View Full Version : Test of TripleHead2Go and 3 projectors

01-05-2007, 07:12 AM
I posted this over on the FDS forum after some discussion with the folks there. Pics and a video of my tests are here: http://www.insitesolutions.com.au/737project/design_visuals_testing.htm

Matt Olieman
01-05-2007, 10:37 AM
Yeah, that's quite impressive... after looking at that, it certainly got my wheels turning in my head.

Nic, are you getting about 120 degrees with that setup? With the prices of projectors coming down, you can get three for the price of one I paid for.

Thanks for sharing Nic :)

01-05-2007, 07:09 PM
Hi Matt - when the view is pulled back to 0.31 zoom I estimate a view range of about 130 - 140 degrees.

01-06-2007, 02:21 PM

Checked out the pictures and the video. Sure wish I could use projectors in my project. The turn gave you a good feel of motion.

Well done :D

01-07-2007, 03:00 AM
Looks great but one thing bothers me.

Please don't take this the wrong way but either your camera is amazing or the video was edited. There is NO WAY 3 pj's running and everything but the screen remains perfectly black! My one PJ emits enough light to make my 10x20 garage look like daytime! So either your camera is deceiving us by not showing the true picture or you have 3 pjs doing something scientifically impossible. :)

01-07-2007, 05:48 AM
Well it ain't the camera - that was shot on a tiny Canon digital camera (not even a handycam). And it wasn't the editing coz there was none - just an AVI imported into Windows MovieMaker and exported to WMV.

Keep in mind that the 3 projected images were not large (about 1m wide each) and tightly focussed. Altho - last week I used one projector on a whole wall (to watch a movie) and that didn't light up the room either.

I am yet to see the light-spill and washout from multiple projectors that others have referred to. Maybe these BenQ projectors have made something scientifically possible? :)

01-07-2007, 09:53 AM
Please explain to me how a light emitting device bouncing off a reflective material doesn't light up objects in the same room. If what you are saying is true, BenQ's would be the only pj's being bought. Sorry, i have seen them in person as well. ALL projectors throw excess light. There is NO WAY your room is staying jet black dark everywhere but the actual screen. Well i take that back, if the pj's are only 3' from a screen and mounted in the middle of a gym, maybe then, but i bet you still wouldn't need a flashlight to get around like what your video portrays. Take a look at my website showing my single pj set-up with th elamp in Low/Econo mode. Maybe i need more details about the room you are using the BQ's in. Light absorbing paint, furniture, oxygen. :))

01-07-2007, 09:56 AM
Trying to find the sight that shows 3 projectors in a sim room, the room looks like daytime all the time inside. There actually several sim pics out there with pj's ALL showing lots of reflected light.

Matt Olieman
01-07-2007, 11:01 AM
There is screen material that is darkened, but reflects light directly from the pj. It uses glass beeds or something like that.... VERY EXPENSIVE, light bounces back to (in our case) the cockpit. It supposedly 3X brighter then a plain white surface.

Last time I looked the material was around $8 USD a square foot.

01-07-2007, 12:37 PM
I think i know whats going on, I tried a pic with my camera focused only on the screen and it made it look artificially black around it. Probably because the screen is so bright. I bet if you took a pic from the side, we would see what i'm talking about. The ONLY way to eliminate this light bleeding/spreading, is to rear project from an enclosed area seperate from where the viewer is. It's simple physics, **** even your little TV lights up a room from total darkness, now throw the switch on 3pjs at 2500 lumens, YIKES. :)

01-07-2007, 05:36 PM
Yes I think its got something to do with the contrast that the samera sets up when taking the pic. However ... the 3 pj's did not light up the room like daylight. The lights were off, it was night, but with the 3 pj's running the light level was still reasonably low. Part of the reason may be that the screen was reflecting back onto fairly dark/complex surfaces (behind where the camera was) and the screen had a slight angle down so not much light was reflecting up to the white ceiling.

Sorry I can't ease you're pain on this... but there are no tricks or expensive stuff involved.

Hans Krohn
01-31-2007, 12:10 PM

there are different projectors out there. Those ment for videos (but also handle PC graphics) usually have much lower lumen output than projectors built for presentations. These are so bright they can even be used in a room lit by daylight.

I found that the most expensive, luxury type video projectors often output no more than 700 lumen!

