Slashdot is powered by your submissions, so send in your scoop

 


Forgot your password?
Close
typodupeerror
×
Hardware

Turn Your 15" Monitor Into 30 Cheap 142

Posted by CmdrTaco from the something-to-play-with dept.
John Reder writes "Here is a way to get the most out of your PC's monitor for a few bucks. This link will take you to a page that will show you how to build a Fresnel Lens Box with common easy to find items. A Fresnel Lens Box will double the size of your screen making playing things like 3D first person shooters more enjoyable!" Lots cheaper than a new monitor. Wonder what the image quality is like tho. An amusing hack if nothing else.
This discussion has been archived. No new comments can be posted.

Turn Your 15" Monitor Into 30 Cheap More

Turn Your 15" Monitor Into 30 Cheap

Comments Filter:
  • ... on some older arcade games ( can't remember which ones).
    ^. .^
    ( @ )
    ^. .^

  • I've done this.. (Score:3)

    by Cuthalion ( 65550 ) on Wednesday September 29, 1999 @09:56AM (#1649926) Homepage
    I've done just this - putting a letter-sized fresnel lens its focal length away from the monitor (for the lens I had, that was ~8 inches). I was able to project the image on to sheets hung across the room. It was kind of neat - I watched some display hacks on my ceiling.

    * The image was backwards. This could be fixed in software, but instead I got a mirror and started projecting onto the ceiling.

    * The brightness was low. Two reasons: If you make the picture twice as big, it's half as bright (assuming every single photon makes it to the right place). If you're projecting it, you need to be fairly far away to watch it without blocking the light. Secondly, not all of the light coming out of a monitor goes straight out. The bigger the lens, the more light you get...

    * Fresnel lenses approximate real lenses. And for an infinately far away source (frying bugs with the sun) they work really good. However, as the angle of the light hitting the lens increases (you get farther from the center) the quality of this approximation decreases (since you're not necessarily hitting the lens part, but will now send light through the ridges). Thus the image was fuzzy around the edges (I assume that's why).

    This would work a bunch better with a real lens, except that large lenses are hard to make and heavy and expensive. You could do it with a small lens, but it would be EXTREMELY dim.

    Despite all these problems my fool roommate still has a setup like this in the basement. But this is the same guy who spent ~40 hours (and ruined one of my drill bits) rebuilding a crappy $10 avacado-green sofa he took apart months before.

    -me
  • Yeah, but what about using it on an LCD monitor? I remember reading a few months ago about a new type of LCD monitor where the colors are layered on top of each other rather than being placed side by side. It seems like these types of monitors would work better with Frensel lenses in that they wouldn't unevenly magnify individual colors as you have described. Now which LCD monitors actually layer the colors like this is a different story. I can tell that my laptop puts the colors side by side, but I'm having a really hard time telling if my Apple StudioDisplay does or not (I think it does).
  • Definately get the Criterion set. The 'Love Conquers All' version is truly an eye-opener as to how editing can alter a movie.
  • I remember paying nearly $300 for the VictorMaxx "VR" HMD. I was in college then, I got situated in my hammock and put on the HMD expecting to get dizzy while playing flight unlimited. It was a disappointment to say the least I felt like I was looking at a Sega Game Gear at the end of a shoebox. I took that SOB back a few days later.

    LK
  • Yeah, i remember that. It was funny watching the caption at the bottom of the screen read "Redmond, WA", when they were filming in Bellevue Square in Bellevue. The operator had on a pair of what looked like safety goggles with a small display toward the bottom of one lens. I don't know if the stoned look was part of the presentation or the guy couldn't walk and read a the same time.
  • I got my one foot square fresnel lens as surplus
    from Edmund Scientific for under ten bucks some
    years back. It is indeed a great toy. I've
    even soldered with it under sunlight, but admittedly it wasn't a very good soldering job.

    Div.
    But my grandest creation, as history will tell,
  • My dad told me that he remembered the screen
    on the television they had when he was a kid
    was 'soft'. He said you could touch it and
    it would make the picture wobble and wave for
    a while (Pepto-Bismol effect is my name for it).

    It must have been a water filled lens.

    BTW, does anyone know where I can get CRT coating spray? I can't find anyplace locally that carries it anymore, and I've a 1951 'Sargent' television
    that works, except the CRT coating is starting to
    fall off.

    Thanks.
  • I have to get about as close as advertised to my screen as it is because of my vision. I have to stop now and then but I don't get headaches often at about 6-8 inches.

