I need help in building a LCD flicker meter using photodiode and a current amplifier. The aim is measure the LCD pixels's flicker that can be detected by human eye so as to have a representation as electrical signal. This is to use it in cases where it's hard to judge if there is a flicker noise present or not, or if it happens only once in a while. There is a big range of photodiodes available with frequencies up to GHz for optical communication. LCD refresh rate is 60Hz (so assuming this fact LCD flicker would also be <60Hz or assume <120Hz to be detected by human eye). Since flicker will appear as distortion (or may be RGB pixels in off state), I assume some filtering will be involved.. Any ideas?