The 1/200 figure you have is for the 58mm lens on the Minolta 2X L MD/AF adapter.
If you look at the full size thumb previous to the Haoda adapter thumb you will see that the 58mm alone without adapter yielded an exposure of 1/1000th which is more than 1 stop of light loss. The light loss does depend on the lens used, with high performance large, element lenses suffering the most.
