Middle monitor showing left monitor when DCS focused

[Veen]

have a fresh install of Windows and DCS, 3 screens.

The main issue I've got is that whenever I have DCS in focus the middle monitor switches to the image of the left monitor.
I've googled around some and removed the saved games folder and the Temp\DCS folder.
Did a repair/check on the file.

Kinda lost on what to do after all that. Anyone got a clue what the issue could be there?

I've attached the dcs log and DxDiag file in case they are useful.

dcs.log DxDiag.txt

[Leg2ion]

Hi @Veen. What is your PC monitor setup, and what is your monitor setup file showing (not sure what 'DCS in focus in middle monitor' means?). Ideally you need to align your monitors in your PC, then transfer those settings to your monitor setup and in game settings.

 

This is a really good guide albeit the end result is to export MFDs - but gives a really good basic setup:

 

[Veen]

Hi Leg2ion

I have 3 1440p monitors side by side
So one left one middle and one right
I am using the unmodified 3Cameras monitor setup file which used to work until it didn't ^^'

It's really weird.
And it just gets weirder the more I look at things

Here's what it should look like / How it looks when I alt tab out of the game

Here's what I see when focused on the game

 

And here's a screenshot from windows when tabbed out of game

Third one is news to me
I see the left monitors image displayed on middle monitor while a screenshot just shows black

 

[Leg2ion]

Which Monitor is your 'main' in windows? 

[silverdevil]

On 10/18/2025 at 9:49 AM, Veen said:

3 screens

get the resolution width of each monitor. in DCS you are basically making one very wide monitor. then you have to modify an LUA with the appropriate parameters.

this forum may have your answer.

https://forum.dcs.world/forum/999-multi-display-support/

i have one monitor so i cannot share my file with you. say i have 3 exact monitors 3440x1440. 3440x3 (10320) would be my number. 

[MAXsenna]

If you don't feel comfortable editing the file yourself. Helios is an option to help you easily build it, even if you don't plan on exporting anything.

Sent from my SM-A536B using Tapatalk

[jonsky7]

On 10/18/2025 at 2:49 PM, Veen said:

have a fresh install of Windows and DCS, 3 screens.

The main issue I've got is that whenever I have DCS in focus the middle monitor switches to the image of the left monitor.
I've googled around some and removed the saved games folder and the Temp\DCS folder.
Did a repair/check on the file.

Kinda lost on what to do after all that. Anyone got a clue what the issue could be there?

I've attached the dcs log and DxDiag file in case they are useful.

dcs.log 42.27 kB · 3 downloads DxDiag.txt 104.42 kB · 2 downloads

You have two options when running 3 monitors

You can either:

1. Use all 3 monitors to effectively make one large wide display. All 3 screens will show a forward facing view which equates to a large Field of Vision (FoV)
or
2. Have a 90deg Left view, a Centre View, and a 90deg Right view.

I am assuming from your pictures, that your centre monitor is your "WINDOWS MAIN DISPLAY" and the left and right monitors are set to "EXTEND DESKTOP TO THIS DISPLAY", these are set in the Windows display settings.

You now have to make another choice, do you wish to keep the centre monitor as your main display, or could you live with the LEFT monitor being your main display.
The simplest method of getting DCS to do either option 1 or 2 is to set your "MAIN DISPLAY" as the left monitor.
Then
Option 1 - Select "1Camera" in the DCS settings and set your resolution as 7680x1440
Option 2 - Select "3Cameras" in the DCS settings and set your resolution as 7680x1440


If you want to keep your centre monitor as your MAIN DISPLAY then;

Option 1 - Use this monitor config file Veen-3 screen-1 Camera.lua  , in the DCS settings and set your resolution as 7680x1440 

Option 2 - Use this monitor config file Veen-3 screen-3 Cameras.lua  , in the DCS settings and set your resolution as 7680x1440

Save the files in SAVED GAMES > DCS WORLD > CONFIG > Monitorsetup


For 3 screens x 3 Cameras, you can alter the left and right view by adjusting the values of  "viewDx" where 0 is straight ahead, a value of -1 is left 90Deg, and 1 is right 90Deg.
So 45 degrees, or a forward-left view would be -0.5, but it doesn't work very well as a FWD-LEFT view duplicates parts of the cockpit, there is no way currently that I know of to align it.

