Anyone considered using a fresnel lens/ mirror system?

[shardian]

I tried searching on this, but couldn't find much useful info. Has anyone considered using a fresnel lens and a 45 degree mirror to simulate a larger monitor like in Virtua Cop? You can get a fresnel lens that fits a 19" monitor for $28 at www.3dlens.com .

Feel free to shoot me down if need be.

[ChadTower]

I've thought about it... conceptually, at least.  It can be done.  The sitdown version of Roadblasters does it really well, it more than doubles the "size" of the viewing area.

I think the biggest challenge would be lining it up focally in a standup cab.  It would have to be further away than a standup could easily handle without doing something like using a mirror as you've said.

[NickG]

Nice fresnels link!  I'm trying to use a small lcd and build some optics for it so that it may be stretched out the size of a marquee.  I will probably have to build my own anamorphic  lens but I might be able to just angle a couple of fresnels or parallel lenticules.   I may also employ a polarizing lens at the front.  Anyway, have you been to  diyaudio?  There are some people there making their own DIY rear projection systems.  Good info.

[spystyle]

That is a lot of big words!

[shardian]

I was a vet of www.diyprojectorcompany.com before it closed its doors and sold out to lumenlab. I don't care for lumenlab, so I gave up the diy projector stuff. Yeah, diyaudio has alot of very good  diy projector info, but is more of a reference now than a forum.

FYI, I'm guessing you meant a FRONT projector instead of rear. A diy rear projection tv is a total waste of time in my opinion. The results are sub-par at best, and you'll have more in it than you would buying a used commerical one.

[NickG]

I indeed meant rear projection. 
Rear- Projection TV: All-in-one display consisting of a translucent screen with a rear projector system.
^^That could fit in an upright cab
Front Projection: A system where the projector sits in front of the screen with the image getting reflected back to the audience.
^^That would not as easily fit.
P.S. sorry I couldn't be of further help.

[Kremmit]

The sitdown version of Roadblasters does it really well, it more than doubles the "size" of the viewing area.

The M.A.C.H. 3 cockpits used a fresnel setup too, FWIW.

[ChadTower]

I have always been tempted to walk up to a Star Wars cockpit with a fresnel... just to see if it works as well.  Probably would not with pure vectors.

[DarkBubble]

The sitdown version of Roadblasters does it really well, it more than doubles the "size" of the viewing area.

The M.A.C.H. 3 cockpits used a fresnel setup too, FWIW.

I could have sworn that Starblade did as well, but I haven't seen one since the early 90s.  Klov has it listed as using a curved mirror only, but I thought there was more to the image than a curve.  Good thing the mirrored plexiglass I have isn't wide enough, because I'd probably be trying to figure out how to accomplish it with my copy of Starblade Alpha.

I was a vet of www.diyprojectorcompany.com before it closed its doors and sold out to lumenlab. I don't care for lumenlab, so I gave up the diy projector stuff. Yeah, diyaudio has alot of very good  diy projector info, but is more of a reference now than a forum.

Checked out lumenlab and liked that idea a lot more than the old 13" TV/mirror/fresnel box.  Are the results really as good as it seems from the vids?  Shelling out $1000+ for a projector isn't something I'm comfortable with.

[shardian]

I've seen some peoples setups using 17" High definition lcd's that are pretty dang impressive. The higher end/ better quality build pj's using high resolution pc monitors are very nice too. I personally opted for the smaller, cheaper projectors. Mine (although indefinitely on hold for more important matters...plus the fact I have a commercial one right now) utilizes a psone lcd. My bulb will last roughly 10,000 hours, and costs $20 to replace. Resolution isn't great, but good enough for a rec. room definitely. I have roughly $100 invested in it.

There are three main benefits to a diy lcd projector
1. Long Bulb life.
2. Cheap replacement bulbs
3. New addition of small scale (17") High definition lcd panels.


A commercial high def projector is still mucho bucks, so a high definition capable pj for $1000 is a deal. What scares me from the high end ones, is that is doesn't take much to create a $1000 brick. The lcd can be scratched or fried during the build...there went $200. I don't know about the rest of people, but I have a problem with throwing away $5, much less $200.

[Portnoy]

Hey, my first post!  I actually did this 13 years ago.  I ordered the lens through one of those "not sold in stores" catalogs.  It was meant to turn your 19" TV into a 25".   I actually built an upright cab to house my hacked up Atari Jaguar.  Aside from a slight haze it produced it was actually pretty cool.  I used a 13" TV with the picture reversed.  Once I figured out the distance and how big I could go before loosing focus I ended up with what appeared to be a 30" screen floating about a foot or so past the back of the cab.  It's been dismantled since. Now I just chase my 2 year old son around the house with the lens in front of my face and I already have a large noggin to begin with .  When I get time I actually plan on rebuilding the project from scratch cuz let me just say the original, although functional and got plenty of gameplay, was not pretty to look at.

P

[ChadTower]

Welcome to the forums!

I think when I get around to fixing my Star Wars I'm going to order up a fresnel to see how much distortion it gives the vectors.

[DarkBubble]

I personally opted for the smaller, cheaper projectors. Mine (although indefinitely on hold for more important matters...plus the fact I have a commercial one right now) utilizes a psone lcd. My bulb will last roughly 10,000 hours, and costs $20 to replace. Resolution isn't great, but good enough for a rec. room definitely. I have roughly $100 invested in it.

