View Full Version : Rear projector questions ?
spitfire9
08-25-2007, 02:47 AM
Has anybody tried a rear projection setup with 3 projectors and a Triplehead2go ?
Do you need a special projector to use rear projection ?
I would really like to use the 3 projectors with the Triplehead but headroom above the shell is going to be a problem.
It would be very helpful if there was a tutorial or some drawings of how big the screens would have to be and how far the projectors would have to be from the screen etc.
Thanks.
I'm using 3 projectors and back projecting with the TH2GO. Full explanation here: http://www.insitesolutions.com.au/737project/design_visuals_develop.htm
This is for wrap-around, but I've also run it in traditional TH2GO single view across one wide front screen, and that works fairly well also.
Ideal measurements are not really possible because everyone's space and shell is different. But keep in mind that the more square-on to the screen you can place each projector (or mirror) the better.
flightdeck
08-25-2007, 03:56 AM
Here you can find a very useful tool, to calculate beamer distance, projection size and more:
http://www.projectorcentral.com/projection-calculator.cfm
spitfire9
09-01-2007, 12:15 AM
NicD,,, just a couple of questions.
I am planning basicly the same as you for visuals,, a Triplehead2go with 3 projectors at the back of the screen.
1. How far from the cockpit windows will your screen be ?
2. How far from the projectors to the screen are you going. Also are you planning to use mirrors ?
3. How much will the side screens be angled from the front screen ?
4. What will be the size/area of the screens?
Using the projector utility that was previously posted (excellent utility by the way) I plan on using the Viewsonic PJ358. It gives a screen size of 40"x30" at 5'.
I would like to project straight from the projector to the back of the screens (no mirrors). Will this be a problem with the scenery being reversed ??? or is there a setting to reverse the picture on the projector or on the video card settings???
5. Just wondering if there are certain projectors used for back screening?
Thanks.
Just a few questions there :) Keep in mind that our dimensions are totally governed by a cramped space - so not ideal yet.
1. How far from the cockpit windows will your screen be ?
Ideally around 1.5 metres. Any closer and you notice the screen and loose depth perception. Much further then 2 metres and the room starts to come into view.
2. How far from the projectors to the screen are you going. Also are you planning to use mirrors ?
We are using mirrors due to lack of space. Distance at the moment (on the centre screen): 1m from projector to the mirror (pointing backwards), then 2.5m from mirror to the screen.
3. How much will the side screens be angled from the front screen ?
The ideal is actually right angle - 90 degrees. This may seem odd but it actually works well. You then have 2 corners, but if its not too obvious, and the corner itself is a bit of a curve, its fine.
4. What will be the size/area of the screens?
3m wide and 2.2m high (changing to that now)
The key is to set your eyepoint in the middle of each screen. So the captain's eyes should be aligned in the centre of the side screens, and will be a bit left of centre of the centre screen (but as close to centre as you can).
Also the closer you can get your projector aligned to the centre of the screen its projecting too - the better. Try to avoid using mirrors to angle the image if you can. We're only doing it because we have no other choice for now.
5. Just wondering if there are certain projectors used for back screening?
Most (if not all) current projectors have this in their built-in menus. You can turn images upside-down, as well as reverse them for back-projecting
spitfire9
09-01-2007, 01:27 PM
Thanks for the quick reply . Lots of good information there !
The room I have for the sim is about 17'x12'. I'm thinking I might have to use mirrors.
As far as any more planning on the visuals ,, the pit/shell will have to be finished so I can do some experimenting.
I might take a trip with a friend where we will have access to the real aircraft . I could take some measurements and sit in the cockpit and try to get an idea of how big the screens have to be so I can't see the edges.
My plan so far "was" a straight on project throw of 5' with 3 screens about 40"x30".
The screens were to be about 2' from the windows with the side screens at about 45deg angle.
I am thinking of building the screens into the front of a box that would (on the backside of the box) mold around the front of the pit ( with foam around the molded side) with the inside of the box painted black.
This would cut out all light and view from the cockpit to the sim room.
I was hoping that this box idea would give a little depth and still allow me to keep the screens fairly close to the pit.
Does this sound like a feasable idea ???
I really like Nicds set up and am impressed with the videos etc. But I don't think I have enough room for the bigger screens .
But like I said earlier,, more measuring ,thinking,,and planning. Thats half the fun about these projects anyway !
Westozy
09-01-2007, 06:17 PM
Something to consider. My first set up was bounce projecting off a mirror and it works good except - ordinary glass mirrors give two reflections which results in a bit of a ghost image being projected. Use a reflector that has the silver on the surface, Matt O knows what the stuff is called, the name of it escapes me right now.
Gwyn
The box idea sounds feasible. Painting it and your shell black or neutral is VERY important. Its a real shame that the guys who get their outside shell looking so good may have to do this to eliminate reflections and washout. With 3 projectors going there is alot of lumens bouncing around in a small space.