    As for reading through a magnifying glass, I use an 8x and I can read through it 5-10 minutes without headaches. No more.

  • I was in Tokyo in July of this year, and those 60" personal screen glasses are readily available - NTSC, no problems with US TV compatability. If you ever get there make sure to visit Akihabara - a five-block-or-so area full of every kind of electronic thing you can imagine, from the latest consumer DVD to junk shops with dismantled Mac parts or old NeXT boxes. Sony and Olympus are the two brands I tried, all work reasonably well, but if you're the 1000th person that day to try them out it can be an icky experience, especially in a humid Tokyo summer. They have vinyl pads for the forehead :-( Sony I think have one model, Olympus have three.

    I could watch a movie quite happily with one of these - I was considering a portable DVD player with a wearable monitor for all the flying I have to do - but it's still not as good as a good 21" monitor for PC use. Apart from the clarity (will we ever see a "virtual" trinitron equivalent?) it is a little too heavy to wear for hours at a time.

    Also consider the problem of someone getting your attention. No problem if you have headphones on, they can wave. If your eyes are covered... do you want someone tapping on your shoulder while you're totally immersed in Evil Dead?

    Unfortunately there's still no substitute for large amounts of cash when it comes to viewing enjoyment.
  • You're not magnifying the screen with the lens, you're focusing the light coming out of it.

    Have you noticed that during a partial eclipse, all the pinholes of sunlight are crescent shaped? (makes shadows of trees real funky) This is the same deal - a pinhole only lets light pointing the right direction through, a lens makes all the light point the right direction (to be focused). Instead of all the light being crescent shaped, now it's shaped like arbitrary images.


  • my acid-freak freshman year roomate at 'Bama did this with his 19" viewsonic about three years ago. the lens came from a really old, really large overhead projector, and the hood he made from a u-haul wardrobe box(y'know, the telescoping kind?). Focal length was kinda tricky, as I remember, and brightness was _REALLY_ low, but image clarity was excellent. Kipp had rigged a fractint slideshow so that it was timed to a winamp playlist. effect of a 15 foot screen was impressive (at least while you were on the psychedelics)...
  • Since the article was slashdotted, I didn't read it and assumed they were talking about projection, rather than magnification. At least projection's a little cool. So that post is 40% off topic. So sue me.
  • Well not Quake, but we played Tekken 2, Gran Turismo, and all other 30 PSX games I have on a 20 foot diagonal screen using a Proxima projector.. Great fun..

    Actually the best part was when the cat tried repeatedly to attack the projected images.. Boing.. MEOW... Boing.. MEOW...

    Dumb cat..

  • Re:... (Score:5)

    by PD ( 9577 ) <slashdotlinux@pdrap.org> on Wednesday September 29, 1999 @10:09AM (#1649941) Homepage Journal
    Actually, what you propose would actually work.

    If you can get the sun in between the lens and the sidewalk, then I can believe that the pavement would indeed liquify. A millisecond later the pavement would vaporize. Just after that, the compounds would break apart into their constituent atoms. And then right after that, the hydrogens that used to be in the pavement would fuse into helium.

    It would be much safer to put the fresnel lens in between the sun and the pavement, in my opinion.

  • Aren't those the same lenses you can use to incinerate objects at 30 feet away by merely putting the sun between it, and the object in question?!......

    somebody had to say it, so here goes: if you've got two objects 30 feet apart, and the Sun in between, I'd be willing to bet something would be incinerated... ;-)

  • That's all....

  • I've done that, it's mighty cool. We had a permement setup that could run 2000x1400 or something large. Something about 10 feet, corner to corner.

    And of course we had two, one at each side of the classroom.

    In AT&T, the after hours quake players (mostly teches) would take over conference rooms and play across the WAN.

    It better then a monitor, it's just as fun to bring popcorn and watch.
  • You may be able to see a bigger screen, but it does nothing for resolution. I don't think that this will harm the large monitor industry any. Trinitron (and the like) still rule the stores!
    Brad Johnson
    Advisory Editor
  • To bad it will just magnify my 14inch .42 dot pitch up to a 30 inch with 4.44 dot pitch. :)

  • ... (Score:3)

    by Signal 11 ( 7608 ) on Wednesday September 29, 1999 @09:17AM (#1649947)
    Aren't those the same lenses you can use to incinerate objects at 30 feet away by merely putting the sun between it, and the object in question?!

