Next test was seeing the difference between the two lenses using flash. Both images were taken with the 5DmkIII, ISO 50, f/4.0 1/320 a second.
The MkI does a good job, no doubt, but when compared to the MkII… The differences are clearly visible.
Softening of some of the details. Visible definition loss in the texture of the twine and fabric. The surface of the bells have lost some of their texture. There also appears to be color bleeding in the red areas into the yellow.
MkII – noticeable differences are the sharpness in the reflection in the lower of the two red rimmed mirrors. Also, the metal bells in this image are sharper. And the colors are more accurate, without blurring/bleeding.
There’s no doubt that the MkII is a big improvement over the MkI. The improvements are clear when images are viewed side by side.