Originally Posted by decu
My monitor shows allot of tonal values, and this problem appears 2-3 weeks ago..
Didn't find so much info about your monitor, but it's a $1500 monitor. All monitors below $3000 are not professional monitors and tends to show no more than 256 tonal values per channel, meaning that these monitors are not able to show a full range of tonal values above 256 per color or gray scales. Also, all these monitors are just 8 bits of depth and also below the sRGB gamut and also, all these technical stuff represented by 72 pixels per inch, so we can say we just see quite less than a 25% of the total information held by any digital image.
These are professional monitors 16 bits made (for color and gray scale images) with a gamut a bit over Adobe RGB 1998 and they cost an eye of the face: http://www.eizo.com/global/
but still 72 PPI.