    I know somebody that had a lens like that - he actually heated the pavement up so much that it kinda-sorta liquified. Of course, the lense was about 30" in diameter too...

    Anyway... you may want to keep your monitor away from direct sunlight if you use one of these, lest you burn a hole through the tube!!!

    --

  • I bet this would be even cooler on my 19".. I wonder just how big I can get the viewable area.. without it looking too silly...

  • Max Headroom/Brazil (Score:2)

    by Anonymous Coward

    As an added bonus, your computer looks like something out of Max Headroom or Brazil.

  • Brazil! (Score:1)

    by jonr ( 1130 )
    That was the first thing popped into my mind.
    (For those who don't know what I'm talking about, shame on you, go to your local video store and rent the movie!)

    Jón
  • Can anyone mirror this? I wouldn't mind doubling the size of all the monitors in my house, but I need to know how first.

  • Not too good. (Score:4)

    by Negadecimal ( 78403 ) on Wednesday September 29, 1999 @09:25AM (#1649952)
    Besides the whole contraption looking pretty ugly...

    Fresnel lenses features concentric rings of angled plastic. The problem is that at the edge of each ring, there must be a compensating drop in the plastic.

    Your RGB monitor still constructs pixels by putting red, green, and blue phosphor triads adjacent to each other. If a fresnel edge falls across these triads at an angle, you'll get uneven magnification of the given color (i.e. for a white background, you'll see red, green, and blue patterns at the fresnel edge). Put a drop of water on your screen -- same icky effect.

    Not too good.

  • Awesome. I was just looking for information on how to do this a couple days ago. High quality fresnel lenses from Edmund Scientific arnt really that cheap though.
  • If you build the Fresnel Lens Box, make sure your monitor has enough ventilation so that it doesn't overheat or you might be buying more than a Frenel lens.
    The page didn't say anything about overheating, so I assume it wasn't a problem for him, but remember -- they don't put those holes in the top of the case to save on plastic.

    My old (mumble) brand SVGA runs hot under any conditions...

  • for one, .42 is crappy anyway. And that'd be in the end just .84 dp.

    But your pixels would also be twice as big, so you won't notice it as much if you sit farther away. I do see the use with TV tuners, tho :D

  • fourteen into thirty? not! (Score:4)

    by technos ( 73414 ) on Wednesday September 29, 1999 @10:38AM (#1649958) Homepage Journal
    Granted, your viewable surface may now be 30 inches diagonal, but you're stuck with whatever resolution the monitor supports. Trust me, 640x480 doesn't look any better on a 21' monitor, only larger. If you really want to upsize cheaply and don't want to waste that that Fresnel lens, move the monitor closer. Same effect, even less money. Use the lens to do more constructive things; here's a few ideas you might try..
    Use the lens and a mirror to test your employers fire sprinklers.
    Slip the lens under the glass of your office copier. No one will able to figure out why their copies come out backwards and HUGE.
    Small animals and your fresnel. 'Nuf said.
    Read the fine print on your Microsoft end user license. The part about 'your soul' and 'eternal damnation' is especially interesting.
    Peel the paint of your pompous neighbors new BMW. Serves him right for making your 1982 Chrysler look bad.
    You can have hot coffee sans electricity.
    Use it to make eight foot high shadow puppets on your roommates wall at night. Sound effects are optional, depending on the scare level of the individual involved.

    Did I miss any good ones?

  • I have a friend who is 18 and has a projector and
    a Dreamcast hooked up to it. The projector is decent quality. He use to have a N64 and Computer
    hooked up to it. The image quality is unreal. Playing games on that thing high or on LSD is fucked up. Watching movies is also so much better. He just need to buy DSS.
  • All you would need to do is figure a way
    to use a typewriter as your keyboard.

    The world needs more pneumatic message tubes.

  • It's worse than your realize. (Score:1)

    by Anonymous Coward
    You are overlooking prismatic effects. Put a beam of white light through a prism, and you'll see a rainbow come out. Red and Blue light doesn't bend at the same angle.

    I have enough trouble with this between my glasses and 20" monitors. God help us with this monster.
  • WRONG.

    The pixels will be exactly .03 inches square.

