Originally Posted by sikclown
When you have a picture open go to edit then Effects and then long press on one of the filters until Custom appears at the bottom. ... Haven't found a way to mess with the filters at picture taking time though.
Ahhhh, hidden under a long press. Figures.
Not to say that said device doesn't exist, but I don't think I've ever seen a stock camera application that you can personally edit/customize the live filters on the fly (besides the optional slider bar needed for some effects)...