If your display is an LCD, I'm inclined to really doubt your assessment that your display's "native gamma" is 1.9. How did you determine that? Most native gammas of LCDs are 2.2-2.3 unless something else might be going on with your display pipeline..
Well I used Spyder 3 Elite to measures TRC using one of their tests. This is the result.
...unless I misinterpreted something as you seems to suspect I assumed it's Gamma 1.9. Since even out of the box it was quite bright.
EDIT: I just remembered to check the help section for the Spyder and here is what it says for the test.
"The Tone Response test measures the response (gamma) of the monitor and plots a graph comparing the measured tone response to standard gamma curves. If your monitor has a control for selecting different gamma settings, you can measure all of the different settings and then find out what is the actual gamma that the control sets. This helps you to select the best setting of such a control before calibration.
For example, a monitor may have a setting in its On Screen Display (OSD) for Gamma with choices "Gamma 1" and "Gamma 2". You can run the Tone Response test and measure the display in both of these settings. When the results are plotted you may find that "Gamma 1" is actually Gamma 2.1 and "Gamma 2" is actually Gamma 1.9. If you were then going to calibrate the monitor to Gamma 2.2 you would know that setting this control to "Gamma 1" would be the best choice since it is closer to the desired 2.2 target value."
This monitor is an older one and does not have an option to set gamma from OSD
Lenovo L220XWC 22-inch LCD Monitor
Panel Technology: S-PVA
Panel Manufacturer: Samsung
Glossy panel: no
Screen Size: 22,0 Zoll (inch)
Pixel Error Class: 2
Pixel Pitch: 0.246 mm
Response Time (rise + fall): -
Response Time (grey-to-grey): 6 ms
Native Resolution: 1920 x 1200
Brightness: 325 cd/qm
Contrast Ratio: 1200:1
Dynamic Contrast: -
Viewing Angle vertical (10:1): 178°
Viewing Angle horizontal (10:1): 178°
Viewing Angle vertical (5:1): -
Viewing Angle horizontal (5:1): -
Color depth: 16,70 Mio.
Net dimensions (WxHxD): -
Housing Color: black
Input Video Signal: D-Sub (analog)
Inputs (quantity): 2
S-Video Input: no
Base (swiveling): yes
Base (height adjustment): yes
Display slanting: yes
Integrated Speakers: no
Weight: 7,2 kg
It doesn't mention gamma. I assume from the messured gamma using Spyder 3 that is the native gamma. Was I wrong?
GPU nVidia GeForce 8800 GT
OS: Windows 7 x64