I have a question about lens converters, but not only in relation to m4/3. 4/3 lens have all sizes of filter diameter thread, but the same sensor size. For 17mmOly pancake I chose somthing like this - a 37mm lens adaptor. A cheap one. Here you can see results: I don't care about distortion, but would like to eliminate gradual lack of sharpness off the centre. It seems to add to background blur as you can see above. I wonder whether it just optical quality of this gadget, or its image format, as results remind me such lens, which are usually made for 1/3" sensor. Should I the get a stepup ring and screw on a larger than 37mm converter, ex. which could have larger image format, ex. this one?