So lets start. Here is a photo from each combination. Both at the maximum aperture of each lens (I will only compare them at max aperture). With the Sigma lens the minimum focus distance is much longer than the Kamlan which limit the amount of background blur you can achieve with this subject. Also, I was shooting indoor at night hand held and had to bump the ISO to 1600 with the Canon to achieve blur free image. Whereas with the Olympus I was using ISO 400 because it has in body image stabilization (IBIS) and was able to shoot blur free image at 1/15s. In these two images I was trying to frame them the same but actually the Kamlan is a tighter crop.
|Canon EOS 6D, Sigma 85mm F1.4 @ F1.4, ISO 1600, 1/80s|
|Olympus OMD EM10, Kamlan 50mm F1.1 @ F1.1, ISO 400, 1/15s|
|Olympus OMD EM10, Kamlan 50mm F1.1 @ F1.1, ISO 400, 1/15s at minimum focus distance|
|Canon EOS 6D with Sigma 85mm F1.4 100% crop|
|Olympus OM-D EM10 with Kamlan 50mm F1.1 100% crop|
So in conclusion, Kamlan can achieve very good level of background blur although the sharpness is not at the same level. With IBIS, image noise can be lower than full frame (if the lens do not have IS).
At the end of the day the Kamlan 50mm F1.1 is not as sharp but fun still the same. I will carry on using it for day to day non critical photos. Sharpness is not the be all and end all of photography. I would highly recommend the Kamlan lens.