595 Shift Register Not Working Properly
The dimming problem was found to be the shift register IC not connected to Ground (dumb me). 

However, there is still problem with LED's on and off pattern. Sometimes two LEDs turn on at the same time and all previous LEDS turning off before the last or second last LED is turned on. It turns out Pin 10 (SRCLR Bar) needs to be pulled to high to solve that pattern discrepancy.