Edge blending...yes or no

[Maurice]

For a long time now, I have been against using edge blending because of the overlapped lighter areas which show up mostly at night. But now that I am raising my projectors, I will be moving them anyway and I am thinking of re-visiting the edge blending option.

So my question is aimed at anyone using edge blending (Nat? or someone else). Are you REALLY able to dim the overlapped portion enough so that when flying at night, you do not see a wide lighter area in the junctions. Or is that always visible no matter what you do to compensate for it.

Thanks,
Maurice

[ivar hestnes]

Can inform you that we have a system for reducing the night-flight problem. Send me an email if you would like to know more about it.

Scroll down the page, and check out the "deep-black" video 
http://univisualtechnologies.wordpress.com/

[Nat Crea]

GDay Mau

Im scared I might tip you over the edge with an honest answer!
OK, seriously...In all the visuals I have set up, from $1500 to $15000 projectors,
every overlapped region had the lighter band of light at night.
Some projectors were better than others( I forget which models), but they all look
good until dusk or beginning of dawn times.
The trouble is all projectors still emit a tiny amount of light, even if your scene is black...
I personally would never give up my daytime blended flying time...

Ivar, is the Deep-Black Module software or mechanical filter? Video looks great mate!

Nat

[Maurice]

Nat,

I've been over the edge for years now but I'm still here somehow . I think the light bands at night will bother be more than visible edge butting so I don't think I will use edge blending unless Ivar's solution is affordable & works.

Ivar, I will send you an e-mail for details but you probably should give more info here as I'm sure others will be interested as well. The video looks great by the way.

Thanks,
Maurice

[HarryZ]

Mauice,

I've just spent a couple of months using Warpalizer on my new screen set up with 3 projectors. Edge blending is one of the most difficult tasks to get right because you are mostly trying to deal with gamma correction,.

Daylight flying goes through various shades of many colours so the setting that may work well for clouds and ground won't work well for blue sky and vice versa.  Night flying gives you another problem in that the overlapped area gets a bit more light than the otherwise black sky and I still haven't got that issue fixed.

Supposedly the professional version of Warpalizer addresses this issue but unless you are doing this in a commercial setting, the cost would not be worth it for the average person.

Harry

[sluyt050]

I would not go for edge blending either. Even stronger: I would not go for warping at all. For a long time I concentrated on building a 210 deg. curved screen (3840 x 800 pixels). Then I realised that I simply do not accept a loss of vertical resolution due to warping (ideally I aim for 1080 or 1200). So I decided to go for 3 angled flat screens instead (I understood Scott is thinking in the same direction).

BTW, the only way for better 'dark' is to physically filter too much light out and/or using the projectors ECO mode or whatever. A software approach will not do (so well). I got this info from a home cinema projector specialist.

[DaveC]

My current setup also uses 3 projectors with edge blending (Warpalizer) which looks fantastic during the day.  I am moving to a new building next weekend so everything is coming apart and the visual system will be rebuilt.  I am planning on going to edge butting to eliminate the night problem.  While I am at it, I am also considering going with flat screens (maybe rear projection so I could use HD projectors since I have enough space for huge throw distances and keep the screens close to the cockpit windows.

I've really been struggling the past month with what to do.  The problem is my current visual setup really looks fantastic and I am afraid of changing to something that may not be as good.  Nat's visuals are really stunning and keep me wanting to stay with what I have, but rear projection flat screens with full HD would really increase the resolution and edge butting makes night flying look really spectacular.

[HarryZ]

Edward,

I've seen a couple of comments about a loss of resolution using Warping software but I've had exactly the opposite experience.  Prior to my current 135 degree curved screen, I used a single projector on a flat wall. Resolution was 1280 x 1024 with a projector whose native res was 1024x768.

I now have 3 projectors with native 1280 x 800 and Warpalizer and the view quality has improved. I can read the taxi/runway signs easier and the surround experience has added a whole new dimension of realism to my sim.  I was told before I started this project that "getting it right" was the important factor and that appears to have happened. 

