Originally Posted by ulysses
The Vivitar is no dog. It's just not up to the quality of the older Series 1 models. Personally, I believe that just about any modern day lens (within the last 30 years or so) is very capable of delivering very fine results. There are really very few truly hideous lenses out there. Just earlier today, I was perusing my huge file of AP (Amateur Photographer) test results from past and more present testing. I've always found AP testing to be rather stringent & consistent. Even AP had trouble finding fault with some of the lenses that we consider to be "dogs." Of course, they can't test for long term durability, which is also a factor to consider when purchasing new glass.
I personally believe, and keep in mind when reading lens reviews and opinions by other's, that most lens faults are "operator error" and caused by poor and improper technique (camera shake, crappy filters, funky lighting, etc). I have slides, negatives and prints made from 30 year old lenses that are extremely sharp. I've never had an editor, publisher or print buyer, ask me what lens was used for making said snap. I have some drum scanned slides shot with an older Vivitar Series 1, 28-90, that people swear was shot on a medium format rig, until I tell them otherwise. The scans and large prints are very impressive.
The bottom line is, if you have a lens that satisfies you with it's results, you've got a good lens.