Do not use Spyder3 software but ArgyllCMS.
Contrary to its advertisement you cannot measure WLED with an Spyder3. It lacks spectral corrections functionality, it has some corrections in formare and cannot addapt to diferent LED backlights.

All Spyder are poor measurement devices, even the newer Spyder4 wich has spectral corrections feature only comes with one WLED spectra for white.

Try first ArgyllCMS/DispCalGUI and your Spyder3, if cannot match in Custom OSD mode, then move to a betetr measurement device: i1DisplayPro or the cheaper color munki display (same accuracy, slower, not support for LUT3D models)

Can you please explain about "color munki display (same accuracy, slower, not support for LUT3D models)"

You refer to 3D monitors?

Color munki Display is essentialy the same sensor as i1DisplayPro but it is blocked in firmware(not fixable) to make it slower. It also does not work with Xrite i1Profiler software, intead it works with poor results color munki software.

LUT3D calibration is internal calibration and gamut emulation feature of U2413, U2713H and these new Dell's wide gamut monitors. You choose any RGB gamut inside ist native gamut (sRGB, AdobeRGB and whatever gamma you like) and the monitor can be internally calibrated to these target.
It is called LUT3D because calibration is done at once for each RGB triplet. 3 RGB values in -> 3RGB calibrated values out, stored inside monitor.
"Usual" calibration like the one you perfor with a U2412M, P2414H and such models is "LUT1D calibration" and it is stored in graphics card LUT (avoid gamer nvidia and intel integrated  graphics to do this task, they can not do it properly). It is called 1D because each chanel coreccion is fixed for all color that share same componente value. For example, in order to make grey 200,200,200 neutral to whatever white you want, calibration says it should be 201,202,198. For all colors that share Blue=200 no matter what color is blue is continuosly corrected to 198. In a LUT3D this does not happen, correction is asociated to the whole triplet so blue=200 is corrected to different values varing on R and G values.

Monitors that support LUT3D calibration need a software to store these calibration corrections in monitor. Color munki display as "cheap solution" ins not supported. The sensor is teh same but slower and blocked to use this kind of software so you but the more expensive i1DisplayPro.
Said that, i1DisplayPro is pretty fast, about 1000 patches in 30minutes and the most acuutaed deviec to measure photography monitors under 1000 euro. It's about 200 euro

Since you do not have an U2413, you can work with Munki Display wich is about 130 euro. It is slower and its factory software is not good but you can use ArgyllCMS

ArgyllCMS /dispcalGUI is a free software package that suppord several devices including Spyder3 (with a USB driver) and this software vasty outperforms all LUT1D calibration packages. its better than munki software, better than i1Profiler, better tha SPyder software any version and batter than Basiccolor display (in LUT1D graphics card calibration).


So, first of all download and install Argyll CMS and displcaGUI
http://www.argyllcms.com/
http://www.argyllcms.com/doc/Installing_MSWindows.html   (USB driver for Spyder3, munki display or i1DisolayPro do not need drivers)
http://dispcalgui.hoech.net/
Calibrate your screens. If they match you are done.

If they do not match and you have done it properly, then you need a new colorimeter: munki display (with its good features and bad features) or i1DisplayPro

Hi YUMICHAN,

Thanks for the detailed response. So yesterday after I read your 1st reply I installed Argyll_V1.6.3 binaries and the USB driver for the Spyder3 and also installed dispcalGUI.

These are the settings I used to start calibrating:

120cdm^2, D6500, 0.000001cdm^2, 2.2S 1xCurve+MTX

Settings also include Slow calibration and High setting quality calibration

It took about 4 hours to calibrate the 1st monitor and the ICM profile it created was:

U2412M 2014-06-14 120cdm^2, D6500, 0.000001cdm^2, 2.2S 1xCurve+MTX (default) - Set in Windows8.1.

Before the actual profiling it instructed me to calibrate the colours and white point.

What I was not sure about next was how to set a new calibration+profile for the 2nd and 3rd monitors without overwriting the 1st profile.

Can you please tell me:

1. Did I use the correct settings in the software for my monitor? Or do you suggest using other profiling methods?
   
   
2. How to proceed without overwriting the 1st profile?
   
   
3. Does i1DisplayPro calibrates printers as well?

Thank you!

1-Old colorimeter models are pretty slow...
Let's trust that your Spyder3 measuremets do not drift when device heats up

Calibration:

White & black level drift compensation OFF
Spectral correction: none
Whitepoint: 6500 Daylight
White Luminance: native (put it manually to your desired value in RGB balance window)
Black Luminance: native
Gamma: 2.2 relative
Black output offset : 0%
Blackpint correction auto off, 0%
Calibration speed: medium (let's try this to lower the wait)

Profile high quality
And in order to reduce time due your slow device: 3curves+matrix, ald large testchart for matrix profiles.
It's better an XYZLUT profile with smooth tables and >600 patches but this is not affordable with your device.
An I1DisplayPro can do a slow high quality calibration using spectral corrections for WLED/RGBLED/GBLED + XYZLUT profile with 600 patches in 40minutes, including CPU profile computation time. Pretty fast and accurate.

