What's the best projected image size using projectors?

[Tomlin]

Hi guys

To all of you who've been working with large screens via projectors, I have a question for you that I have meant to ask for a quite a while now.

I have a nice little projector that is capable of producing a nice size image, and I have plenty of room, so that's not an issue. My only limiting feature is the max resolution of my project, being a native 800x600 and up to 1280x1024 or 1024x768. This particular projector has not been used for my sim yet, but Ive played some console games (COD4 and Halo3) and it looked great. In the past I borrowed a lessor projector for the sim and it looked good too. I simply mounted the projector over the sim then and got the best image possible from what I had to work with. Now I have a large room all to myself and was wondering how big I should aim for.

So, since the 'world' is as big as the world, then how do we determine how big our forward out the window view should be projected to? Seems like since the runway in real life is typically 100' wide or more that we should aim to have our projected image as large as possible before it becomes too grainy (and assuming we can get the image to show properly without distortion).

What are the thoughts on this, when building a full scale 'pit?

[rt72]

Good question. I've been wondering this myself. There's lots of stuff about viewing angles etc... but I haven't seen much in regard to this.

[dcutugno]

I think the best for us all is a special custom BGL scenery, that will contain measures and poles with height written along them placed at every 45 degree of angle for visual alignment.

So someone with good skill on scenery design can make one.

This was an idea that popped in my mind along time ago, but never asked.
What do you think guys?

[Tomlin]

You know, I just had a funny thought...and before people start to panic by having thoughts like:

'oh no...it's just not the right size...my simulator is waay bigger than my projected runway is...'

...we must remember that our brains do an excellent job of corolating the size of the projected runway with our physical sim pits, thereby making it in our mind that it's not so off, so to speak. Case in point, when using my own full size Learjet sim before, the image up front was as big as I could get it for the time, yet it was no where near the scale it should have been, however it posed no issue since my brain was able to corolate a difference between the real physical size of the sim, and the projected image out front. An extreme example is when folks that have no projection system but only a 17" monitor for their forward outside visuals, they too have no issues, it's just not as fun!

Hence, my question as to 'how big should we aim for?'

[Tomlin]

I think the best for us all is a special custom BGL scenery, that will contain measures and poles with height written along them placed at every 45 degree of angle for visual alignment.

So someone with good skill on scenery design can make one.

This was an idea that popped in my mind along time ago, but never asked.
What do you think guys?


This is a very interesting concept. I for one think it might be useful for what you propose. Speaking of, what exactly is the hight adjustment bars/POV/sight tool that are usually located on the center post of larger aircraft used for (real world)?

[sbecker777]

Eric and everyone,
this is also a topic I've thought about for many years. The answer is just what our friend <b>dcutugno</b> suggests- BGL files set up for simmers to get proper sizing of projected images. I've started such a project.

In this scenery, I've modeled a set of 180 poles each 50ft high set in a 200ft diameter circle- one pole every 2 degrees. I place/slew my plane in the exact center of the circle of poles.

Based on how many poles I count at a given zoom, I can accurately and empirically obtain the actual horizontal Point of View (POV) in FS.

Next step is to model larger objects that I can accurately measure, and with a given distance from the object, measure how "big" it appears a given distance from my eyes. Translate that data to a BGL object to be placed in FS, and put the pilot's eyes the same distance from the known object.

Zoom or move the projector until the object in FS is the same size physically on the wall/screen as the real-world object and that's how I get the real world to be the same size as the virtual world.

Thoughts?
Steve

[Tim]

When can we try it?

I remember a post, I believe at Avsim, a few years ago regarding something similar. I'll see if I can find it again.

[warvet]

Well I did alot of homework on this when i was creating the curved mirror concept for FS and I deduced that a zoom of 1.25 is as close to realistic as possible. Secondly as far as image size it needs toi be big enough to go above your sim windows so you dont lose the illusion avg aircrft windows 18-24" high at highest point so image being 40-60
' is more than enough, however the further away from the front window the bigger the image needed. Suggestion put screens close to sim windows.JMO

Tim
a340
Canada

[Matt Olieman]

Would love to have David C. Allen in on this.... He's done a tremendous amount of research on this... :)

Matt O.

[Tomlin]

Thanks to ALL of you for your input- Im glad that it was a topic that interests many folks because as I said before, you certainly can enjoy your sim with a smaller monitor and a full size cockpit until you are able to get something larger, but I have a feeling that there will always be some sort of concession unless we had an absolute large room for a huge projector throw, or a huge budget for a collimated display like the big boys use, which basicly follow Tim's idea of having the image very close to the window, but the collimation throws a curve ball making it look like it's much farther away for depth perception.

Anyhow, Im looking forward to everyone's ideas and inputs. For now, I will continue to use as large as I can project and feel comfortable with! :-)

[dcutugno]

Eric and everyone,
this is also a topic I've thought about for many years. The answer is just what our friend dcutugno suggests- BGL files set up for simmers to get proper sizing of projected images. I've started such a project.

In this scenery, I've modeled a set of 180 poles each 50ft high set in a 200ft diameter circle- one pole every 2 degrees. I place/slew my plane in the exact center of the circle of poles.

Based on how many poles I count at a given zoom, I can accurately and empirically obtain the actual horizontal Point of View (POV) in FS.