Edited Monday at 04:12 PM by jonsky7

[MAXsenna]

7 hours ago, jonsky7 said:

but it doesn't work very well as a FWD-LEFT view duplicates parts of the cockpit, there is no way currently that I know of to align it.

That's a bummer. I was planning on going triple screens eventually. 

Just a thought. There are so settings to set the bezel size, but I haven't tried that and don't know how it works. Do you think that would actually help? 

Cheers! 

[Veen]

On 10/19/2025 at 11:06 PM, Leg2ion said:

Which Monitor is your 'main' in windows? 

Middle one

On 10/20/2025 at 12:31 AM, MAXsenna said:

If you don't feel comfortable editing the file yourself. Helios is an option to help you easily build it, even if you don't plan on exporting anything.

Sent from my SM-A536B using Tapatalk
 

 

Helios Good
Haven't used it yet since I just wanted to get DCS working before messing with that.
Tried using it to generate the file quickly but still having the same issue
 

23 hours ago, jonsky7 said:

You have two options when running 3 monitors

You can either:

1. Use all 3 monitors to effectively make one large wide display. All 3 screens will show a forward facing view which equates to a large Field of Vision (FoV)
or
2. Have a 90deg Left view, a Centre View, and a 90deg Right view.

I am assuming from your pictures, that your centre monitor is your "WINDOWS MAIN DISPLAY" and the left and right monitors are set to "EXTEND DESKTOP TO THIS DISPLAY", these are set in the Windows display settings.

You now have to make another choice, do you wish to keep the centre monitor as your main display, or could you live with the LEFT monitor being your main display.
The simplest method of getting DCS to do either option 1 or 2 is to set your "MAIN DISPLAY" as the left monitor.
Then
Option 1 - Select "1Camera" in the DCS settings and set your resolution as 7680x1440
Option 2 - Select "3Cameras" in the DCS settings and set your resolution as 7680x1440


If you want to keep your centre monitor as your MAIN DISPLAY then;

Option 1 - Use this monitor config file Veen-3 screen-1 Camera.lua  , in the DCS settings and set your resolution as 7680x1440 

Option 2 - Use this monitor config file Veen-3 screen-3 Cameras.lua  , in the DCS settings and set your resolution as 7680x1440

Save the files in SAVED GAMES > DCS WORLD > CONFIG > Monitorsetup


For 3 screens x 3 Cameras, you can alter the left and right view by adjusting the values of  "viewDx" where 0 is straight ahead, a value of -1 is left 90Deg, and 1 is right 90Deg.
So 45 degrees, or a forward-left view would be -0.5, but it doesn't work very well as a FWD-LEFT view duplicates parts of the cockpit, there is no way currently that I know of to align it.

 

Thanks for the Files and all the effort in explaining.
It sadly doesn't change anything.
 

DCS does display on all 3 monitors
But whenever I focus on DCS the image of the middle monitor gets replaced by the image of the left monitor after a second or two.


 

[MAXsenna]

 
Thanks for the Files and all the effort in explaining.
It sadly doesn't change anything.
 
DCS does display on all 3 monitors
But whenever I focus on DCS the image of the middle monitor gets replaced by the image of the left monitor after a second or two.


 

Do I understand you correctly that the DCS Main screen displays correctly, but when you jump in a cockpit the screens shifts around? That sounds like a Windows issue. There's a program called Display Fusion or something that can lock down the arrangement of the screens. I believe another user had to start using it to solve a similar problem IIRC.

Sent from my SM-A536B using Tapatalk

[Veen]

4 minutes ago, MAXsenna said:

 

 

Do I understand you correctly that the DCS Main screen displays correctly, but when you jump in a cockpit the screens shifts around? That sounds like a Windows issue. There's a program called Display Fusion or something that can lock down the arrangement of the screens. I believe another user had to start using it to solve a similar problem IIRC.

