photo of it held up to my left eye, taken while looking in a mirror, so you can see how it touches the underside of my eyebrow ridge, and the side of my nose down to my cheek, and part of my cheek... I need to stack them together and trim their edge to match the curve now cut into one of them, then take more photos.
Now, I need to charge my camera battery overnight, and I need to find my microSDHC card reader so I can post the photos I have thus far...
geekmaster wrote:I will have to try that. I started with one fresnel magnifier. It is cut at the 2 and 4 inch marks, just like yours. It works well enough, but perhaps your stack of 3 centers would be even better...3dvison wrote:OK, I my be slow on the up take, but this is what seems to work for me, and it may well be what has been said here all along but I just did not understand it.
Found what seems to be very close to the same lenses at Office Depot.
For me using the center portion is what gives the best image. So if you wanted a 2inch dia lens you would start at the 3inch mark which is the center of the 6inch lens and go 1 inch left of the 3inch mark and cut and 1 inch right of the 3inch mark and cut.
So I needed 3 full 6inch lenses to make 1 lens. The lens is made from 3 identical lenes all cut from the center portion of the larger 6inch fresnel..
Using the eccentric (off-center) edges requires keeping the ridges toward the eye. Otherwise the image distortion is not correct to compensate for the Rift-adjusted images.
With eccentric lense, the image can stretch beyond normal facial occlusions such as the nose. It that the same for only using lens centers?
geekmaster wrote:Try the eccentric (edge) portions in your stack, with the ridges facing toward your eye. Be sure to cut notches for your nose and eyebrow ridge in the inner edges (but not too much or you lose too much of the outer edge). I was actually holding mine below the eyebrow inward toward the eye. The key to stretching half of a 7-inch screen to full FoV is getting it very close to the eye, which requires trimming a little to fit the nose and inner eyebrow ridge...3dvison wrote:Ah Ha,
My stack has the ridges facing away from the eye.
I was testing it with pre-warped Rift photos.
The advantage of this stack over a regular round lens, is the rectangular shape, you dont feel like you are looking through a port hole.
Because the lens portion of my magnifiers is a bit larger than 6-inches, my elements were about 1/8-inch wider than 2-inches.
I still think the eccentric portions from the outside of the 6-inch lens are important to get the full FoV that I am describing. One side stretches the inner image beyond the nose with none of the other image visible (and not even the nose visible). The other side stretches the outer image to the edge of the lens stack without showing the left border of the video image. The center part gets rid of the top and bottom margins...
I have not tried 3 centers yet. I bought 16 more magnifiers so I will try various arrangements to see if I can improve on it.
geekmaster wrote:My camera battery is charged now, so I should get the photos that Palmer requested posted some time this weekend (I hope). Demands on my time have been just nuts lately...Zoide wrote:I can't wait for Palmer to buy into geekmaster's Fresnel lens idea so we can have a consumer Rift with superhuman FoV![]()
Palmer: Any news regarding your experiments?
Hopefully those photos will help Palmer (and others) to duplicate my results. I tried cutting another lens stack to fit my nose more snuggly, but that reduced lens coverage of my outer peripheral vision. Getting (almost) full coverage at the outer edges requires the lens stacks to be positioned just right, so they may not provide total FoV for everybody (depending on facial features).
What I would really like to try is a custom acrylic lens that can duplicate my fresnel lens stack, but with superior image quality (necessary when the Rift gets a higher resolution display).
geekmaster wrote:That makes sense. I cannot look up past about 45-degrees before I see my eyebrows, but I have to look down at a very steep angle (about 80-degrees) to see my mustache. The Rift photo looks about right for those vertical viewing angles. That is also how I held my Nexus 7 while testing my fresnel lens stacks, so that I could fill that FoV (and somewhat beyond).Diorama wrote:I've seen others mention that the bottom of the screen being invisible is really important for immersion; in fact in some of the official oculus dev kit photos it looks like they may have also placed the screen slightly offset down:
geekmaster wrote:I did an experiment with fresnel lenses, where I stacked 3 elements such that the left and right edges of the images are stretched, then I trimmed the inner edge so it fit onto the upper bridge of my nose but under the inner eyebrow ridge. That places them very close to the eye, so the eyelash brushes them. The side of the fresnel lenses with ridges must be toward the eye on all 3 lenses in the stack. It gives me a view of my 7-inch Nexus 7 screen (showing a rift-compensated video), which extends beyond my normal visual borders. I can see video where my nose should be, and even at the extreme limits of rotation of my eyes. In fact, there are pixels everywhere I look with no obstructions (well beyond the limits of my eyeglasses for my normal vision).
The inner edge is cut somewhat similar to what PasticheDonkey showed:
but the other edges are more rectangular so they cover all of my field of view.
