Resolution locked to 1024 x 768 on monitor and projector

[farquea]

can anyone explain a problem we are having. We have a setup where by the projector clones the image on the computer. We have a VGA to wall panel VGA whcih then runs to a projector on the ceiling and then a VGA out on the wall panel which is plugged into the monitor.

 

The widescreen monitor we use, its native res was 1920 x 1080. If we just plug the monitor straight into the wall panel, we can only set the resolution on the computer to 1024 x 768. To get it to display 1920 x 1080 we had to plug the monitor directly into the computer and set it. Once set, we then plugged everything back in using the wall panel and the projector and monitor were displaying 1920 x 1080 res, albeit quite small on the board which I think would need the projector moving back in order to fill the board. But then once we reboot the computer something forces the resolution on the computer back to 1024 x 768. So by going through the wall panel the res is being forced to 1024 x 768 and not really sure what it is doing this.

 

Anyone know what causes this?

[plexer]

What is the native res of the projector?

 

Ben

[glennda]

What is the native res of the projector?

 

Ben

 

Sounds like the projector will only do 1024 x 768.

[farquea]

it is a NEC VT59 and ye just looked it up and says the native res is 1024 x 768. So is this default or a max res. as it seems to keep setting the computer default res to this resolution, is there a way to default it to another res?

[plexer]

Disconnect pin 12 in the faceplate

 

Ben

[plexer]

You want to be driving the projector at its native res.

 

Ben

[farquea]

ok, so at the moment we are using a 17" 4:3 monitor. we are buying some new 22" widescreen monitors, along with a new Promethean 387 board which widescreen. So i want to be using the highest possible res on both the PC and the projector which fills the board. So should i be going for a widescreen projector?

[plexer]

If you're buying a new board that is 16:10 widescreen then ideally you want a 16:10 projector however the maximum native res of the projector is still likely to be a lot lower than your monitors.

 

The only option you have is providing 2 different resolutions by extending your windows desktop to the projector rather than using clone mode.

 

Ben

[Abe]

ok, so at the moment we are using a 17" 4:3 monitor. we are buying some new 22" widescreen monitors, along with a new Promethean 387 board which widescreen. So i want to be using the highest possible res on both the PC and the projector which fills the board. So should i be going for a widescreen projector?

Yes!

 

Be aware there are two slightly different widescreen ratios available (16:9 and 16:10). I was just trying to find out what aspect ratio the Promethean 387 is and think it is 16:10, whereas any full HD projector (1080P) will be 16:9. The cheaper widescreen projectors do tend to be 1280 x 800 (16:10) but this native resolution may not look very good on your 22" monitor, although using 720P mode may be a reasonable compromise to look OK on both projector and monitor images.

[farquea]

so is it not unusual for the native projector resolution to knock down the computer resoltution to the same? ideally i want my monitors to be running at their max native res and the projectors doing the same so is this not possible?

[Marci]

Perfectly normal. Computer can't output the same thing to two screens at different resolutions. Both screens must be at same resolution. Maximum resolution will be that of the lowest spec'd item you're connected to. If I set my PC up to output 1920x1080 to my 50" plasma, and then clone it to a projector that only supports 1024x768 tops, then BOTH displays will run at 1024x768.

 

To run the two at different resolutions, you want to run them in desktop extend mode rather than clone, but then you can't show the same thing on both screens. One acts as an extension of the other, so you have to drag the app off one screen onto the other screen.

[gjdb]

We use 22" 1920x1080 screens on all our standard student desktops, but all our active board desktops are equipped with 17" 1024x768 monitors and so are the projectors.

Higher resolutions on active boards are not needed anyway, so why spend a lot more money on monitors and proctors?

[Busybub]

The only option you have is providing 2 different resolutions by extending your windows desktop to the projector rather than using clone mode

 

^ wot Ben said

[farquea]

we are upgrading the whole I.T suites and wanted to have some nice 22" monitors on the teacher PC's rather than the old small Dell 17" 4:3 monitors. So i think as we have the money we will go for a widescreen projector which i believe will allow us to set the desktop res to 1280 x 800 rather than 1024 x 768 which i imagine will look pretty ugly on a widescreen monitor.

[Marci]

If it's that essential that folks get to use their 22" monitors at native resolution, just get a projector which supports 1080P HD, which means it therefore supports 1920x1080 resolution over VGA cable. The projector itself has options to shift it's output format between 4:3 / 16:9 etc regardless of it's incoming resolution (ie: squish or stretch).

[farquea]

ok this is confusing me now. The projector i'm trying this on is an NEC NP305. On the spec sheet here: NEC Projector NP610 NP510 NP410 NP405 NP310 NP305: Projector Lineup | NEC Display Solutions It says the max res it can do is 1600 x 1200. But yet it keeps forcing the res to 1024 x 768!!!! there is a setting in the menu to enable WXGA mode, turned that on and nothing happens and i've played about changing the aspect ratio but still it wont let me up the res on the computer. Is this normal or what?

[farquea]

so i've figured out the problem. The problem occurs when you use a VGA extension. a single VGA cable from computer to projector allows us to change the res to anything. One you add an extension cable it only allows you to go to 1024 x 768 or 800 x 600. So i'm assuming the vga wall panels we have installed are causing the same problem and acting just like an extension. With the extension we tried removing pin 12 but still wont work. So i know the cause of the problem now, just not how to fix it if i want to use a projector and clone it to a monitor. any ideas?

[kevsach]

Farquea,

 

it sounds like your source device is struggling to read the EDID information of your projector. This is kind of the opposite problem to that being described by one reply of removing pin 12 from the wall plate (pin 12 carries the EDID display information). What you probably need is something to emulate the EDID information at the source end.

The best way to check this is to download the free Extron EDID Manager software from their website (extron.co.uk) this will show you the information the PC is receiving from it's display devices, i get the feeling it won't show anything, or have corrupt information from the projector. If this is the case you need a small in-line box such as the Extron EDID 101 device, which will allow you to either capture the exact projector EDID file and present it to the PC at the earliest point in the signal chain, or manually select the output res/refresh you require the PC to output.

 

Regards

 

Kev

[farquea]

i've figured it out. I just had to disable the EDID info on the computer graphics card, and that let me set the correct res on my monitor which the projector then follows suit, so its all fixed!

[glennda]

i've figured it out. I just had to disable the EDID info on the computer graphics card, and that let me set the correct res on my monitor which the projector then follows suit, so its all fixed!

 

TBH your pretty lucky - some Projectors tend to just say signal out of range if you try that!