Sent from my SM-A536B using Tapatalk
 

Not quite
I start the game
Get 3 Black screens
I Alt-Tab out of the game and the main menu shows up on the middle screen, the others stay black as intended
I tab back into the game and after a second or two the middle screen turns black again

If I am inside a cockpit the same thing happens but it shows what exactly seems to be going on

 

When tabbed out all is good
See cockpit left, middle and right
If I tab back into the game my view switches to left, left, right


It's
such a strange issue

[MAXsenna]

@veen

Interesting it is! DCS shows when you LAlt+Tab OUT of the game => game loses focus? That sounds wrong, gremlins for sure. Apologies if it was mentioned above and I didn't see it. You have tried with checking the full screen option of course?

Sent from my SM-A536B using Tapatalk

[Veen]

Well
I think I figured it out now.
Use a displayport dummy and mirror middle screen onto the dummy

It's cursed but that's just anything involving Windows these days
here's hoping this fix will survive a couple reboots

Thanks everyone for helping out
Without the help here I wouldn't have gotten to the point of trying such a stupid fix

[jonsky7]

I've just seen your reply, but thought I'd post anyway, glad you got it sorted, though I have no idea what a displayport dummy is

 

What about setting your Left monitor as main for a test? 
DCS really likes the left and upper most monitor to be the main, I added a display table to the config file that is supposed to fix that, but it obviously hasn't

Try running with Full Screen off too, I personally don't see a difference in frame rate between them.

Delete these files/folders, DCS will rebuild them on start

C:\users\*yourname*\appdata\local\temp\DCS
Saved games\DCS\metashaders2
Saved games\DCS\fxo
Saved games\DCS\config\appSettings

I also made a couple of mistakes in the files, resolution wise, fixed them here 
Veen-3 screen-1 Camera.lua

Veen-3 screen-3 Cameras.lua

 

 

[Veen]

3 minutes ago, jonsky7 said:

I've just seen your reply, but thought I'd post anyway, glad you got it sorted, though I have no idea what a displayport dummy is

It's like... a little plug you plug into the graphics card and it pretends to be a monitor. It's a fake monitor.

 

4 minutes ago, jonsky7 said:

What about setting your Left monitor as main for a test? 
DCS really likes the left and upper most monitor to be the main, I added a display table to the config file that is supposed to fix that, but it obviously hasn't

Try running with Full Screen off too, I personally don't see a difference in frame rate between them.

Delete these files/folders, DCS will rebuild them on start

C:\users\*yourname*\appdata\local\temp\DCS
Saved games\DCS\metashaders2
Saved games\DCS\fxo
Saved games\DCS\config\appSettings

I also made a couple of mistakes in the files, resolution wise, fixed them here 
Veen-3 screen-1 Camera.lua

Veen-3 screen-3 Cameras.lua 1.23 kB · 0 downloads

 

 

I did see that you set the main monitor as the left one in the file. that didn't fix anything though.
I have deleted those files in the local appdata folder in an earlier step as well

There's some weird going on.
No idea what it is but I am definitely not gonna touch it anymore after it is working somehow xD

[Leg2ion]

30 minutes ago, jonsky7 said:

What about setting your Left monitor as main for a test? 

Just what I was about to suggest.  If in doubt - go back to basics. Even to the point of going back to one monitor - get it working then add in the other incrementally. May be obvious but helps understand what is going on in the weird world of windows. I run my screens left to right - 2 screens main display, screen 3 helios and screen 4 MFD outputs - adding them in incrementally when first setting up. If i attempted it in one hit it would be a steep learning curve.

Out of curiosity you haven't got any 3rd party software in use have you - sometimes people use it as a norm but don't think it affects things - DCS can be an unforgiving beast. (Spent a while with someone who was having issues - who after a few weeks declared when I disabled such and such it all worked).  This worries me:

41 minutes ago, Veen said:

Use a displayport dummy and mirror middle screen onto the dummy

What is the 'mirroring' bit about 'Use a displayport dummy and mirror middle screen onto the dummy' - is that causing the issue? Can you not display direct to the screen?

Edited Tuesday at 06:36 PM by Leg2ion