So ran some tests . Major improvement on the ZM 35 as Fred has posted some results of that and my tests prove the same excellent improvement with the OptimaSigma .5
The ZM 25 with the Proxar 1m and the Hoya 1m also big improvements as well. Im going to go out and test the Hoya vs Proxar just to be sure at infinity the Hoya was better but on Big Bronco The Hoya on the right side was slightly better but the left side for the Hoya was slightly worse. Mixed bag but Im leaning more on the infinity shots and I would say the Hoya.
Bottom line either way your going to be fine as in most cases your not wide open anyway but the improvements here are outstanding than just the native lens.
