The specifications can be found at this link http://www.samsung.com/uk/consumer/...
. Micro Dimming is an LED backlight format.
Micro Dimming Plus is the name given to our micro dimming scheme for edge lit LED TVs; essentially the TV has backlights originating from each edge of screen. Each group of LEDs that light up the screen are split up into zones. When the TV wishes to darken a picture, the zone is tweaked; eg, if a zone consists of 18 LEDs, all 18 would be dimmed, brightened, etc.
This would all be managed by software, which analyses the image on screen. The difference between Micro Dimming and Micro Dimming Plus would be the number of zones and LEDs in the backlight. more zones would allow for finer control of the backlight for example.
The difference will be most noticeable when watching dark media, like movies etc.