I hate mine. I have a the same Ricoh version (with the pin removed), and it's the softest, most worthless low-resolution piece of crap I've ever used. At f2.8 don't even think about rotating that front element, unless you want blur, blur, and more blur. If you don't, it has a minimum focusing distance of about a mile and a half, and it's still not even remotely sharp. There's still some glow at f2.8, no matter what you do. If you really stop down it can be marginally useful, but this is a $20 lens and you get what you pay for.
Here are some samples.
Rotated one click. Used flash and 1/125 shutter speed to eliminate possibility of blur. ISO400. Contrast adjusted, that's about it though, no sharpening.
Here's a real nice showing of how craptacular this lens is at f2.8 with the front element rotated into the macro zone. This is straight out of the camera, without any edits. Trust me, this is correctly focused.
And here's the same photo with a bit of post processing work. (Still no sharpening though)
What's even worse, the uncorrected aberrations completely screw up the focusing engine. It "dink-dinks" for catch-in focus when it's not even REMOTELY close to focused. The only way to focus the lens is using the screen. This lens is junk.
Charles.