Image projection and warping for curved screens

[TheRedBarron]

Hi Folks,
My first post here on mycockpit.org! I am starting a very long term 737 build, starting with the visual system, so I can enjoy car driving and other sims while I plan the difficult bits.
I'm sure some of you will think I am being too picky, but I would really appreciate some help with the projection system. Here is the story so far....


I did a lot of research before building a 3.6m diameter 180 degree curved screen approx 2m high. Should be just big enough for a 737 (thanks to Ivar Hestnes for his sim photos). After much consideration went for the Optoma GT1080. Main reason being low input lag, good price and short throw distance. Will buy more of them if I can get the first to work well. Whilst I expected distortion when projecting onto a curved screen, I wasn't expecting the bottom of the image to be very flat and the top of the image to be so curved. See photo.

Although I can warp the image (have a copy of immersive display pro), the size of each pixel in the centre of the screen is much taller than at the edges. Seated in the pilot's position my eye can distinguish the pixels in the centre, but not at the edges. So I am looking for a way to fix this. Options considered so far.
1) Move projector closer to the screen - makes image too small (height wise).
2) Move viewpoint back - will lose immersion created by the 180 degree screen, plus won't have the room to move the cockpit much further back.
3) Use a 4k projector (cost is £6000 vs £600 for Optoma).
4) Use VR - then won't be a full sized sim project.
5) Use a mirror to warp the image - have tried with an acrylic mirror that I deliberately curved, but the light cone from the projector expands so fast that even an A4 sized mirror right infront of the projector does not reflect the whole image.
6) Use a lens to warp the image - still looking for one.
7) Build a high res projector using an Mac retina display (2440x1800). Have considered this, but it's another project in its own right and would be much larger that the Optoma - so run into space issues.
Dismantle the Optoma and tinker with lenses / mirrors. Easy to damage an otherwise good piece of kit!


What other options are there that could work given the usual constraints?


Many thanks


TheRedBarron

[iwik]

Hi,
Welcome to this crazy hobby. Pop on over to Cockpitbuilders.com where you will
find a wealth of knowledgeable guys. Only to willing to give advice.
Hope this helps.
Les

[TheRedBarron]

Thanks Les, will give them a try too!

[OmniAtlas]

Hi,
Welcome to this crazy hobby. Pop on over to Cockpitbuilders.com where you will
find a wealth of knowledgeable guys. Only to willing to give advice.
Hope this helps.
Les

On the contrary I would stay away from cockpitbuilders because It is run by an egomanic individual, and I've run into a few non-friendly users.

I recommend to use projector planning software such as the one developed by Fly Elise and that could assist with your problem.

Regards.

[iwik]

Ben,
I am just being helpful and don't try to colour others judgement, i have never had any problem so i will continue to provide as many avenues as i know to anyone asking.
Thanks
Les

[OmniAtlas]

Hi Les - everyone is entitled to their own opinion -- I am glad that forum is working well for you.

I still keep e-mails from these certain individuals and would be happy to share. I am not the first one to have problems, and likely will not be the last. In fact, I believe your fellow Kiwi (developer of Links2fs) also had an issue at one stage.

IMHO, Best if you are going to recommend another cockpit builder forum, to do so by PM.

Regards.

[TheRedBarron]

To be honest, I appreciate any help I can get, so thanks to those who are contributing.
With regards to the immersive design software, I am sure it would help if I knew how to correct the distortion with an optical solution.
That is the key piece of knowledge which I am lacking right now. I had also considered changing the screen shape to spherical or conical to tilt the screen towards the projector.

Any help appreciated

The Barron

[bindook]

Is the image the same when the projector is on the ceiling?

[fordgt40]

Ben, you would be better advised to follow your own advice, "IMHO, Best if you are going to recommend another cockpit builder forum, to do so by PM", in your case, the contrary argument can also apply!

This is not the place to air previous perceived grievances.

David

[TheRedBarron]

To bindook: yes the image is the other way up, so the top is nice and flat, but the bottom is badly bowed. I reckon after using warping software I get an image about 700 pixels high in the middle and 1080 at the left and right edges. If I could just get 1080 across the image then it would be fine.