Next step is to model larger objects that I can accurately measure, and with a given distance from the object, measure how "big" it appears a given distance from my eyes. Translate that data to a BGL object to be placed in FS, and put the pilot's eyes the same distance from the known object.

Zoom or move the projector until the object in FS is the same size physically on the wall/screen as the real-world object and that's how I get the real world to be the same size as the virtual world.

Thoughts?
Steve

Can i have this scenery?

[Tomlin]

Hi all

I just found a neat little utility for figuring all kinds of measurements that may prove helpful in planning your visual system. I love it and it's going to be put to the test over the next few days.

http://www.projectorcentral.com/Epson-PowerLite_S3-projection-calculator-pro.htm

[ADW]

You might also try this little utility. Use the 'Screen Size Calculator' button that is available when you view any projector's details.

http://www.projectorpoint.co.uk/projectors/Epson_EMP-400W.html#

[BHawthorne]

Actually, a "how-to" FAQ for surround projection might not be a half bad idea. There are a few things I really think that are important that might be covered.

1) First curface mirrors.
-How to shorten the projector throw
-Why first surface and not just any old mirror
-Affordable sources for first-surface mirrors
2) 16:9 vs. 5:4
-How screen aspect ratio directly effects immersion and screen design
-2x 16:9 or 2x 5:4?
-3x 5:4 TH2G?
3) Screen design considerations.
-Portible design?
-simpit room dimentions and realistic projector throw dimentions
-Affordable screen material sources
-misc other considerations
4) Software considerations
-Sol7
-SoftTH
-misc other software

I'm not at a point where I can definitevely answer half of those questions, but I know between all of us in the forums most can be outlined in detail and posted as a FAQ.

[alaxus]

A quick and dirty way.
In Tomlins case seeing he is using a learjet.
Find a learjet parked on the tarmac somewhere and taxi up to it. This should allow you to set the view height as you will be looking straight into the pilots eyes from where you are sitting. You should also be able to measure the width of the cockpit to set your perspective. This should be easy as the lear is about 1.6 meters across, your projector should be able to project this image size.
One thing to watch with projectors is the flyscreening, a 800X600 will be worse than one using 1024x768. I have a 1024x768 projector and I sit about 2 meters away, and its just on the flyscreening limit.

my 2c :D

[BHawthorne]

One thing to watch with projectors is the flyscreening, a 800X600 will be worse than one using 1024x768. I have a 1024x768 projector and I sit about 2 meters away, and its just on the flyscreening limit.

I'm assuming you mean the screen door effect LCD projectors have? Really, you get so used to it if you run LCD projectors that you pretty much forget about it. Isn't this issue gone in DLP projectors?

[Tomlin]

A quick and dirty way.
In Tomlins case seeing he is using a learjet.
Find a learjet parked on the tarmac somewhere and taxi up to it. This should allow you to set the view height as you will be looking straight into the pilots eyes from where you are sitting. You should also be able to measure the width of the cockpit to set your perspective. This should be easy as the lear is about 1.6 meters across, your projector should be able to project this image size.
One thing to watch with projectors is the flyscreening, a 800X600 will be worse than one using 1024x768. I have a 1024x768 projector and I sit about 2 meters away, and its just on the flyscreening limit.

my 2c :D

That's a decent way to do this man! Thanks for that idea, I will try it to test where I am now. Another thing I do is do the exterior view on the rear to insure the a/c is on the center line and then I go back inside for my fwd view and insure that I minimize the 'crab' effect. So far, I really see no issue with it like so many others have. I have set my view/eyepoint cfgs per the Nic D method, and it works pretty good. I will have some update pics soon!

[AchillesP]

Hello to all,

This is the best software I ever find for visual calculations accoriding to room shape, size and the type of projections frond, back, one mirro, two mirrors etc. The result is that you get all the figures as pdf together with the drawings and the program calculates also the best projector (firm and type). You must create an account first.

http://hcinema.avtool.net/site/index.php?lng=en

Best regards,
Achilles

[Matt Olieman]

Unfortunately I get this when I try to register :(

<!-- class="sidebox" id="language" --><!-- id="col3_content" class="clearfix" --><!-- Mittlere Spalte -->Fatal error creating page!

Please contact the webmaster.

[AchillesP]

Unfortunately I get this when I try to register :(

<!-- class="sidebox" id="language" --><!-- id="col3_content" class="clearfix" --><!-- Mittlere Spalte -->Fatal error creating page!

Please contact the webmaster.

Have you created an account? If yes, forget the message and at the left side bar click to create new project. Then use the avTool. I checked right now and works fine. I get also this message.

Achilles

[alaxus]

I'm assuming you mean the screen door effect LCD projectors have? Really, you get so used to it if you run LCD projectors that you pretty much forget about it. Isn't this issue gone in DLP projectors?

No its still a issue with DLP's as well. Each pixel is still surrounded by a tiny black line. You notice it mostly when you have a bright blue sky environment, which is where I have set my limit. Any image darker than this and the screen door issue reduces greatly.
My eyes are a bit sensitive on this issue, as I can also see the pixels on my 42" plasma tv (848X480) from about 3 meters away, I find it quite annoying.

Each to there own I reckon, to some it may be a issue, others may not even see the screen door effect.