  • Re:... (Score:1)

    by AndyL ( 89715 )
    Putting the Sun between the lens and an object 30 feet away? Yea. I'd say that'd incinerate the object. The lens too!
  • the problem with this is that your res will only be 1/4 of what it was per inch. So even though your monitor will be bigger you'll have to sit like 4 feet away to expirience the same res. Now if you happen to own a killer video card that's just dandy, because you can crank it up to like 5000X4000 and go pixel happy. But a 14 inch monitor probably can't work with that res. But if you have a 2meg mach64 like me, well then you get to suffer with pixels the size of fists.
    char *stupidsig = "this is my dumb sig";
  • Wrong. the pixels were the size of primordial fists, and I imagine the pixels on this sucker would be more like primordial chunks of uncooked, unkilled beef.
  • I've done this years ago with a commodore 64. Used the lens from an overhead projector. I can't follow the link now, so i don't know how they propose overcoming the problem where everything ends up upside down. I took the simple aproach and turned the commodore monitor upside down. Made the picture rightside-up, but the colors got skewed. No good for general computer usage, but great for games if the colors don't go wacky on you.

    --Sean
  • If it is a windows user, wouldn't they be a "cow orker"?


  • *sigh* You know what I meant everybody. Okay, get some cheap karma points off of me, I don't mind. :)

    --
  • unless he meant launching the lens into orbit, on the opposite side of the sun from the earth. I don't see how this would help you fry an object 30 feet away from you.
    ^. .^
    ( @ )
    ^. .^
  • Do some searching - I'm pretty sure there's a Linux version of Acidwarp somewhere. I think I saw it a few days ago when I was looking for such stuff for this box after seeing Geiss.

    God, I want Geiss for Linux...

  • -Laktar, a.k.a. Nick Rosen, laktar.dyndns.org


    If I Ever Became An Evil Overlord:
    25. No matter how well it would perform, I will never construct any sort of
    machinery which is completely indestructible except for one small and
    virtually inaccessible vulnerable spot.
    -- Peter's Evil Overlord List, http://www.eviloverlord.com/lists/overlord.html
  • thats exactly what happened. colors got worse the more inverted it got. It didn't really matter- the graphics in c64 games were dubious at best. i tweaked the 'tint' knob till it was about right and was happy to have the biggest pac-man game in the neighborhood.

    --Sean
  • whoa, that was the first thing i thought of when i read this.

    actually, there was a mention of a system like this that was then routed through a projector, making the side of the neighbors house next door the biggest screen on the block...
  • I'm absolutely sure there is; I never saw Acidwarp until I saw the svgalib version. It did a lot of palette-rotating, so an X version wouldn't work quite as well unless you were in 8-bit mode with a private palette.

  • Actually, I can think of a great application for this for people with no cash (students)

    While monitors are nice, high quality, and expensive picture boxes, well, they're small for the price. So what's the idea? Take a 15", 17" monitor, strap a removable one of these on and voila, instant TV!

    Especially cool for watching DVD's or TV with a tuner card (Video4Linux Baby!) And most ubergeeks have decent sound systems too, gotta play the MP3's loud, huh? =)

    So what does this add up to? For me, if I can make this work on my 17" monitor and be reversable, that's a 34" TV for the viewing pleasure of my dorm floor, with the Matrix on DVD.
  • I wonder if you could build multiple layers of fresnel boxes and expontentially increase the size of your monitor. Screw 30", set up a double box for your own 60" monster. Just sit back 15 or so feet, play a vcd, and you got your own mega blurry mini-theater!!!
  • I've done this before back when doom first came out. Walmart had some cheap 8 x 11 ones for 99 cents in the office section, but as you imagine the lens quality wasn't real great & the thrill didn't last long.
  • Except for, maybe, a novelty thing, this makes no sense. I wouldn't be able to stand sitting in front of a huge-pixeled blurry display for any length of time. There's really no comparison between a magnified 14" monitor and a 21" monitor (except, perhaps, in the number of headaches you'll get from the former.)

    Heck, 21" monitors aren't even *that* expensive anymore. I got my 21" Sony 520GS for $500.

    - A.P.
    --


    "One World, one Web, one Program" - Microsoft promotional ad

  • That's nothing compared to my father's old WWII six foot diameter parabolic searchlight mirror. Get it angled right at the sun and it'll ignite the end of a 2x4 instantly, or melt a solid chunk of iron.

    Too bad he lost it when he sold his old house... I'll have to buy another when I get an extra 2 - 15 thousand bucks.

