Canon 5D Mark II First Look-Photos and Review
After the somewhat disappointing performance of the Canon 50D skepticism runs high. The 15.1MP 50D was expected to take the resolution crown in the APS-C market, but instead it basically tied with the 12MP D300/D90/Sony A700. This is certainly not a poor performance by any means, but it did not match Canon's marketing claims, and it brought into question Canon's claims about the performance of their new sensors.
The new camera has a feature called "Higlight Tone Priority", which seems to be turned on when it ships. If that was turned on, the noise levels presented are actually worse than they could be:
HTP choses a lower ISO setting and then underexposes to frame. It later applies a curve to increase exposure again but through that process increases noise since dark areas are being boosted!