I think the quality of one's imagine blending software may have a lot to do with it as well.  Going the inexpensive route in this instance may not be good in the long run.

Harry

[blueskydriver]

Just curious about a couple things here. If you front or rear project using 3 flat screens and you have angles, you would have to use keystone correction from the projector to get everything lined up. Now, if you edge butt or blend, you will have overlapping no matter what because keystone shapes the picture, but it does not remove all light. So, you will get the, I'll call it, "night light error" no matter which way you go.

Next, in stanard rear projection you lose lumens because you have to shine or project through the material. And, with standard throw you have the distance, so you need higher lumens from the projector to cover the distance and go through the material. With standard throw front projection you have the lumens, but the cockpit becomes an issue as to where it's located and/or if it's blocking the projectors or not.

Of course you could use mirrors, but you might have to pay more; however, I really don't think anyone has tried it successfully. Yet, there are a whole need breed of mirrors out today...look at these links:

http://www.da-lite.com/products/product.php?cID=10&pID=241

Surrounding Image Projection with Convex Mirrors

I wonder how these new mirror designs could work, if the screens were close to the cockpit and rear projection was used; assuming, you used a very high lumens projector(s)? Looking at the youtube video, it looks nice and easy, but nothing is ever nice and easy.

Personally, I am holding my breath for OLED in large bendable screens...okay, not in my lifetime, but one can dream right? In the mean time, I am sticking with curved screen and edge butting. I get wrap around, no image loss and no night light error. Besides, we all know that more time is spent looking in the cockpit then out, so I am not worried too much about it...

John

[sluyt050]

Edward,

I've seen a couple of comments about a loss of resolution using Warping software but I've had exactly the opposite experience.  Prior to my current 135 degree curved screen, I used a single projector on a flat wall. Resolution was 1280 x 1024 with a projector whose native res was 1024x768.

I now have 3 projectors with native 1280 x 800 and Warpalizer and the view quality has improved. I can read the taxi/runway signs easier and the surround experience has added a whole new dimension of realism to my sim.  I was told before I started this project that "getting it right" was the important factor and that appears to have happened. 

I think the quality of one's imagine blending software may have a lot to do with it as well.  Going the inexpensive route in this instance may not be good in the long run.

Harry

I recently got a demo by Nikola Gidalov, the designer of the Fly-Elise warping software, and he showed me clearly that due to the warping correction there always will be a vertical resolution loss. The larger the distortion that has to be compensated for, the larger the resolution loss will be. At a relative small radius screen it will become worse. So this is theoretical and applies for all warping software. That said, I can imagine that if the screen radius is considerably larger than 1.5m one could live with a (small) quality loss. For me it is a no go since I have limited space.

I did a quick test with 3 angled 27 inch flat screens (210 deg. view, 110 deg. angle between adjacent screens, 3840x800 projection, 1 FSX view for each screen) and I was quite impressed. It is a relative simple approach and no blending needed. An extra advantage is that this setup uses my  available room space more efficiently as compared to a curved screen. Of course it will always be a matter of personal preference too.

[nicd]

Had good success with mirrors.. back in 2006/7 in the early days in the old garage. Space was tight so had to use a combination of .. wait for it.. a curved mirror to rear projection for the front screen, and flat mirrors to front projection for the side screens. Meant lotsa tweaking and late nights but the end result was quite good.

Used bendable acrylic mirror and never had any issues with it.

Back in those days edge blending meant twisting a projector by 2 microns, then cursing and trying to move it back by 1 micron 

[Maurice]

Just curious about a couple things here. If you front or rear project using 3 flat screens and you have angles, you would have to use keystone correction from the projector to get everything lined up. Now, if you edge butt or blend, you will have overlapping no matter what because keystone shapes the picture, but it does not remove all light. So, you will get the, I'll call it, "night light error" no matter which way you go.

John

You are quite right about this John. The first time I set up my projectors, I tried using keystone corrections and this made things at night much worse than with edge blending (or same as edge blending without any brightness/gamma correction in the overlapping areas). Keystone correction is to be avoided  completely in my opinion.