Given the way old PC equipment basically gets tossed out as people at work upgrade their workstations, I'm hoping that I inherit some LCDs in the near future.

Out of curiosity, have you done some sort of test to see what kind of picture you'll get out of the PS1 screen?  How large do you plan on blowing it up?

[ChadTower]

Working monitors don't usually get tossed.  They just get sent to someone else in the company lower on the technical ladder.

[DarkBubble]

Working monitors don't usually get tossed.  They just get sent to someone else in the company lower on the technical ladder.

You'd think so, but it's a regular game of Keepin' Up With The Joneses around here.  When one person gets a new setup, someone sees it and wants a new one, and so on and so forth.  They bring everything but upgrades in through Dell, who doesn't like to knock much off the price for refusing a monitor as part of the package.  So, we end up with extra monitors on top of all of the old stock that's being decommissioned.  After enough of them build up and somone nearly breaks their neck tripping over them or they decide they need extra space, they say "I need these gone.  I don't care what you do with them, just make them dissappear."  I'll run it by the IT guy most times, but I've learned he doesn't care once he's gotten his pick.  Thus far, I've acquired some 17" and 19" CRTs, some working PCs, and various other parts.  Judging by the LCDs they've got laying around and the fact that a few people are talking new workstations from time to time, I don't think it'll be much longer.

[shardian]

I personally opted for the smaller, cheaper projectors. Mine (although indefinitely on hold for more important matters...plus the fact I have a commercial one right now) utilizes a psone lcd. My bulb will last roughly 10,000 hours, and costs $20 to replace. Resolution isn't great, but good enough for a rec. room definitely. I have roughly $100 invested in it.

Given the way old PC equipment basically gets tossed out as people at work upgrade their workstations, I'm hoping that I inherit some LCDs in the near future.

Out of curiosity, have you done some sort of test to see what kind of picture you'll get out of the PS1 screen?  How large do you plan on blowing it up?

Yeah, I have. I made a test setup long ago to see the image. I popped in a vhs copy of star wars, and I was very pleased, even with the lower quality bulb and optics I tested with. You can go up to 60" with a psone. It is equivalent in image quality to an older style rear projection tv. I guess I'll have to post something here about it when I do get it done...that is if I EVER get finished with my bathroom project...

[Kremmit]

Working monitors don't usually get tossed.  They just get sent to someone else in the company lower on the technical ladder.

Tell that to the guys at the SlaveNation Army thrift store.  The one here actually pays somebody to haul away the pile of them they build up every so often. 

As everybody goes LCD, there's a huge surplus of used CRTs.

[ChadTower]

I was talking about corporate culture/IS practices. 

Not Salvation Army thrift stores.

[Grasshopper]

I wonder whether anyone sells fresnel lenses that only magnify in the horizontal plane. Could be useful for building a Darius machine using only a single monitor.

[ChadTower]

I'm having trouble visualizing what you mean.  They magnify based on the point of view of the viewer...

[Grasshopper]

Darius machines had three monitors lined up horizontally to form a single image. One of the monitor images was actually reflected off a mirror (a bit like Space Invaders) to enable the three images to be stitched together with no gaps showing.

http://www.klov.com/game_detail.php?game_id=7514&letter=D

I was thinking you could build a MAME based Darius machine that only used a single monitor. The game would be shown on the monitor with the image squashed up horizontally. A fresnel lens could then be used to expand the image horizontally so that it looked like you were seeing three monitors.

[ChadTower]

I have no idea why they would design the original that way.

[Grasshopper]

I have no idea why they would design the original that way.

I've actually seen one in an arcade and the design works really well. In a nutshell you get a lot more screen area to play with.

[ChadTower]

Oh, I mean, I understand what it's doing, but there are other less failure prone methods they could have used to get the same thing.  Keeping one monitor going is hard after a while... but three?  And then if they get out of alignment it's all messed up.

[Grasshopper]

Oh, I mean, I understand what it's doing, but there are other less failure prone methods they could have used to get the same thing.  Keeping one monitor going is hard after a while... but three?  And then if they get out of alignment it's all messed up.

I guess the economics were different then. 20 years ago large CRT monitors were prohibitively expensive (ironically these days you can hardly give them away). That being said I wonder why they didn't go the Fresnel route instead.

[ChadTower]

There has to be another reason.  Perhaps separate CPUs feeding each display, giving a sort of three level parallel processor.  I don't know that around that time three 13" monitors was all that much cheaper than one 25 or 29.

[Kremmit]

There has to be another reason.  Perhaps separate CPUs feeding each display, giving a sort of three level parallel processor.  I don't know that around that time three 13" monitors was all that much cheaper than one 25 or 29.

Three 13 inchers makes for a playfield around 32 inches wide, 35-ish diagonal. If they'd acutally gotten one really big screen, they would have just been putting a standard 4:3 ratio shooter on an insanely huge monitor.  Instead, they created a unique 12:3 shooter, and the gameplay is different because of that aspect ratio.  I supposed they could have bought that screen and then wasted most of it's space on letterboxing the image if they wanted to create a super-wide shooter, but I don't think that's likely.  And then there's the resolution- unless they not only blew big $$ on a giant screen, but then tons and tons more on getting a super-high res (1986, remember) one, you're gonna have some seriously blocky looking pixels at standard res on a 35 incher.  Same applies to the fresnel route- the graphics would have sucked.

[ChadTower]

Oh wait... mounted horizontally but only slightly overlapping... I was picturing it differently.  I get it now.

[Kremmit]