  • At school we have a $3000+ projector thingy. It displays a computer screen on the wall (or whatever) very large and very crisp and clear, i mean you can read 8pt font on this thing, it's amazing...playing quake is a beauty

  • Well I don't remember Beyond 2000 _promising_ us anything (I do miss that show though) but there have been many products over the years that brought Head Mounted Displays (HMDs) to the consumer marketplace (I'm not even going to get into scientific/educational HMDs here).

    All of them have been plagued by motion sickness, dizyness, and eyestrain, not to mention, especially in the consumer marketplace, unrealistic expectations (chalk it up to hollywood and a populace ignorant of technology).

    I figure my eyes have gotten bad enough I'm hoping for the full on cyber replacements but that's an even more off topic post.

    Anyway, for the momment being my favorites are the Sony Glasstron's mentioned in the post above. Keep in mind there are two models, the Glasstron PLM-S700, which is capable of 800x600 resolution meant for computers, and the Glasstron PLM-A55, which does 800x225 and is meant for portable DVD playback personal widescreen style.

    Sony's Pages are:
    PLM-S700 PC Glasstron [sony.com]

    PLM-A55 [sony.com]: Silly bastards have them under camcorder accessories...

    An excellent source I found for these and other HMDs is Mindflux [mindflux.com.au] though keep in mind prices there are in Austrailian Dollars.

    And BTW, I remember a DOS program called Acidwarp that if you used a certain command line switch would dump out several pages of text intructions on how to build exactly this type of device for projecting it's visuals onto a wall.

    There is nothing new in the world, only new implementations of old ideas, and newbies discovering the same old shit.
  • Would running at higher resolution help combat some of the quality loss?

    Nope. Look at your monitor really closely, notice how small the pixels are. Now look at your tv, and notice how much bigger they are, and how much more space between them their is. Dot pitch is the space between pixels, in millimeters.
    Cheers,

    Rick Kirkland
  • is there something like cthuga, except as an xmms plugin? that would be very nice. i know winamp has something like this.
  • I read something like this about 10 years ago, someone had a trippy demo and used a fresnel lens in a similar arrangement as a *projector*, looked pretty good except that the image was upsidedown and back to front or something, which didn't matter for this particular demo but would for anything else....
  • That's what I had in mind, but I wasn't gonna say it ;)

  • Too bad you can only see if the screen is darker than average, or lighter than average :)
  • This may be a cheap hack, but you get what you pay for.
  • So now you can turn your monitor into a 30" monitor without increasing pitch, and you end up having to sit six feet from the monitor if you want to make out what's going on...

    Besides, seeing Windows boot up on such a large screen must be the stuff of nightmares. :)

    "There is no surer way to ruin a good discussion than to contaminate it with the facts."

  • I did this to turn a tiny portable TV into a 14" screen. Don't expect great image quality, as you are magnifying the monitor's defects and limitations, too. The viewing angle is very narrow. Maybe two (very friendly) people can watch the screen without seeing an edge get cut off. The circular pattern, extra glare, and extra blurriness can give some people a headache, too.
  • I think the focal length for these types of lenses might be just a little bit longer than the distance these are meant to be held away from the screen. :)
  • Unless you can pump your 15" monitor up to, say, 1600x1200, these might not do all that. You're also magnifying the dot pitch of the monitor itself, so you're going to get a noticable loss of quality.

    I have my 17" at home set at about 1280x1024 and my 21" at work set to 1600x1200. Things are about the same size either way, but I have lots more "area" at work.
  • You may be able to see a bigger screen, but it does nothing for resolution. I don't think that this will harm the large monitor industry any. Trinitron (and the like) still rule the stores!

    Would running at higher resolution help combat some of the quality loss? I tend to run things at ungodly high resolution (Desktop at 1600x1200, Quake2 at 1024x768) but I can always use a more immersive environment...

    Kintanon
  • "Sorry, babe, in order for you to see it too we need to squeeze closer together. Yah, just like that...."

  • This has been around for years.. (Score:4)

    by Prote O' Zoa ( 84397 ) on Wednesday September 29, 1999 @09:32AM (#1650017)
    ..and frankly, it's not a very good hack. The room has to be pitch black in order for you to be able to see an image, and the resolution is terrible. If you want a big projected image, you'll have to buy a real projector in order to get any worthwhile results.
  • What do you expect for $10, a perfect image equal to or better than a $1500 21" monitor? If it were that simple, would monitors that big actually cost a few grand?
  • Although this ideas sounds a little ridiculous for playing games and such, I once had instructions for a similar contraption that could be used as a projector in a dark room.