Maurice

[Maurice]

I went back to the archives of a long time ago where that discussion was in full swing as well. Regarding the keystone effect, check the post by fdspcos where he explains what happens when you use keystone correction.
http://www.cockpitbuilders.com/community/index.php?topic=1403.msg10586#msg10586

The only way to avoid using keystone correction is to have the projectors perfectly horizontal and not tilted slightly down (or up) as you may need to do if the projectors are mounted on the ceiling. Originally, my projectors were pointing slightly down to fill as much visible screen (from inside the cockpit) as possible but now they are perfectly horizontal so I do not use any keystone correction at all.

It seems like history is repeating itself. I would have thought that by now, there would be a fool proof easy method to achieve what is seemingly unachievable (unless Ivar has a 'magic' solution) 

Maurice

[XOrionFE]

[I recently got a demo by Nikola Gidalov, the designer of the Fly-Elise warping software, and he showed me clearly that due to the warping correction there always will be a vertical resolution loss. The larger the distortion that has to be compensated for, the larger the resolution loss will be. At a relative small radius screen it will become worse. So this is theoretical and applies for all warping software. That said, I can imagine that if the screen radius is considerably larger than 1.5m one could live with a (small) quality loss. For me it is a no go since I have limited space.

I did a quick test with 3 angled 90 inch flat screens (210 deg. view, 110 deg. angle between adjacent screens, 3840x800 projection, 1 FSX view for each screen) and I was quite impressed. It is a relative simple approach and no blending needed. An extra advantage is that this setup uses my  available room space more efficiently as compared to a curved screen. Of course it will always be a matter of personal preference too.

I haven't had a chance to try out the flat screen approach yet.   I am very curious about your test and how it went.   Do the screens make it past the side of your cockpit ok?   do you feel you loose any sense of depth due to them being flat as opposed to the curved approach.   Do you have a picture of your setup?    I really like the idea of this but I have to borrow a pickup truck to carry the sheets to my house and just have been too busy on my cockpit rebuild but I am really interested in this.

Scott

[sluyt050]

I haven't had a chance to try out the flat screen approach yet.   I am very curious about your test and how it went.   Do the screens make it past the side of your cockpit ok?   do you feel you loose any sense of depth due to them being flat as opposed to the curved approach.   Do you have a picture of your setup?    I really like the idea of this but I have to borrow a pickup truck to carry the sheets to my house and just have been too busy on my cockpit rebuild but I am really interested in this.

Scott

You got me Scott! Actually my quick test was done with 3 x 27" monitors in the configuration as shown below. Sorry if raised the illusion of having done a full scale test. I am as curious as you are. Still, my monitor test gave me quite a good feeling how a larger scale setup would look like. I noticed for instance that with my head at the right location (eyepoint) the bending of horizontal lines, e.g. the runway sides, at the transitions from front screen to the side screens dissolved. It looked liked as if it was one contiguous natural image (of course I created the right 70 deg. views in FSX).

I do not have experience with a curved screen setup besides the 180 deg. setup I saw at Nikola's place. I am not building a cockpit yet so I cannot answer your question on how the difference would feel. I will report as soon as I make progress. I plan to start 2nd half of 2013. So it is still possible that you are first. (BTW, very impressive TQ overhauling video you made. My motorized Rev. Sim TQ will arrive in 2 weeks).

[HarryZ]

The only way to avoid using keystone correction is to have the projectors perfectly horizontal and not tilted slightly down (or up) as you may need to do if the projectors are mounted on the ceiling. Originally, my projectors were pointing slightly down to fill as much visible screen (from inside the cockpit) as possible but now they are perfectly horizontal so I do not use any keystone correction at all.

My 3 projectors are tilted slightly downward.  Instruction i got for the Warpalizer software was not to use any keystone function at all...the software adjusts what you need.  i did that and suffered very little if at all vertical resolution downgrade.

Harry