That should be perfect for a 3 projectors setup (the 700 lumen, not the $$$ you need to spend for the high end stuff :-))


Paul Thomas
02-12-2007, 02:39 PM
I found this very impressive and it looked just great. Thank's a lot for the great info.

02-25-2007, 05:01 PM
That looks sweet! You could watch an inflight movie on the left screen while you keep track of whats goin on in the center and right screen on those long flights lol.

Hans Krohn
03-30-2007, 07:49 AM
Hi Matt - when the view is pulled back to 0.31 zoom I estimate a view range of about 130 - 140 degrees.

I measured it:
in FS9 at max zoom of 0.31 the field of view is exactly 109 degrees.


Matt Olieman
03-30-2007, 09:30 AM
Sounds about right Hans, thanks for the confirmation. Also sounds like 5 projectors to get 160 degrees.

Regarding type projectors, just my opinion... 700 lumens is not much, I'm finding most have medium range projectors having double that.

Also, what I would be looking for is the ability to manipulate the framing of the image, so it would line up with other projected images. That's what's going to make it expensive.

Any suggestions?

Hans Krohn
03-31-2007, 05:58 AM
Hi Matt,

for image manipulation a projector should have at least these two things:

- manual zoom
- electronic keystone correction

The first is useful (and most projectors have it) so that small placement errors of the projector can be corrected. Important for ceiling mounts, where you can't just keep drilling holes until you get it right :)

The latter in case several projectors need to be mounted close to each other (that will be my case). I will vertically stack them so the ventilation of one does not suck in the hot air from it's neighbour... That's were keystone correction comes in handy.

About the lumens: I finally went for Benq DPL presentation projectors that output 2200 lumens in Eco-Mode. That's a lot, but it means my room will not have to be completetly dark. It will not be dark anyway, with 3 projectors putting out so much light! The 700 lumen projectors I wrote about earlier are usually very high end home cinema projectors, often based on tubes, not DPL.

I will start putting my first thoughts on the issue (and some sketches) on my website shortly and I will post a link here.

Have a good weekend,

03-31-2007, 09:42 AM
Hi Hans & Matt,

I added a few pics to my site today (New Pics), which show my efforts with the 3 projector setup - first I would say thanks to Nic for his posts and ideas- I still do not havemy ideal setup, but so far it's far better than a desktop.

I think in my case the key will be a ceiling mount - this will give better alignment,and no vibration, but I am currently thinking of turning the whole sim thru 180 degrees to make better use if the space available.

My current setup is 3 screens of 1.5m across 3.6m of room width, with each image 1.5 wide by 1.1 high (m) - This gives 3.6m wide image, but with some distorsion due to the screen angles.

Really this is not noticeable in use, except when an AI aircraft passes across the join in the screens - in flight it is not noticable.

My ideal would be 5 projectors, but I currently do not have the space to do that - also the shell causes problems with shadows - currently in the lower corners, but with the side views, I could not get the distances correct due to the room height.

Hans Krohn
03-31-2007, 09:50 AM
Hi Paul,

do you have the screens angled?


03-31-2007, 04:40 PM

I added a sketch to show dimensions of my current setup.


However - limitations are : I am using the screens which came free (1.5x1.5m), and the full width of the room (3.3m).

The projectors are mounted on the shell, and so move with vibration, and are difficult to line up exactly, due to varying keystone and angles.

My original idea was a 3m flat screen running in front of the windshields, using back projection - this would eliminate any "external influence", by closing the views from the room. - I still need to find the right material for the screen, but my tests with sheet where promising.

Having said that, the current view is quite OK - you don't notice the angles from the seat, and the view on the ground is quite acceptable, where you have more visual clues - straight lines on taxy and runways. In the air there is no difference, and the views are good - the monitor side view is really good on turns on descent/ascent, where you get views of the scenery on the downward side.

The best test (as we always so self critical), was a friend came over yesterday to fly, and was blown away by the views - no complaints at all!

Let us know how you get on with your tests.

Hans Krohn
03-31-2007, 05:31 PM
Hi Paul,

you say: "varying keystone and angles". Does that mean different projectors?

I think that one big flat screen is not the solution, because for a focused image from 3 projectors we would ideally need a curved screen. In my case, I plan to use 3 screens that are close to a circle that has the pilot in the center. Easier for me than for you, because I have a single seater cockpit. I do not have to worry about how the copilot perceives things...