Your idea to experiment once the shell is done is the way to go. Honestly, you can plan this with CAD etc... but nothing beats actually moving the gear around and seeing what's possible. There are issues that arise that no amount of planning could forsee. So some general space planning is good for now, but your plans are going to need to be flexible when the day actually comes.
Good luck with it all, and keep us up to date with your progress.
It's a pity that some of the guys with finished examples of pits/visuals shown on this site don't share how they did it, and don't reply to questions. Inspiration is good, knowledge even better. That's what communities like this are for.
Trevor Hale
09-02-2007, 08:47 AM
It's a pity that some of the guys with finished examples of pits/visuals shown on this site don't share how they did it, and don't reply to questions. Inspiration is good, knowledge even better. That's what communities like this are for.
I for one Nic, have been following this thread, as I am using rear projection, however.. I only have one projector, spanning across my windscreen of my cockpit. I wish I would have the space and the money to add 2 more projectors. Even if I could afford one more projector, paying the thousand dollars for Bulbs every few years would keel me. I would have to say though that with your experience, I would consider you (and Expert) in this field. What you have accomplished with your visual setup is outstanding, I could only wish that one day I can have the immersion feeling that you have with your setup. Therefore, my comments would be insignificant compared to members like yourself.
Best regards,
Trev
Hi Trev - thanks, I appreciate your comments.
I think I'm just an early adopter of the TH2GO who's been prepared to try some new things. There are others around who have/are trying similar things, and I encourage them to share their findings for the good of the community.
There are many of us who cannot afford more than a single display at this point... but you guys should still be fully engaged in discussions, otherwise it may seem that multi-display systems are the only legitimate way to go ... which is not the case.
Another thing I'd add... given what I know about space limitations now I'd seriously consider going with 1 projector for the centre view, and 2 large flat-screens for the sides. This is a feasible and worthwhile option to consider. Some immersion would be lost, but considerable headaches would be saved.
Tomlin
09-03-2007, 08:22 AM
...seriously consider going with 1 projector for the centre view, and 2 large flat-screens for the sides. This is a feasible and worthwhile option to consider. Some immersion would be lost, but considerable headaches would be saved.
(my reply to that with this running thru my head as the dog licks my leg) I read something very similar time and time again, and I STILL adopted a Border Collie! Anyone who's ever lived with one or known someone with a BC dog, knows what Im talking about :-)
Nic, Thanks again mate- what you have done and shown has been the inspiration for many Im sure. I guess just like I stated above, you can save considerable headache, but from my side of the fence (who's never been on your side of the fence) I see how a lot of hard work has resulted in an awesome visual system for a home Boeing 737 simulator. Just to encourage you, think about what most of us here are doing- we are building a dang aircraft in our garages, bedrooms, and shops! So, yes- headaches, but I just love your visual system and dont know if I could ever consider changing the plans from a 3 projector wrap around to a single projector/LCD side view.
Regardless, I will too one day understand the difficulties of what youve done so great, if I choose to go that route.
One question on an item that did throw me though- You mentioned that if possible, have the side views projected nearly 90 degrees to the forward visual? That's certainly strange sounding to me, can you elaborate please
:-) ?
Trevor Hale
09-03-2007, 08:58 AM
Hi Trev - thanks, I appreciate your comments.
I think I'm just an early adopter of the TH2GO who's been prepared to try some new things. There are others around who have/are trying similar things, and I encourage them to share their findings for the good of the community.
There are many of us who cannot afford more than a single display at this point... but you guys should still be fully engaged in discussions, otherwise it may seem that multi-display systems are the only legitimate way to go ... which is not the case.
Another thing I'd add... given what I know about space limitations now I'd seriously consider going with 1 projector for the centre view, and 2 large flat-screens for the sides. This is a feasible and worthwhile option to consider. Some immersion would be lost, but considerable headaches would be saved.
I guess this would be a feasible option. I happen to have a 21" and a 19" CRT Hanging around, and I have considered attaching them to the Side Views. Guess I might have to consider this option. I would like to ask though, In order to get the side view, I can imagine the THTG works well with FL, F, FR Views, however If I want Left, F, and Right, I am not sure It would look right. I may need wideview computers, and as I am sure you are aware having 3 pc's that can run Flightsim in smooth operation, can be costly. I guess I will need to play with it.
For those of you looking for a good rear projection screen meterial that shows no projector hotspot, I have found that Vinyl shower curtain works best.
Trev - trick is if you zoom your 3 views out to around 0.45% in FS then the LEFT, FORWARD and RIGHT views actually stitch up well. We discovered this quite by accident.
Keep in mind that the left-forward and right-forward views are not 45 degree views, they are just extensions of the forward view further left and further right.
Eric - thanks for the encouragement, much appreciated. And guess what ... I have a cute border collie called "bella" ! :-) so yeah ... I know what you mean.