On a 1024x768 screen, this leaves a big gap on the right side, or do you have it set for 800x600 viewers?
No matter what size photo, it comes up 500 pixel width on the screen
Example: here is an 800x600 photo. Notice the big gap on the right side at 1024x768. Why can't we use that space?
Also notice it has distorted the text to be unreadable.
On the redfish tide post, I had to manually resize the photo to 500 width to keep the text readable (a real pain)

