First Blog Image / Same size on Post & Blog List

Hi Support

Is there a way to get the first blog image the same size on the blog post and on the blog list.

Here is an e.g.:

http://finalbug.net/blog/entry/403-making-a-viral-video-with-a-bezillion-views

The original size is 800 pixels times Y.
i.e. I am talking about X & Y co-ordinates.

Important is the width and the ratio of the width to the height!!!

thanks

Paul