So I'm building a table for /tg/ shit, and I want to put a projector inside to project whatever I need to show onto the table's surface. Then, of course, i'd put a layer of clear material over that to protect the projection surface.
The question is, what kind of material is best suited for this sort of projection? Is plexiglass or plastic better for protective covering? Would the projector take too much space?
That's actually a pretty dank idea. You would need to shell out quite a bit for a decent projector tho, and especially important will be finding one that will focus at such a short distance (ie floor to surface of table). Plexiglass might be a good protective surface, but you'll need something semi-opaque for the projection to show up on, like a white sheet of some kind.
A (perhaps cheaper) alternative would be to put a big flatscreen into the table, but both have challanges
I'd probably use a 4:3 flatpanel bolted under plexiglass in a way that it won't be load-bearing as to protect the screen itself. Any projector that can focus in that short of a distance is gonna set you back quite a bit.
I actually work with projectors and surfaces on a daily basis, and I believe you could use anything white to project on as long as the room is dark enough. The covering for it would be best if it were very clean glass, but reflections are going to suck. You'd be better off just using a durable white surface that has a low-gloss finish. Maybe particle board of some type. If your ceiling is not at least 6 to 8 feet away then you may have trouble getting it to be a big enough image. But if it's closer then it will look better, so do some research on that matter and worry less about the table.
In my somewhat limited experience projectors are expensive and for the money unreliable.
Get a it ass second hand TV, and put it in a frame, slap a peace of clear acrylic over it, and sand blast a grid on it. Run an HDMI cable to a laptop or something. Much easier than fucking about with projectors and mounting and shadows from figurines and players. And big ass TVs are roughly in the same price range as any decent projector, and have a longer live span. Projector bulbs go bad really quick it they are on for long periods of time. like 1000ish hours at best.
But if your heart is set on using a projector just don't use a glossy surface as the screen. Get a peace of white fabric. Best thing I found was painting cloth. It's like 5$ per 2m^2, it's white enough and will last a long time while looking professional.
best would be an actual fresnel (front screen of ole projection TV, or similar) - its what theyre for.
HOWEVA, what >>926110 said, you need a certain distance from surface to projecter lens, shorter the distance, smaller the screen - it depends on table size, or height mostly - check this works before you start building anything.
Id actually 2nd just using a screen - bonus points for touch - the (original) MS Surface was exactly this, huge ass table touchscreen, random link:
Modern LED or laser projectors don't use bulbs and OP could easily fit a short-throw pico/pocket projector into the bottom of a table, with some adhesive rear-projection screen material stuck to a glass tabletop.
Not sure the end result would be worth the trouble though.
> LED are immortal and therefore don't have a 1000h life span.
>They actually do
Exactly, it's not a bulb like a lightbulb. But for the not live breath eat electronics everyday /tg/ nerd, yeah, we'll just call the LED array a projector bulb...
Op could just pickup a craigslist rear projection tv for nothing and repair it or hack a better projector into it
You can also make an infrared reflection based multipoint interface with a free driver, a camera and an array of Infrared leds.
No shadows or reflections. The projector is under the table and you play on the screen. (or a piece of plexi on top of it)
What's your projector layout going to be? It sounds like inside the table, pointing up? What surface are you projecting onto?
If so, both types of plastic are crap. They scratch easily and they weight carrying capacity is limited - unless you get it pretty thick, or have a very small table. My suggestion is to get some tempered glass - an $80 coffee table from Ikea can be repurposed, or you can get some cut to fit for a bit more - that'll be as strong as you can get and almost scratch proof.
Set that as the table surface, frame it as needed, then frost it. Spray on frosted glass from any hardware store will do. That'll make your table top into an upside down rear screen projection surface. Project what you want onto the bottom, and you'll see it on the front. You could even project your game grid and forget about paper maps forever.
The trick will be spraying the frost evenly (practice on something else) and finding a projector with a short enough focal length to work from inside a table.
This was my initial plan.
Tell me more about this frosted glass.
You will not get a projector with as wide projection and short focus as you need for this to work. Your only solution is flatscreen or top-down projection which will suck because shadows.
Yes. I believe something like Eyenfinity technolgy from AMD could work automagically but you would need a graphics card with as many DPs as you have projectors. Even low-end FirePro graphics have 4 of them. Ive never done this so you have to research it more.
>Not even using a prism
- wutf 'prism' be used here, you retard? Thata a bog-standard 'big screen* projection tv setup - as OP was told to repeatedly use anyway. The projector is bouncing the image off a mirror to increase throw length, otherwise, image be too small, as it obv. is in his setup anway.
You then have an inverted image, which can be corrected by the 'flip image' command in the menu of every fucking projecter made in the last 20 years or so - for rear-screen projection setups.
As said, he wants a bigger image? he needs either a higher table, to extend the throw length with a mirror, or, use more projectors. End of the day, you are either re-inventing the projection TV on its arse, or the videowall, if you use multiples thereof. This 'using minature projectors automagically bypasses the laws of optics and throw distance' p!sh - wire in, but that theory is, and remains, somewhat flawed, just to save you the time, cost and effort.
tldr: drill a hole in the floor of your mothers basement, mount the projector in your secret sub-basement shipping container to gain enough throw distance (& thus, image size) - you good. Otherwise, lot of fucking around, mirrors, multiple projectors, etc. - or simply use a screen, as recommended.
The glass idea is just to make it semi-opaque so you can project onto it. It would work like any rear projection material, as long as you can apply it evenly. You want the white frosty kind, not the semi-transparent icy kind. Then you don't need two surfaces, cause the outer surface will be a tabletop anyway.
For getting the glass, I mentioned Ikea cause last time I was there I saw a glass table set for like 80 bucs. It even came with chairs. Repurpose the table top, give the cheap ass chairs to your gaming buddies while you sit on your skeletal throne.
No ideas about the wide focus projector though.
>The glass idea
buttermilk (ordinary glass - paint/better, airbrush on, let dry, done) actually works OK as projection surface as well (no, srsly) - dunno how long it would last (used to use it for temp projections), may need renewed once in a while, but it costs like $1 a gallon. HoloPro material is fantastic, but costs (slightly) more.
going back to the mirror thing, if you could leave one side of the table of the open? - no law that says projector must actually be mounted in the table. projector can then be enough distance away. still needs a (then, even bigger) mirror under the table tho, and someones always gonna walk in front of it ocassionally, depends on your setup.
>You will not get a projector with as wide projection and short focu
They're called "short throw" projectors
He might not get as big a table as he wants without shelling out huge bucks, but they exist
>"short throw" projectors
http://www.sony.com/electronics/projectors-4k/lspx-w1s - that one nice @ $50k - order it, they may even try building one.. The 'cheap' ones, you lose a lot of edge/corner detail - would all be easier, if OP provided a budget, and table size.