Census index off very poor image - how?

[tn17]

Bit of a random question, but I've been looking at the 1841 for Ilminster (HO107/929/20), and the writing in the images is so feint it is practically illegible.

However, a very well-known family history site has a pretty clear index. Sure, it has plenty of typos, but it was enough for me to find two families in Ilminster. My question is, if the images are so poor, how could they do it?

Does it indicate that better quality images might be available somewhere? I only ask because both families seem to have a couple of extra hangers-on that could be extra relatives, and I'd love to have a look at a better image and see if I could make out the names correctly.

[stanmapstone]

A major problem with the 1841 census is that it was written in pencil rather than pen. This has resulted in many faded pages which have proved unreadable on microfilm. To rectify this problem Ancestry has gone back to the original census manuscripts at The National Archives (TNA) and digitised many of these hard-to-read pages.

http://search.ancestry.co.uk/search/db.aspx?dbid=8978

Stan

[tn17]

Thanks Stan