I went back today and compared a scan I did of an 1841 UK census entry with the entry at Ancestry.com. The different was outstanding. I remember spending HOURS upon HOURS looking for the family originally when barely half the census page could be read. The images at Ancestry.com were enhanced and are a significant improvement over what I got from the microfilm.
The images are not the same size, but there is no doubt which one is better.
Take a look:
http://www.rootdig.com/framecensus/1841.html
Michael