Colormunki versus Spyder 2 Pro... Why so different?

[dkperez]

I calibrated my Dell 2405fpw monitor today. I normally use my Spyder 2 Pro, but today I tried a colormunki too.

I set up the colormunki for display, specified an LCD, and selected Advanced.

It wanted to set the luminance based on ambient light, so I let it read the room. Came back with 5.67 lux, and wanted to set the display luminance to 80 cd/m2. Currently, when I tested with the crude camera meter method my monitor came up at 100 cd/m2 within 1/3 of a stop.

The monitor is already set at 30 brightness, so attempting to decrease the brightness to 80 cd/m2 wasn't possible. The best I could do was to turn the backlighting all the way down to zero, which got me 96 cd/m2 on the colormunki......

So, I let it do the rest of the calibration, and it came up with a profile....

Then I went back and specified 100 cd/m2, which is a more reasonable (in my opinion) brightness setting, and reran the brightness setting - I get 100 cd/m2 with the brightness set at 7. Reran the calibration and saved the profile (and HOPEFULLY had the monitor using it).

............

THEN I ran the calibration with my Spyder 2 Pro.

Specified gamma 2.2, temperature 6500K

When I ran the initial readings it came back at 5834K, a VERY visible difference considering the colormunki says the monitor is at 6500K. I had to turn down the red and green, and increase the blue to get me close enough to 6500K so I could run the rest of the calibration.

The two profiles don't look the same, but I can't really compare them since I can't select the colormunki profiles from the Spyder Profile Chooser. I get the message "Sorry, the calibration data in the profile colormunki_2405fpw for display Dell 2405fpw is an unexpected length. Please select a different profile.

I've been under the impression that 100 cd/m2 is a good brightness. I did some rummaging and research and it appears recommendations for a reasonably good editing room range from 90 - 120 cd/m2.  My room is controlled for extraneous light so is there a BETTER luminance I should be setting (as opposed to 100)?

Why are the values from the two tools so different? 

And HOW do I get the monitor to let me SEE the different profiles?  I'm running Windows 7 64-bit.  Where do I specify the profile to be used for the monitor?
Other than the Spyder Profile chooser, which as you can see in the error above, doesn't like the colormunki profiles.

And what does this message about "unexpected length" mean?  And how do I get rid of it so I can use profiles?

[gromit]

Why are the values from the two tools so different?

They're not precision instruments, though the Optix XR was pretty good. Use whatever you like as starting values and adjust luminance, whitepoint and black level by eye ... and hope that the profile you create bears some semblance to what the monitor delivers.

[ChasP505]

The monitor is already set at 30 brightness, so attempting to decrease the brightness to 80 cd/m2 wasn't possible. The best I could do was to turn the backlighting all the way down to zero, which got me 96 cd/m2 on the colormunki......

I'm slightly confused...  All recent Dell LCDs that I've owned or used, the "Brightness" OSD control IS the backlight adjustment.  What are you using to dim the backlight?

The simple test to identify whether the Brightness control is the backlight or not, is to open the OSD dialog and progressively lower the Brightness.  If everything dims, including the OSD panel, then that's the backlight control.  Now, if you do the same thing with the Contrast, the display will dim, but the OSD will remain bright.

[WombatHorror]

I'm slightly confused...  All recent Dell LCDs that I've owned or used, the "Brightness" OSD control IS the backlight adjustment.  What are you using to dim the backlight?

The simple test to identify whether the Brightness control is the backlight or not, is to open the OSD dialog and progressively lower the Brightness.  If everything dims, including the OSD panel, then that's the backlight control.  Now, if you do the same thing with the Contrast, the display will dim, but the OSD will remain bright.

i vaguely seem to the recall that the dell 2405 had some weird things with the control, very different from how my samsung 244t of that era worked (where brightness controlled backlight and did nothing else, the dell was different)

[ChasP505]

i vaguely seem to the recall that the dell 2405 had some weird things with the control, very different from how my samsung 244t of that era worked (where brightness controlled backlight and did nothing else, the dell was different)

The actual button on the face of the monitor controls both Brightness and Contrast, depending on the OSD menu selection.  But I also think that Contrast is disabled and not available when using a DVI connection.

[AndrewKulin]

The actual button on the face of the monitor controls both Brightness and Contrast, depending on the OSD menu selection.  But I also think that Contrast is disabled and not available when using a DVI connection.

That is correct - I have a 2405 and no ability to adjust contrast with DVI

[dkperez]

Yes, it's actually a backlight.  They just label it "brightness".....

All 5 of my LCD monitors actually use a backlight.  And they're ALL labeled "brightness".

And yes, when plugged into the DVI, you can't adjust contrast....

Anyhow, after playing for a while, going back and forth and getting things adjusted, I'm at the point
where I like the brightness (100 is good, 80 is just dark), and the printer is printing very similarly to
my monitors.....

[digitaldog]

Yes, it's actually a backlight.  They just label it "brightness".....

This is a big problem that the various display manufacturers have heaved upon us. There is only one physical control over a CCFL LCD, the intensity of the Fluorescent back light. What they call this on the OSD varies. How granular the controls are differ. Its why I prefer "smart monitors" like Eizo and NEC SpectraView that do all this adjustment (and more) in the panel based on target calibration values you specify without having to touch any such OSD controls.