One of my photo students brought this wide-angle lens to class and I tried it. I was impressed enough with the few shots I took that I ordered my own lens from Amazon.

I tested mine on a Nikon digital SLR with an 18-55mm zoom lens and on a Canon G5 compact digital camera with a 35mm to 140mm zoom lens (35mm equiv). On the Nikon, this wide-angle lens expanded the wide-angle coverage of the 18mm focal length to something wider than 14mm. On the Canon, this wide-angle lens expanded the wide-angle coverage of the 35mm focal length to slightly wider than 28mm. The macro portion of this lens was similar in performance to my +10 diopter supplemental close-up lens (also called a close-up filter by some).

After additional shots and tests, I can say without reservation--this lens produces decent quality wide-angle images and the macro portion produces decent quality close-up images. Yes, there is some darkening of the corners of the image (vignetting) and there is significant curving of straight lines (barreling) and there is some loss of detail on the edges. However, this lens is a great bargain and I will highly recommend it to future students.