[crazy_wooo]

If there is 黑角 when I am using c mount lens in m4/3 cam,
can I use a c mount extension tube to fix this problem??

any other problem will be appeared if I use the extension tube?

[crazy_wooo]

Who know how to fix the "black corner" problem?? Pls help!!

[cambug]

The appearance of dark corners is the result of insufficient image circle size, which is one of the lens design factors, somewhat fixed once the lens is made. The image circle would be bigger if the lens is extended out, like macro photography set up, however it would be back to square one once it is focused to infinity. It may be possible to slightly increase the image circle if the limitation is caused by mechanical blocking, in this case shaving some mechanical parts may help. It has to be investigated on individual basis. Good Luck.