Online calibration/tests?

[goodCat]

Hey guys, I just bought an HP LP2465, S-PVA panel. I am really happy with it so far, except how it handles grey and grey gradients. For example (254,254,254) is waaaay darker than it should be. This causes also some banding. I think I saw a website here on hardforum mentioned quite a few times. Can you please help me? I am a total noob when it comes to calibrating.

thanks!

 

[Ryom]

http://www.lagom.nl/lcd-test/index.php

 

[goodCat]

thanks, I tweaked it a bit (contrast, gamma) and I managed to improve it, but I can still see some banding on vertical gradients, especially from black to white.