I'd like just a few posts on the front page but many more on the category pages

Apologies if this is not the right place for this, I couldn't figure out where else it might go.

In fact it might not even be an Athualpa issue. I tried over at WP codex, but found no joy.

I want to have, say, 5 posts on the front page. I like full posts (not excerpts) on the front page. Many of my posts are image heavy and so if I have many full posts the load time goes up.

But on my category pages I'm OK with using excerpts and thus I want to be able to show up to 40 excerpts on the category pages.

I know about using the "Reading" tab in WP Settings. But, of course, that applies to front page and category pages at the same time. I am using "10" at the moment but I think that's too many for the front page and not enough for the category pages. www.pooplist.net is the site

Any ideas?