    Just add a nice psychedelic screen saver that can be triggered by your sound card and you can turn a $2000 computer into a nice little $100 "laser light show" device. :)

  • Re:... (Score:3)

    by Kintanon ( 65528 ) on Wednesday September 29, 1999 @09:36AM (#1650020) Homepage Journal

    Aren't those the same lenses you can use to incinerate objects at 30 feet away by merely putting the sun between it, and the object in question?!
    I know somebody that had a lens like that - he actually heated the pavement up so much that it kinda-sorta liquified. Of course, the lense was about 30" in diameter too...

    Anyway... you may want to keep your monitor away from direct sunlight if you use one of these, lest you burn a hole through the tube!!!

    Here is a link to someone who has done some fairly destructive things with a Fresnel.

    http://www-personal.umich.edu/~bclee/lens.html

    Kintanon
  • I found an old archive of a dos system and looked in my "standard" utils director. Of course acidwarp.exe was there. So I grabbed it and tried it out under linux.

    WINE actually ran it of all things in a direct draw window. SWEET! Of course, it is only in a 320x200 window, but I'm impressed it ran at all!

    Now, if I could only get timeless to work!
  • you can still buy these things made in a decent size for TV screens, they've been around since at least the mid-1960's. They don't cost very much. And if you have one that's big enough to cover the whole screen you won't get a sore neck from peeping through the little hole.

    Sheesh. The things some people do to save a coupla bucks.
    Consciousness is not what it thinks it is
    Thought exists only as an abstraction
  • I :::ahem::: borrowed a real new infocus projector and hooked it up to my N64, projected it onto a wall in my basement. Real nice if you are sitting rather far back, the image quality is outstanding on those InFocus projectors.

    Never got the chance to hook it up to my PC sadly, but GoldenEye, Rogue Squadron, Turok 2, EP1 Racer, all look great (that memory expansion pack really does help at that level hehe).

    As for Q2 I imagine that you would have to pump the resolution on it, therefore slowing the framerate, something VERY important at that size as well.

    Think about it - You've got a 7 foot tall screen ... it's fun. (Get it hooked up to a good sound system with either digital surround powered by a Live! card or just some prologic faking...). Immersion.

  • Actually if you wanted the best in 3D realism, you'd get those Wicked 3D LCD shutter glasses and a projection unit for 3D depth at "real-life" sizes.

    -Mister Boffo

  • Hey! Don't rear projection TVs use these things? That would explain why they're so terrible to look at from the sides...

  • what I want to know is, would the increased screen size really be worth having to sit so darned far away from the thing? like sitting up close to a small screen, which, if you're dealing with 15", 17", and 19" monitors isn't that small, so it is with sitting far away from a large screen. Plus, I've noted that many people have expressed concerns with this (though i don't have any ideas of my own concerning such matters).

    either way, if you're sitting farther away, you're that much farther away from the kcyboard/mouse (long cords, I realize), and the cpu (yes, you have to move disks around sometimes, you know)

    just my $0.02 worth
    • Which raises the question: Has anyone tried playing Q2 or something similar using one of the conference room style projectors, such as the ones made by In-Focus? I realize image quality would not be "outstanding", but would it be "acceptable"?
    At DefCon [defcon.org] 5 they had a Quake tournament (which I lost first round cause the keyboard I was using only allowed one key to be pressed at once, which really fucked up my game) where one of the guys was playing through a projector with probably about a 15 foot diagonal screen. It was really cool to watch but the room should have been darker (a projector that outputs more lumens would have made for a better image in a medium-light condition like that).
  • Does this remind anyone else of the Terry Gilliam movie "Brazil"? I mean, they had these 2" screens magnified to about 13".
  • Brazil just happens to be on ShowCase right now. For you americans, it's a station that plays a lot of foreign/domestic shows and films, mostly really good.

    This showing of Brazil came on right after Quadrophenia (nothing beats watching Sting kicking the crap out of cops).

    It's quite a coincidence this story came up when it did. The fresnel enhanced monitors in Brazil would definitely drive me nuts.

    Then again, lenses would be least of my troubles in that particular dystopia.
  • What the article does not mention very clearly, and what most people here seem to have missed, is that the Fresnel lens parallelizes the light beams from the screen, thereby giving "depth" to the picture.