Now it's late here, but tomorrow I will upload a sketch I made of how I plan to do my setup, based on the max. FOV obtainable in FS9 at a max. zoom setting of 0.31 (= 109 deg.)


04-01-2007, 04:07 AM
I think you are probably right, Hans - I have 3 identical projectors, but they are mounted at different heights, as I am still testing to achieve the best result.

The centre one is on top of the shell, and the outer two are lower, on the side view boxes - my plan is ceiling mount all 3, whch will eliminate the problems I now have on lining up the images.

The width of the shell, and the centre post and screen wipers also get in the way, and cause a shadow on the outer lower edges of the image - this too will be eliminated I hope.

Over Easter I will get some wider screens, and reset it up again.

Hans Krohn
04-02-2007, 04:52 AM
Hi Paul and Matt,

as promised, here are two links to early sketches of how my projector setup will look. I will have exactly the same FOV in FS9 and physically in my setup (i.e. 109 degrees), so I hope it will feel credible.

Here are the links:


My projectors will be 3 x Benq 721c

All the best,

As you can see, the projection center lines of all three projectors intersect exactly in the Somatosensory Area (i.e. right behind the Parietal Lobe) of the pilots brain - that is the area where flightsim related information is processed - thus creating the uncanny feeling of the image being "as real as it gets"!

Matt Olieman
04-02-2007, 09:23 AM
Similar to my planned setup.

I've got the screen (160 degrees curved), only had one projector because lack of room.

Once in my new location I'll have the similar setup, but curved screen. This will present a little different problem because it's curved. I need to be able to curve the projected image on each projector.

Hans Krohn
04-02-2007, 10:36 AM

that can be done, but it requires special lenses. As far as I know, these are availabe for the high end projectors only, and at a high end price... :-(

Let me know what solution you find (maybe custom made optics in front of the regular lens?)


Bob Reed
04-02-2007, 10:38 AM
Hey Hans.. Matt is playing with using mirrors to bend the picture. Seems to work pretty well!

04-02-2007, 12:47 PM
Thanks, Hans,

That looks like exactly what I am doing as well - dimensions are similar (ps you have a 0 missing on the dimensions)

I will also try and get a better curve/join on the screens.

I never thought about having the centre of the projectors behind my brain - do you think that will make a difference?
Anything to ease the workload on my poor overworked abilities!

Maybe I'll give it a try at the weekend..:D

Hans Krohn
04-03-2007, 03:31 AM

I was kidding...
To make the projection THROUGH the pilots prain work, you would obviously have to drill a hole through his scull. A rather unpleasant procedure, to be sure. Besides, for perfect image quality the pilot would have to sit perfectly still - no wiggling in the seat during those long CRZ portions of the flight...


04-03-2007, 06:14 AM
Me too - :D

After all, it was April 1 !

04-17-2007, 07:00 AM
Made some progress over the weekend on new screens and projector mounts.

I made a lattice "scaffold" out of alu box sections, and mounted the 3 projectors upside down above the cockpit - this means I can adjust the location of each projector without having to drill holes in the ceiling.

New screens out of 3mm MDF, and painted white. On setting everything up, I was surprised to find the depth of view was much improved.
This sketch shows the effect.

I am using only the front view over a total screen width of 5.75m, but as the side views are angled, the view, seen from the seat is a horizontal horizon (on the ground!), but as it is 2m deep, it gives a great illusion of depth.

I will post some pics soon.

Hans Krohn
04-17-2007, 12:01 PM
Hi Paul,

why is the center screen smaller than the side screens?


04-18-2007, 02:48 AM
Hi Hans,

The reason is the full size of the image I can project given the layout and space restrictions.

The size at 1750 is an exact fit for the centre projector image. The side screens are hinged where they join the front ( There is a door to the garden I need to use behind), and can be longer - as the image is projected at an angle, it is wider.

I could of course move the projectors back, but I have to be careful of getting shadows from the nose of the shell again.

My idea is when we move house, and have more space, I can open up the width, and adjust the projector rack without having to start over again.

Pictures added to EMB category

04-18-2007, 05:39 AM
You're ahead of me now Paul ... so now I'm watching your progress :)

We'll be firing up the 3 projectors again next week and doing some development work. Not sure if we'll bounce off mirrors or go direct like you have ... we'll see how the tests go. Would be good if we could mirror-curve a back-projected image.

04-18-2007, 10:46 AM
Hi Nic,

I was thinking the same thing this morning, but haven't found a source for the acyrilic mirror.

