Average lumens these days is around 1000 but getting higher all the time. The contarst ratios on DLP is increasing also.Some of the Negatives are:-projectors run very hot as the bulb is in very close proximity to the main circuit boards-short bulb life (1000-2000 hours typically) but is increasing.-expensive bulbs ($300-$500 USD)-noticeable pixellation (LCD only) Deltaflight wrote about this in another post.-poor black levels-built as disposable units, you

Alkit,I am using an NEC 150 DLP with excellent results in a 12X8 room. Under $1000 on EBay.To those of you using mirrors and a backlit display - can you post more info on how to do this? From the perspective of space this sounds like to way to go. My image is huge - almost too big, so I'll have to figure out how to make a large screen and curve it a little... backlight and mirros is a much better solution considering my space constraints.

MirrorsI saw 2 waysFirst is shown on the pic. Nice and simple. Escpecially in smaller rooms.Method 2 is brilliant. It gives 180 degrees of vision with one beamer. If you click on the link you can see the movie made in the sim.http://members.chello.nl/p.leerentveld/simulatorflights.htmI read about this in "Piloot & Vliegtuig" , a dutch magazine (pilot and airplane). In the article was a small 3d drawing , how they did this.The beamer is at the same location as in method 1. But first it gets to a mirror that splits the emitted light in 2. The left part goes to a bigger mirror mounted to the left, and the right part to a mirror on the right. (3 mirrors in total). This second 2 mirrors bounce the light back to a 180 degrees curved sheeth (back projection).I think this is really the way to go. The video speaks for it self. In the future these guys are planning to commercialise this projection system.It seems very cheap to make. You only need one beamer and it looks even better than the systems I saw with 3 beamers.RegardsNorbert(http://home.wanadoo.nl/norbert.bosch

Hello Gaz,Thanks for your advice. I think this can be a text knowledge in thid forum.DLP sounds really good in performance, but bad to pocket. Really pay to fly the simulator! I will see if I can afford it when I make the final decision.ThanksAlkit

Hello Norbert,Thanks for your info.For my cockpit, it will be built inside my room, the front side will attach to the wall. I will put the projector at the top of shelf at the rear. Is there any method can make the projection like the link you shown in my room configuration? One projector for 3 sides-like projection (curve display). Alkitwww.alkit747.com

.......... the front side will attach to the wall..........Well in that case you will get into troubles, you certainly need 2 to 3 meters I think.I just tried to scan the picture from the magazine I wrote about with the multimirror 1 beamer display system, but my scanner is not working anymore.So i made a rough sketch (not to scale). You will see the point of it in the pic.RegardsNorberthttp://home.wanadoo.nl/norbert.bosch http://forums.avsim.net/user_files/70239.jpg

Its quite easy actually... Halfen the distance by mirroring the projection... :-)I use 2 bathroom mirrors fitted side by side on a wooden board. The bigger the mirror, the closer to the sceen it can be placed. I've drawn a quick sketch of what I mean. http://forums.avsim.net/user_files/69984.jpgHeh, nice portrait huh?The projector can be placed under or over the cockpit. It projects forward to the back of the screen and bounces back on the mirror to light up the back of the sheet. No more shadows from your head getting in the way :-)I use an ordinary bed sheet as a screen. You dont have to worry about the display getting reversed, because if you mirro it AND back-project the screen it takes out each other. Some construction, trying and invention apply :-)Cheers!/ Olle RamsbergSweden

Very niceBut is it not difficult to find the good position of the beamers and the 4 mirrors to make the both side view accurate and to eliminate the positioning errors ?Do you try with experiment or calculate it ?BOB

I do not have experience with this method (my project is not that far at the moment).As I wrote somewhere earlier in this thread:I read about this in "Piloot & Vliegtuig" , a dutch magazine (pilot and airplane). In the article was a small 3d drawing , how they did this.The beamer is at the same location as in method 1. But first it gets to a mirror that splits the emitted light in 2. The left part goes to a bigger mirror mounted to the left, and the right part to a mirror on the right. (3 mirrors in total). This second 2 mirrors bounce the light back to a 180 degrees curved sheeth (back projection).the link you can see the movie made in the sim.http://members.chello.nl/p.leerentveld/simulatorflights.htmLook at the movie at this link and you will be amazed. A normal baemer gives only a smal angle of view (have seen several movies of this on the net. This sim has a true 180 visual with ONE beamer. Unbelievable, This link is truly a must see.regards Norbert

With this mirror splitting method, wouldn't you have the same in-sim FOV (field of view - front view of FS only), just on a wider plane? Not like using 3 sources to get a larger FOV, i.e. 45,0,45.

Well , I thougt the same. Just a magnifiction of the normal limited viewangle but now bigger.Did you look at the movie in the link above?It looks very natural. I think they changed the zoom factor to overcome your problem.But again I liked to mention this metod on this forum. I have no experiance with it, but when I came to my visuels I certainly will experiment with this solutionh.Norbert

In fact, is it possoble to change the computer display setting for making one single projector to deliver ....may be 140-160 degree image with some help of mirrors...??Or we have to do it by three projectors in this case?Alkit

I told it before. Just look at the movie in the link. That one is with ONE beamer. The angle in the video looks very natural. It is not just a bigger monitor screen. So I think they changed the zoom factor.RefardsNorbert

This is an interesting idea. I have one question on mirrors that maybe someone can answer?I have heard that for rearward projection, the mirrors show be coated on the front and not the back. Is this true? If so, how much of a difference will it make?John

Hi John,It's a question of image quality (and budget). A rear surface mirror will have a ghost reflection from the front surface along with the desired rear surface reflection. In some applications the ghost image may be objectionable. Two common methods of reducing or removing the ghost are placing an anti-reflection coating on the front surface of a rear surface mirror, and simply putting the reflecting material on the front of the mirror.I would be surprised if a rear surface mirror used as described above produced an objectionable ghost.Mikewww.mikesflightdeck.com