    For this reason, Fresnel lenses have been used for ages amongst the flight simulator fans, as it greatly enhances the feeling of immersion. Instead of focusing 1 feet away on your screen, you can focus somewhere around 3-10 feet away. The size of the picture is secondary.
    It does get a bit blurry, but that's just a bonus in some cases.

    You wouldn't like to use this thing for editing text on a 1600*1200 resolution screen !

    /J

  • Actually a "regular" 30" lens will do exactly the same thing, but you'd probably not be able to lift such a thing. That's why the Fresnel lens was invented: you take a regular lens, cut it into concentric rings, then make all the rings equally thick and glue them back together (more or less).

  • Heh -- idea is not new (Score:3)

    by Kaa ( 21510 ) on Wednesday September 29, 1999 @09:37AM (#1650042) Homepage
    When the first TV sets came out (back in the 30s I think) their screens were really really small. To compensate for this, some TVs came with special lens which were like 15 inches in diameter and had to be filled with water (solid glass lens this size weights and costs too much). These lens were suspended in front of the TV screen and that's how you watched TV.

    Kaa
  • Yep, they were selling these contraptions for TV's out of the ads in the back of electronics magazines 20+ years ago. I can't imagine them being human tolerable with hi-res monitors.
  • 6.) Mount the Fresnel Lens Box on the front of your monitor so that the lens is positioned about 6 inches in front of your screen.
    [...snip...]
    You will notice that you will be placing your face really close to the lens and you may actually have to move your head to look up and down at the four corners of the screen.     I read this as:
    A: Eye strain from your eyes being too close to the monitor, and reading through a lens (glasses excluded, has anyone tried reading though a magnifying glass for a long period of time?).
    B: Neck aches/injury, from "mov[ing] your head to look up and down at the four corners of the screen" All in all, it sounds like a pretty painful way to get a blocky image.

    ---
    Stephen L. Palmer
    http://midearth.org
    Just another BOFH.

  • server == toast (Score:4)

    by drwiii ( 434 ) on Wednesday September 29, 1999 @09:39AM (#1650045) Homepage
    YAMS: Yet another mirror site [min.net]

    Still missing 2 images, hopefully they'll be up soon.

  • Another link (Score:4)

    by Kintanon ( 65528 ) on Wednesday September 29, 1999 @09:40AM (#1650046) Homepage Journal
    http://users.intercomm.com/ajones/fresnel/fresnel. htm

    Is another link, this one provides more links including where to buy high quality Fresnels.

    Kintanon
  • When I was a kid I saw something like this at Sears, or JC Penny or some other department store. But, they had a floor model 21" TV Mag'd up to something like 40". It was Kinda cool because it made the picture bigger for like $100 or something, but the down side was that it was like DSCAN LCD display. You had to be DIRECTLY in front of it to see the image clearly.

    I'd rather save my cheddar and my time to do some other worthwhile upgrade to my system.

    I'm still waiting for the eye glasses that simulate a 60" display that those bastards from Beyond 2000 promised us.

    LK
  • So does that mean I can display a JPG of the sun on the monitor and burn objects (people?) in front of the monitor?
  • The pixels will be the size of fists...

    Is that really a unit of measurement?

  • But your pixels would also be twice as big, so you won't notice it as much if you sit farther away.

    Actually 4 times as big. If you want them twice as big you need 1.4x magnification...
  • My mom's vision is getting worse, and a friend of hers offered her a TV-sized Fresnel magnifier.


    We didn't install it on the Macintosh (where the vision problems are more important) - there wasn't enough physical space on the desk to install the Fresnel and still sit in the chair with the keyboard on the desk and get reasonable viewing distance. Also, the Mac's screen wasn't bright enough, and the monitor keeps going semi-blue, so I set her screen fonts bigger, and printer fonts bigger, and eventually a new monitor will help.


    So we installed it on the TV. It's just a big curved Fresnel with some metal-rod hangers that you hang 6-12 inches in front of the TV screen. Works pretty well - you have to sit straight in front of the TV to see it, but the picture does get about 20-30% bigger for reasonable adjustments. It's still bright enough, and being a bit fuzzy around the edges is ok for TV, even though it would be really annoying for reading text. Vision's funny about things like that.

  • I wonder if you could build multiple layers of fresnel boxes and expontentially increase the size of your monitor.

