What answer??? The pictures you showed are not taken from playing the game! They were delivered by the game developers prior to launch! Have you seen the actual play screens on numerous sites?
The fact that AO3 has no HDR support on ATi cards prior to the x1800 Is not becuase of lack of technology or performance by Ati, is because the developers of the game choose not to support it! Have you seen a screen shot of HL2: Lost Coast? They have HDR on ATI cards!!! and with SM2.1!!!
Here is what HDR looks like on an ATI X850XT PE.
http://pablovillegas.com/varios/HL2/d2_lostcoast0000.jpg
http://pablovillegas.com/varios/HL2/d2_lostcoast0001.jpg
http://pablovillegas.com/varios/HL2/d2_lostcoast0010.jpgI bought this card just a week ago, and it was the best decision I could've made, it's the best AGP card, I didn't wanted to spend extra on a new motherboard, processor, and doing a clean install, that's why I choose this card, not because I love ATi or hate Nvidia, If I had a Pci-E port I'll probably should have bought a 7800 GTX. But I don't have one.
Look, I make a living on lighting and shooting things, so don't say that sharp shadows from the sun are not real. What is unreal is having a soft filter on everything, and that's the effect of HDR, it works for some games, but not for all of them, in the case on AO3 I think it works, but it's to much. I would've used a mmuch lighter effect. But that's just personal taste. I preffer the look of HDR on HL2:Lost Coast