If you can get the lenses close enough to your eyes (using a flat or concave inner surface), you can have a FoV beyond what is natural. Supernatural FoV.
geekmaster wrote:The perceived chromatic aberation is mainly blue (and mostly visible on text displays). In a 3D game it is rarely noticeable except when you look for it. And yes, you could adjust for it in software (as mention in the other thread).PasticheDonkey wrote:...
would maybe have to render a nose and brow etc. i think chromatic abrasion could be sorted in software as well.
Unlike your lens images, mine have the tops trimmed flat so the fit below my eyebrows so I can get them very close to my eyes. They must be very close to fill the entire FoV even with extreme eye rotation. In my case, I am near sighted so it is all in focus even with complete FoV coverage. Pulling the lenses away from the eye even a small amount reduces the FoV coverage quite a bit. If my focus does not work for you, you may need to add another lens element to the stack.
Stangely, after using this for larger than normal FoV, taking this off makes me very aware of natural vision occlusions such as my nose, eyebrows and cheeks (but especially my eyeglass frames and unfocused FoV outside them). Normal vision feels restriced and limited after such a "supernatural" FoV experience.
geekmaster wrote:Moving the screen away brings the screen edges into your FoV. Better to increase magnification and lose a few pixels around the edges than to bring unnatural occlusions into the picture.PasticheDonkey wrote:in that case moving the screen rather than lenses could adjust focus.
As it is, the edges of the FoV are not in good focus, but neither are they in real life when wearing eyeglass (like I do). That does not detract from the experience, because when you see motion in the corner of your eye you quickly rotate your head to bring the movement into the center of your FoV where you have overlapped stereoscopic convergence. In the "heat of battle", you do not notice any lack of focus around the edges...
geekmaster wrote:The perceived chromatic aberation is mainly blue (and mostly visible on text displays). In a 3D game it is rarely noticeable except when you look for it. And yes, you could adjust for it in software (as mention in the other thread).PasticheDonkey wrote:...
would maybe have to render a nose and brow etc. i think chromatic abrasion could be sorted in software as well.
Unlike your lens images, mine have the tops trimmed flat so the fit below my eyebrows so I can get them very close to my eyes. They must be very close to fill the entire FoV even with extreme eye rotation. In my case, I am near sighted so it is all in focus even with complete FoV coverage. Pulling the lenses away from the eye even a small amount reduces the FoV coverage quite a bit. If my focus does not work for you, you may need to add another lens element to the stack.
Stangely, after using this for larger than normal FoV, taking this off makes me very aware of natural vision occlusions such as my nose, eyebrows and cheeks (but especially my eyeglass frames and unfocused FoV outside them). Normal vision feels restriced and limited after such a "supernatural" FoV experience.
geekmaster wrote:Moving the screen away brings the screen edges into your FoV. Better to increase magnification and lose a few pixels around the edges than to bring unnatural occlusions into the picture.PasticheDonkey wrote:in that case moving the screen rather than lenses could adjust focus.
As it is, the edges of the FoV are not in good focus, but neither are they in real life when wearing eyeglass (like I do). That does not detract from the experience, because when you see motion in the corner of your eye you quickly rotate your head to bring the movement into the center of your FoV where you have overlapped stereoscopic convergence. In the "heat of battle", you do not notice any lack of focus around the edges...
geekmaster wrote:My screen center is not blurry at all. I can see individual pixels. It is the screen edges that blur, but even so it is much better to have blurred VR content at the visual boundaries than just a blackened shroud.PasticheDonkey wrote:well if the screen size was set so people with whatever vision required it further away could see the whole screen, then others could get focus moving it closer but would lose a bit of res.
how blurry are we talking at the centre of vision with an eye turned to full extreme? anyway this is a problem with all versions thus far.
geekmaster wrote:Yes, glass or acrylic aspherics would be better, but for a really inexpensive experiment, fresnels are good enough to give a feeling of immersion. And the pixels in the center area of of the screen were in sharp focus for me. Although the outer edges were stretched and blurred somewhat, they still added greatly to a sense of immersion, and when adjust "just right" I could read the part of the text visible at the right edge of the "Rift-warped" L4D YouTube video.KBK wrote:The contrast and resolution junkie in me says that single lens solutions will always be better looking than any set of stacked Fresnels.
That in stack of Fresnels, the air must be there, in order to produce the desired optical effects, and this stacking alone can ruin the CR and definition. The best case scenario is a around an overall what, 5% reduction in both CR and definition, which would look worse than the raw numbers would suggest.
A custom cut single lens is still the best bet, in my offhand analysis.
The single lens is a big advantage, when it comes to a custom cut, for the purposes of enabling eye movement. Regular optics, such as camera/projection and the like, make it so the cut has to be a specific type, but the singular interface of the HMD display and the lens make it so the DUT or lens/HMD display combo, in conjunction with the eye, can make a second cut work. and the second cut, is the one that allows for eye motion.