    No need. Just get a single better fresnel lens that do all the magnification in one step. The quality loss from a single fresnel lens would be much worse with several of them too.
  • You know, back in the VGA days of DOS, there was a little graphics demo called acidwarp. It was a bunch of palette cycling, and pretty cool stuff for (at the time) a 286 in 320x200x256. Also, if you were to start it waith a certain flag it'd give you directions for 'the warper', which sounds exactly like what this is. Now this is a good application for it -- already cheesy resolution graphics and a situation where blurriness isn't a problem. I never got around to building one, though, due to a lack of a fresnel lens or a credit card to order one from Edmund Scientific.
  • I ran across this on EBay... http://www.100inchtv.com/ and was wondering if anyone has tried it... It's instructions on how to build a front projection TV. I am guessing that you'll loose nearly all your brightness in the magnification, but if it isn't too bad, would be kinda neat to put Rogue Squadron on my wall...
  • I wish. Actually, I have not had time to complete the website. If you are interested in purchasing something though, email me for a price quote. We are pretty damned cheap, are are legit unlike those pricewatch companies. Oh ya, we accept credit cards. :)

  • * The brightness was low. Two reasons: If you make the picture twice as big, it's half as bright (assuming every single photon makes it to the right place). If you're projecting it, you need to be fairly far away to watch it without blocking the light. Secondly, not all of the light coming out of a monitor goes straight out. The bigger the lens, the more light you get...

    Actualy if you double the image size you quarter the brightness. It follows the inverse square law.

    Just wanted to correct a fact.


  • OK, once I put the game idea and the projector idea together, I realized how cool it would be to play Q2 on a 9 foot screen. Problem with the fresnel box is that the image would be reversed left-to-right.

    Which raises the question: Has anyone tried playing Q2 or something similar using one of the conference room style projectors, such as the ones made by In-Focus? I realize image quality would not be "outstanding", but would it be "acceptable"?

    Yes, I am fully aware of how much of a geek one must be to come up with such a question. The scary part is that I'm perfectly comfortable with that. :)

  • Some tips... (Score:5)

    by Anonymous Coward on Wednesday September 29, 1999 @09:51AM (#1650062)
    Site is /.'ed, so this might be redundant...

    I've actually done this before (a long time ago). A mirror, a lens, a box, and an old monitor and voila! But it's not as K-RAD as you might expect.

    You lose A LOT of brightness from the expansion (imagine the brightness of a 14"er spread over a 6'x6' square!), from lens impurities (it's plasitc for christs-sake!), and from 'leakage'. This last one will KILL this project. If you try this, make SURE you enclose the box and paint it with matte black paint on the inside. Turn the brightness on your monitor up FULL-BLAST (BEWARE: I'm convinced this is what killed 1024x768 on my 14" throw-away). Also, close all your windows and shut off all the lights. Ambient light will force your pupils open and you won't be able to see the screen clearly.

    The lens was $3 (!) at the local surplus store. My brother tells me it can double as an asphalt melter, but I've never tried. :) A 12"x14" mirror was only a few bucks, too.

    I use this setup to have a CTHUGA box (486 w/ DOS, no flames, please) playing constantly in my living room. It's a very entertaining thing for me and my friends when it's all fired up, and with a program like Cthugha, the slight blurring kinda works to it's advantage. (if you've never seen/heard of Cthugha, you've missed the coolest thing I've even seen on a computer: http://www.afn.org/~cthugha [afn.org] )

    Not exactly perfect for games, but definitely a fun geek project for a weekend. If anyone has any questions, don't hesistate to email me.

    Bart "We don't need no stinkin' accounts" Grantham
    grant_b@cs.odu.edu [mailto]


    PS - Add MAME to the mix and rock on out with some Ms PacMan. Don't deny that is what computers are for!
  • I remember seeing these at Sears and Wards back in the 80's.
  • They used to sell big magnifying glasses for tv's back in like the 50's or so, not quite sure when. They also sold a magnifying glass to increase the viewing size on sega game gear. My brother had one on his gamegear, and just looking at games were very irritating and not the best quality, so we never used it. Heres a tip, forget it, don't waste a nice 15 inch monitor, your better off staring really close into your monitor, heh.
  • This seems a lot like the "warper", of acidwarp fame. There was a certain commandline option to the program which described a very similar box, except it was designed to be used as a projector. The setup worked surprisingly well when you shut off all external lights and cranked the brightness. Pretty swirly colors. Not bright enough for text or gaming, though.

Slashdot Top Deals

The 11 is for people with the pride of a 10 and the pocketbook of an 8. -- R.B. Greenberg [referring to PDPs?]

Close