2-Just select 2nd and 3rd monitor on "screen" combo box in dispcalGUI. Any modern GPU should have as many LUTs as outputs (but poor performers in nvidia and intel)

3- NO, i1DisplayPro is a colorimeter. To profile printers you need an spectrophotometer: munki Photo (bad performer, 400euro) or i1Pro2 (1000 euro).
Anyway for photography monitors (I mean Dell Ultrasharps, Asus PAs, NECs, Eizos) is more acurate an i1DisplayPro than a i1Pro2. These xrite spectrophotometers have a bad optical resolution for LED displays (10nm), and make wrong asumptions about blue channel (and a little too in green for GBLED)

Hi,

Ok, so I'll run the tests again and I'll report about the results.

Currently, it took about 5 hours to calibrate and profile and the old monitor still is different than the newer. Could it be due to Burn-in time?

So, I'll do as you suggest, I'll purchase i1DisplayPro.

As for setting different profile per monitor, I have done the following:

1. In Display Device - changed to the relevant monitor

2. Created a profile

3. In setting I made sure I choose the correct profile for the monitor and installed the profile on the relevant monitor.

Thanks,

I'll report back.

Gil

I removed the windows colour profiles and changed only to the Dell default ICM.

Then, I did as you said but as soon as I cancelled the calibration, the monitor went a bit yellow.

So I had to change the Settings to sRGB and then measure RGB again. I did it on two screens and the results were that the white colour doesn't appear the same.

here is an exact description of how the new monitor looks like compared to the old one:

 - Text appears grey and lack contrast while the old one present richer black text.

- White appears with Green tint. White appears neutral.

I don't really know how to use dispcalGUI to the fullest. I don't know what all the settings mean... I'm lost... I feel stupid that I bought these two extra monitors now... I can't enjoy them when they are like this.

To make sure it's colorimeter fault and save your time, just do RGB gain window to D65 & 120cd/m, then cancel calibration before proceeding (just set desired white). Make sure that no calibration profile is loaded in windows color management, just driver's ICM "U2412M.icm".

So now, with near D65 daylight set & measured via RGB GAIN and without GPU calibration, put a full screen while 255,255,225 in each monitor and look at them from certain distance (in order to avoid glow) at 0 degree angle from panel's normal vector (front view).
If they are not very close it seems colorimeters fault.
This can be done in a few minutes and save your time.

On monitor's OSD menu should be a "Presets"> "Custom color" mode. You need to use this to set manually RGB gain/brightness/contrast and attain desired white manually.

sRGB mode is a factory calibrated mode to near srgb gamut (reduced blue gamut) and sRGB gamma curve. Its white cannot be tweaked in moditor, graphics card LUT should do this work (loosing a little contrast to fix whiet)  which means full calibration (and wait 1hour as you said before).

Try custom color first.

I tried both of your suggestions, and the monitors still look different.

Is there a way I can provide you reports from dispcalGUI?

Mediafire or any other public direct download server. Upload HTML (for ICM validations only)
For RGB gain and default profile it would be faster to run a calibrated report & uncalibrated report and paste the relevant content of LOG info window here.


Anyway if you did properly Custom color an RGB gain adjustment manually to less than 1dE from D65, it seems to be colorimeter's fault (I'm not there to see it, but it seems to be that).

1st attempt before you guided me on calibration:

https://mega.co.nz/#!slZ3kJSK!dY4d-s_-ckpKtaV44h-ErsVxK5ar75blo7-KAjpcA7A

2nd attempt after you told me what to do:

https://mega.co.nz/#!dgZFBKyD!IYvl6uB0wrVeJFElPvOWioSd5gjtxlL6xIxSGzAtfLo

Please let me know what you think.

Thanks for the help!!!

I was actually asking for "tools -> uncalibrated screen report" and "calibrated screen report"

From 2nd attempt the two white points seesm to be very close, but both screens seem weird.
Center calibrated gamut seems to be near perfect sRGB but Custom Color mode in WLEDs has some extended blue under L*a*b*. Are you absolutely sure that on center screen 2nd attempt you used Custom Color mode and not sRGB mode?
Right screen 2nd attempt has an extended gamut beyond sRGB like in saturated WLED backlight from cheap korean monitors (but near sRGB).

A bit weird... but ArgyllCMS is working properly: calibration kept more than 95% RGB values for both screens. Try to rent a i1DisplayPro.

Thanks for the reply.

1. As soon as I get home, I'll send the reports again as you specified.

2. I just purchased i1DisplayPro online so it would take about 4 days to arrive

3. I used Customer colour mode for the Centre screen but I don't mind to run that again just to be on the safe side. I used your guidelines when I set ArgyllCMS settings. I'll provide a screenshot before I run the test so you can see the settings.

4. If I provide you with serial numbers, are you able to verify to authenticity of the monitors? Since the right screen and the left (which I didn't provide its reports) are both the new monitors.

5. Thanks again :)

4- Sorry, no. I'm not related to nor employed by Dell so I have no access to that information.