I've been trying to get my hands on a fast prime lens of between 85mm & 120mm for my OM system for portrait work with no luck. I do have a 50mm f1.8 and a 2x converter. I know that using the converter will lose me 2 stops of light which isn't a big problem but will it also lose me 2 stops aperture? I don't think it should. If anything I think I should actually get a shallower depth of field as I will be focusing at a greater distance and, if I remember correctly, DOF is affected by aperture, distance to subject & focal length of lens. Is this correct or am I doing dodgy science?