> I came across it because at one point, there was a vogue for using these lenses with an adaptor on Micro 4/3 cameras. The idea was that you'd just dropped get

> I came across it because at one point, there was a vogue for using these lenses with an adaptor on Micro 4/3 cameras. The idea was that you'd just dropped getting on for a thousand pounds on a camera body, so couldn't afford a lens, so you'd buy some thirty quid lens from China and use that. Needless to say, it didn't take people long to realise that was really stupid. I think people were also attracted to adapting those lenses because there are readily available CCTV and machine-vision lenses which are, compared to typical photographic lenses, extremely fast (like f/1.0 and lower). This is for applications like security cameras which need to be able to work in dim lighting conditions, or machine vision applications that require a very short shutter speed. Of course what the Micro 4/3 crowd eventually came to realize is that in order to achieve a fast lens at a modest price point, those lenses trade off other qualities like resolution and distortion, which are less important in their intended applications, but seriously compromise the lens for photography.