Originally posted by seventysixersfan I was waiting for you to weigh in on this thread, Edgar! You are the best promoter of the virtues of this lens! (Certainly, it influenced my decision to get one) Thanks for your observations and opinions--I wholeheartedly agree!
I think one of the reasons this lens was discontinued was that it initially received some bad press right out of the gate, so a lot of people were instantly turned off. When I discovered the lens, the first thing I did was do a Google search for reviews. To this day, if you do a search for
Sigma 50-150mm HSM II review the first result that comes up is still the bad review from The-Digital-Picture.com, which is basically a "hit piece" on the lens.
They were reviewing the lens in Canon mount, and the three copies they tried all severely front-focused on their camera. There had obviously been some kind of glitch in the initial calibration for the Canon mounts, at least in an early batch of the lenses. But instead of contacting Sigma about the issue or calibrating the lens or retesting the lens a little later down the road, they just went forward with the review and concluded that the lens was basically a bad buy. (I suppose this was in the days before most camera bodies had options to fine-tune the autofocus of lenses.) They also claimed that the lens was soft, which is in stark contradiction to most of the other professional reviews I have found.
So when I discovered how great this lens really is, and how wrong that initial review was, I kind of made it a mission to let people know what a gem the 50-150mm really was. This was before the lens was tragically discontinued. And I'm not alone, since most user reviews of the lens, regardless of mount, praise it for its sharpness, image quality, autofocus performance, and handling. It's just too bad that Sigma didn't do more to promote the lens.
Someone else suggested that perhaps these "refurbished" lenses are actually versions that were made in other mounts but were never sold, and that Sigma converted them to Pentax mount. I wouldn't be surprised if that was the case. After that bad review, you'd have to be crazy to buy the lens for your Canon or Nikon. So I expect there probably were a lot of Canon and Nikon versions that were never sold. And now that IS is prevalent in most Canon and Nikon telephotos, they probably would have had to basically give them away to sell these unstablized lenses to Canon and Nikon users.