The beauty of the setup, is it would be easy to move the projector rig to behind/above the screens, and curve the MDF - just means making a curved mount.

Still, one thing at a time :p
Waiting for my new Routech yokes and a bunch of stuff from FDS...

04-18-2007, 10:58 PM
;) Hi! Did you see this? Notice the mirror and the Sintra.
Acrylic mirror installed and reflecting onto the 4x8 sheet of sintra.What ever that is?

:D http://www.biagettis.com/737simproject/737simproject_008.htm


04-19-2007, 06:13 AM
Yeah I experimented with a curved mirror a few months back. Got it from a plastics workshop, it's around $90AU per sqr metre.

The Sintra is the stuff they make political and real-estate signs out of - 2 light, flexible plastic surfaces back-and-front wedged together over a honeycomb core (about 5mm thick all up). Got 2.5m x 1.5m for about $50AU.

Its amazing how far you can bend the mirror - I got to about 30 degrees. I put 2 L-shaped aluminium pieces down the sides and 2 threaded rods between them, wing nuts on each end , and you can tension them up to get the curve you want.

With a short thrown distance of about 1m and a screen distance of about 2m the effect was amazing ... display width almost doubled. I curved the screen to the same curve as the mirror and voila - no warping of the image. Only thing is - if you see other aircraft pass in front-of-you they look a bit stretched :). Slight loss of image quality, acceptable though.

For a single strecthed image it's worth experimenting with. Not sure how it would go with 3 projectors .. you couldn't curve the 2 side displays very far otherwise the image would stretch too far and you'd get wierd movement cues at extreme left and right. Also tricky to line up the 3 images!

Hans Krohn
04-23-2007, 11:33 AM
Hi Nic,

how easy it is to set up the views for 3 projectors depends on the mount.

I am now designing a mount for my 3 projectors. It will allow for fine adjustments and requires only one attachment point to the ceiling. I will post my solution here once it's ready!



04-23-2007, 11:56 AM
I used a flat screen TV mount for my projectors (mounted horizontally ie ceiling not wall) - this gives around 45 vertical and 360 rotary (forgetting the cables).

My original plan called for threaded rod (the savior of sim builders) to adjust the height, giving millimeter control, with a similar rod to control direction.

That's still the plan, of course, but as my master mechanic said when I was an apprentice (he was from Yorkshire) sometimes "the rack of the eye and skew of the gob" method still works. I think in Australian that is called "she'll do mate"

Of course neither of these methods work in Germany, so I'm looking forward to Hans' plans. ( :-P )

Sorry, Hans, looking forward to your great ideas!

04-23-2007, 03:28 PM
What do you think of those security convex mirror which are made acrylic found on supermarekets and roadside. I contacted one manufacturer of those and asked if they are able to make concave they answered and quoted folowing.I am working for a company which import allkind of stuff from china. I think that china is the answer for homebuilder to get reasonably priced parts and materials.I am in planning process of building the simpit and do not have much knowhow yet. Hope i can use my work connection to get hold of good stuff for whole simcommunity.

Dear Sir,

We can make concave mirror. Following is the details:

1) Material: Acrylic
2) Weight: 0.47KG (Dia. 500mm)
3) EXW Price:
USD 20.2/pc (Dia. 500mm)
USD 91.0/pc (Dia. 1000mm)

04-23-2007, 07:07 PM
Security mirrors can work. Trouble is, you can't adjust the amount of curve on the mirror.

Hans Krohn
05-24-2007, 05:29 AM
Hi all,

there is no way to avoid the light spill. Three big lit screens will light up a room just like any other light source would. The same goes for backlit screens - there's anyway light coming from the screens.

I found that in a darkened room the light coming from my 3 screens during a daylight flight is not disturbing at all. As a matter of fact, I will still need to put some kind of lighting in my cockpit, because inside it is too dark.

Contrast problems appear only in certain situations, like a steep bank with one screen all bright (sky) and the other screen all dark (mountainside for example). In this case, contrast on the screen that displays the dark ground is not too good. Details tend to grey out.

A very cool effect from using beamers: When I pitch down and most of the sceen surfaces display ground (instead of sky), the whole room suddely get's darker. It is felt like an environment change that happens all around you...

I use my beamers in economy + cinema mode (this is the darkest possible setting) and found that it actually yields far better results than setting them to full blast.