Soft release buttons aka "softies" are buttons which create a larger, more protuberant shutter release button on your camera. On Leica rangefinder cameras, there is a threaded hole in the shutter release button for the cable release, and you screw the soft release button into that cable release thread.
The purpose of the soft release button is to make it smoother and more comfortable to trigger the shutter release and thereby improve the sharpness of images taken at slow shutter speeds. The buttons come in a variety of designs with either concave or convex designs.
Since our Micro 4/3 camera shutter release buttons lack a cable release thread, there is no way to use traditional soft release buttons made for Leica cameras. A Korean company called Gariz makes stick-on soft release buttons which serve the same purpose, and after learning about these from
one of our members, I decided to give them a try.
Gariz buttons come in either convex or concave designs. The convex buttons come in sets of red/black, and the concave in silver/gold. I chose the convex design since it allows me to comfortably hook my finger around the button. Also, I like the red

.
Here's what they look like in the packaging (photo from
http://global.rakuten.com):
My E-P3 with the red Gariz soft release button (also
Aki-Asahi skin and
Gariz leather half case):
Next to the E-PM1:
The soft release changes the way I shoot these cameras, using the inside of my first knuckle instead of the finger tip:
The soft release improves comfort and seems to improve my ability to hold the camera steady at slow shutter speeds. $12 well spent!
I bought my soft release buttons from
Pricejin on Ebay. The free economy shipping took about 3 weeks.
[Thanks
joseetan]