Decent wide-angle adapter

[Zensteve]

It will be a while before I get an actual wide angle lens, so figured I might fudge it meanwhile by adding a wide-angle adapter to the front of a fixed 28mm lens. (52mm thread)

Looking to widen the angle of the 28mm on the crop-sensor T2i, to beat the 18mm on the 18-55 kit lens

Is there a decent (and cheapish) wide-angle adapter brand/model that doesn't end up with huge vignetting or barrel distortion?

 

[Ernest Worthing]

I've never used one so cant be of much help but have you looked into renting the focal length you would like from borrowlenses or a similar site?

 

[IndieBudget]

I have never found a decent one..always soft focus issues and aberrations. Of course I always used the cheapo WA adapters meself