Extreme macro with Canon 30D

Just wondering if anyone has experimented with the Diopters with the Canon macro lens?

I have both the 60mm macro and the 100mm macro. The 60 focus' faster then the 100, so I was curious as to know if anyone has done this.

Is the equivalent of a 100mm & +2 diopter a 60mm & +5 diopter?

a diopter works by making the lens focus closer. The 60mm already focusses at 8 or 9 cm from the front of the lens. (thats around 3,5 inch) Some of that is taken up by the port, the other bit of working distance you will need.

I have a 100mm with 250D (+4) and 500D (+2) diopters, but havent tried it yet underwater. with the +4 the image is around 13 mm wide (but the port magnification will decrease that underwater as well, increasing magnification).

you might wanne give telecopnverters a try. they keep the working distance and increase magnification. i am very happy with my 1,5 kenko and the 100mm on the 30D.

another good alternative to diopters are wetdiopters. (woodys, inon ucl, macromate ...) specially when using with lenses like the 60mm ... because as gerard said, a 60mm gets close to useless under water, when using with a diopter, because you have to be toooooo close to the object. but with a wetlens you alway have the choice to take it off under water and use it where it is possible.

greets, serge