I like to use diopters with my 5050.
The super macro specifies a focal length of 59mm (equiv to 35mm), has a 
very short lens to subject distance of 1 inch and has barrel distortion.
I have a Hoya doublet +10 diopter which gives around 1.4 times the 
magnification of the "super macro" at a lens to subject distance of
2 3/8 inches with no distortion. Being a doublet, it has excellent 
quality.

Here's a comparison picture.
http://tinyurl.com/7voc

Here's a picture showing the super macro compared to +4 and +2 single 
element diopters. That combination equals the magnification of the SM 
with a lens to subject distance of 3.2"
http://tinyurl.com/6qjb

-- 
Charlie Dilks
Newark, DE  USA