Sigma 50-150mm?

I really like what this lens looks like on paper,but also have herd bad stories about front and back focus.Anyway,I have a chance to pick up a used one locally and the seller has agreed to let me shoot as many pics as I like and take a day to make up my mind.Is there anything specifically I should be looking for?Should I bring a tripod and a focus chart and do a quick front back focus check?Any help would be appreciated with specific things to look for in this lens.
Dave

Sigma is coming out with a new version of this lens with os ( sigma's is ). It is supposed to be of very high quality.

Yes,but from what I understand it will be quite large and one of the reasons I like this lens is it's compact size for a f2.8 zoom.

The main issue that was reported with this lens was front focus at short distances (say, less than 2m), especially at 150mm and f/2.8. I had 2 copies of the Mk I version of the lens that did just that. There were reports of the same issue on the Mk II version of the lens but I've not owned that, so can't verify it. If you plan to do some focus tests, make sure you do it in decent (preferably outdoor) lighting - focus tests often seem to give odd results in normal indoor lighting. If it were me, I'd just go outside and shoot some things at around 1.5m, and at longer, distance. If they look fairly sharp, especially at 150mm f/2.8, with no big difference between short distance and normal distance, it's probably fine.

Bear in mind that, even if you do see this problem, it may not be an issue for you, depending on how you're likely to use it. Besides the focus issues, it was a superb lens.

Thanks gcogger,should I be concerned if its a I or a II version?I have a 7d,so I assume I can adjust the focus issue if there is one,I would be mainly concerned about resale value.

I've had a version I Sigma 50-150mm f/2.8 for around four years. I can say it's one of the nicest zooms I've used/owned in 30 years of photography.

The 50-150mm hasn't been smooth sailing though. On my 20D it's as sharp as a tack even at full aperture. On my 50D it needed some AF Micro adjustment to get the best out of it.. All is good now

dfarina wrote in post #13063570
Thanks gcogger,should I be concerned if its a I or a II version?I have a 7d,so I assume I can adjust the focus issue if there is one,I would be mainly concerned about resale value.

On the lenses I hadd, the micro adjust on-camera would not have helped as they were fine at most distances but front-focusing at short distance. The camera can only make one adjustment for the lens. I wouldn't worry too much about Mk I or Mk II as I believe they're of very similar quality.

I'll echo what Yogestee said... it's one of the best lenses I've used and owned. I use it on a 50D, and it took a small amount of microfocus adjust, but now that I have that out of the way, it's amazing. My favorite lens, hands down. If you have a chance to get it at a decent price and want to take portrait shots as part of your work, BUY IT.

I've had the same 50-150mm since they first came out . Love it .

I have owned this lens for many years and use it mainly for Basketball in high school gyms.
Have not had any trouble with it, did have to use micro adjustment with my 7D

Thanks for all the feedback,I am going to have a look at it today,snap a few pics and have a look at them before I decide.If it focuses fine and is sharp I will pick it up tomorrow.

Well......I decided to pass on the lens,I took a few close pics at f/2.8 and it was either a little out of focus or just plane too soft for my liking.As well I brought my 15-85mm and compared a few pics at 85mm f/5.6 and my 15-85 looked sharper.What also turned me off was the 50% out of focus shots I got(took about 30 pics)my trusty 15-85 has a much higher success rate.It was sunny outside and the shutter speed was very fast,1000 or faster.Don't want to make it sound like this lens was terrible,maybe I am being a little critical,but it wasn't good enough for me to part with my $$.

I think I am going to get a Canon 100mm f2 prime,that is the focal range I am looking for and I also have a 1.4 tc if I need an extra reach.

I need 30 posts to create a new post in the wanted section...this is #29.

And here is #30!!!