Glasses for human use are an example of a single cut. that cut staked with that of an aspherical as a secondary or paired concern, may be possible. But I admit I am weak on this particular subject. I suspect that the more expensive HMD's use something similar. However, eye/lens relational positioning then becomes critical. Messy subject, at best.
My idea was to make a simple cardboard frame with cheap dollar store lenses, similar to the one that came with my old VR Creations book, which could be attached to a tablet computer such as my Nexus 7. I published this because my experiment yielded results far better than past experiments using coarser fresnel lenses, and with lenses trimmed to fit snugly against the side of my nose and under my eyebrow ridge, the FoV exceeded what I see naturally.
Agreeing that non-fresnel lenses would be superior, I would like to duplicate this experiment with solid custom lenses that include outer offsets of 6-inch lenses, just like these fresnel magnifiers. These fresnel stacks may not be good for watching movies, but they are adequate for VR. But then my eyes are not so fussy as I get older. I used to clean my eyeglasses many times per day, but now I just adjust my head to look around the grime. I think that started when I got some scratches in my glasses and never bothered to replace them. Perhaps the blur at the edges that I do not even notice may annoy others who still clean their glasses often...
As you get older, available time becomes more precious, and expedient (quick and dirty) solutions are often more than acceptable. When younger, I was a perfectionist and needed everything scrupulously spotless. But that is not important any more. Just getting stuff done while I still can is most important to me.
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I am interested to see the opinions of others who try fresnel lens stacks...
geekmaster wrote:A future Rift with "supernatural FoV" would need custom lenses. The fresnel stack is just a prototype. I need to build an HMD with them so I do not need to hold my tablet PC and lenses with my hands. The real key is for the lens edges to actually touch the side of the nose, and the cheek below, and the eyebrow ridge above. That lets you see beyond your facial obstructions. And the offset portion from the edges of a 6-inch lens bends the 7-inch display to fill your full FoV.Zoide wrote:... I think your contributions here have been very valuable, and I hope to see your superhuman FoV ideas in the consumer Rift!
geekmaster wrote:With my fresnel lens stack, I have think I am getting 150 degrees horizontal FoV (including seeing video where the nose should be. I do not think it necessary to render a virtual nose occlusion. In fact, my nose distracts from immersion in the real world after taking OFF my VR viewer. Small critical details near the edges would not be good, but even blurred motion there is a huge help for immersion. After this experience, I think that including an "ambilight" for peripheral vision beyond the FoV in the Rift would aid immersion. Unless you are emulating an HMD/HUD, there should be no text or indicators fixed time the screen. They should be on a virtual vehicle dashboard, or HUD on the windshield, or on your avatar wristwatch, IMHO.
To maintain the best immersion, we must remember to emulate reality even for our status displays.
EDIT: I just did a little experiment that made me change my opinion about fixed text or status indicators on the display. On my Nexus 7 (with IPS display), I scrolled some text (web page here) by holding my finger still and sliding my tablet, to simulate head tracking. The text got blurry while it was fixed on my FoV but the pixels were moving under it. So small text would require getting your avatar close to it to make it readable. Until we get 4K displays and faster pixel switching time, we may still need status info locked to the screen, but I think that should be avoided if possible. Fixed text is fine for config menus though...
geekmaster wrote:I took some pictures, but I really want to do more experimentation. After cutting another lens stack to fit closer against my nose and eyebrow ridge above, it sacrificed too much peripheral vision at the edge.TheLookingGlass wrote:I can't wait to try your experiment with the fresnels when I get some time this week. I had read some great things about using fresnel lens for Monocular HMDs but haven't seen anyone stack them for a greater FOV. Have you taking any pictures yet of your setup? Or you are holding off until you have experimented more?
I also need to make a pair of them, and mount them in some sort of a frame. Because of their symmetry (both left and right offset edges), they should work fine for stereoscopic vision, but it needs testing...
I do not wish to post my CRUDE experimental photos just yet. They proved the concept to me, but after less than satisfactory results after cutting the second lens stack, I want to take more careful measurements so that my experiments are easily reproduceable.
After cutting the lenses into thirds, you just need to take the corners off to fit it closer against the nose and inner eyebrow ridge. As close to the eye as possible gives the widest possible FoV.
geekmaster wrote:Done! I just created a new thread:budda wrote:Hi,
Interesting work geekmaster on using fresnel lenses to achieve a super wide field of view.
My ideas above refer to a basic concept (which others have probably thought of too), but you have moved on with a practical realisation.
Post away, but I would have thought a more general thread for your work, such as "Fresnel lens stack for superior field of view" would cover both the fresnel lens approach and its other possibilities.
Thanks.
Fresnel lens stack for "supernatural" FoV
http://www.mtbs3d.com/phpBB/viewtopic.php?f=140&t=16373
It contains large quotes taken from my posts on this topic, scattered through four different threads, plus some PMs.
It makes more sense to follow this information in a single thread.