I'm really impressed with this lens. I have the well respected Minolta 28-135 zoom that comes close to equalling the 24-70 zeiss and this lens beats both of them in its range.

I posted full size pics at f3.4 and f8 for each focal length designated on the lens at: http://www.pbase.com/masimo/cyz_3570_conversion

I still have a 28-85 zoom I may convert but will go a different route with that one. This is a hollowed out m42 adapter that is shaved down to where you can nearly cut yourself on the flange even that wasn't enough though and I finally had to mill down the lowest step on the CYZ flange to get the M42 adapter to mate tightly to the CYZ. No room to countersink so epoxying the flange on is the only real solution. The lens was dropped last summer from the roof of the car at @25mph but aside from being a little loose continues to work its magic just fine.

Next lens will be converted by making a blade ring just like the one on the contax lenses but a little thicker and conversion will be removing three screws and the ring then fitting the new ring and replacing the screws.

Have a look at the pics. There are two of some of them at different exposures so you can see the corners.

None of the shots are sharpened or noise reduced at all. Shot raw and converted in Raw Developer with a little exposure adjustment and nothing more.