Hmmmm, curious. I have the XSi too and after perusing your album I feel like I can pick out the pics that were taken by the XSi because of the color profile. Is it me or does it appear that the camera is red-sensitive? I feel like I've seen similar color biases in my own landscape photos. I know different cameras use different sensors that have different color sensitivities. So I wonder if the Canon XSi is by nature, this way... and noticeably so.
