20" Aluminum iMac Screen ...

[sammy2066]

Are the newer batches of the 20" Aluminum iMac shipping with 24bit screens? I ask because I was talking to Apple Support the other day, and the guy said I could return my 20" iMac and the new one which I would get would not have any issues with color banding.

Can someone confirm 24bit screens on 20" version?

Cheers,
Sam

 

[tegg]

My new 20" iMac arrived last Friday (shipped Sept 26th). I can't confirm if it has a 24bit panel in it, but running LCDTest doesn't show any of the lines/bands that my MacBook shows with the same gradient tests. Maybe they have just improved the dithering algorithm, but the gradients are nice and smooth.

It's definitely still a TN panel though (there is a big variation in brightness if you change the vertical viewing angle).

 

[Kaspers]

It seems there are two types of LCD displays in the current iMac line -- twisted nematic (TN) in the 20-inch models, while the 24-inch uses a Super Patterned Vertical Alignment (S-PVA). The TN panel typically displays 6-bits per pixel; the S-PVA, 8-bit. Three colors are involved in generating a point of white light, so 3 x 6 is 18-bit color, while 3 x 8 is 24-bit. However, the TN uses a technique called dithering to trick the eye into thinking it's seeing 8-bit pixels.

Hope this helps .

 

[DemNoir]

My new 20" iMac arrived last Friday (shipped Sept 26th). I can't confirm if it has a 24bit panel in it, but running LCDTest doesn't show any of the lines/bands that my MacBook shows with the same gradient tests. Maybe they have just improved the dithering algorithm, but the gradients are nice and smooth.

It's definitely still a TN panel though (there is a big variation in brightness if you change the vertical viewing angle).

Does it still have the color shift from top to bottom? If you display a colored sticky and slide it form top to bottom does the color change?

 

[sammy2066]

Thanks for the replies guys! So that means it still ships with a TN panel. So there's no point in returning it.

 

[RevToTheRedline]

Hope this helps .

All well except the 24" is an LG.Philips S-IPS not a PVA. Same difference though, both 8-bit