LCD ppi vs brightness

[sasiskas]

Hi guys, some days ago I was arguing with a friend whether higher ppi causes lower brightness on LCD panels.
I remember Linus has made a comment about this issue in the past, but I can't really find that video.

My opinion is that because the LCDs use baklight, the higher the density the harder it is for the light to pass through the pixels.

What is your opinion? Can you find that video? or any other source that can prove the relation between ppi and brightness so I could shove it up in my friends face

[ZetZet]

It's mostly the case of balancing power, more pixels need more power more brightness needs more power.

[sasiskas]

yes, but in the case of a smartphone a higher density should cause lower brightness or lower battery performance. right?

[Glenwing]

Yes, higher density results in less transmittance, since each subpixel requires a TFT to drive it which blocks a portion of the backlight. Usually this doesn't result in lower perceived brightness (because brightness is variable; if the brightness is lowered, they just increase the brightness until it looks the same again), it just results in higher power consumption because more power to the backlight is required to compensate for the lower transmittance of the pixels.