I've got an old Quantaray 135/2.8 in my desk at work that I use for new employee pictures for our newsletters, etc. This came with some odds and ends that I had to accept to buy a package of things from eBay many years back.. The lens is absolutely amazing. I'm sure it's a fluke but its color and clarity are first rate. Back in the 70's, I had a Quantaray 24/2.8 that also was very good and I was recently looking at some old Kodachromes that reminded me of the solid performance of that old glass. Vivitar stuff is certainly a mixed bag and I'm sure the Quantarays are chancy, too. The 2 I've used were excellent but considering the market they were aimed at, I wouldn't expect too much but you might be pleasantly surprised as I was in my limited sampling. Many years back, a friend had a Series 1 80-210 that surprised me with its results and the one that I bought wasn't nearly as good and was quickly sold. The only good thing about the lens is that it kept me sworn off zooms for a number of years after that! I've currently got a 35-85 Series 1 that I had read some good things about but frankly, my example is nothing very special optically and I can't recall the last time it was even on a camera.