From: Pittsburgh, PA
We do not sharpen original images (we are going to test this and see if we should be). We do sharpen thumbnails when the reduction in size is more than 10%. To keep your original images unmodified, resize your images to a max width/height of 800 pixels (width <= 800, height <=800) - in this case, we do not resize the sent image.
Get out of the vacuum and express yourself!