Anyone familiar with the Sigma 100-300 f/4.5-6.7? (pics inside)

[EricT]

I just picked up a Sigma 100-300 f/4.5-6.7 at a garage sale. It was only $40, so I figured I couldn't go wrong with it. I've tried to find some information here about this lens, but without luck.
Does anyone else have this lens? How does it compare to e.g. the 70-300s and the Pentax 55-300?
From my brief experience with it, it's pretty decent. Obviously the build quality could be better, and the lens could be faster, but it's a lot of fun to use.
I didn't really think I'd enjoy using a telezoom, but after a day in the park I'll have to reconsider that! Here are some pictures:
1/750, f8 @ 300mm


1/1000, f8 @ 170mm (slightly cropped)


1/1500, f8 @ 108


I will do a more thorough sharpness test on a tripod and post a review in the review section of the forum when I have the time.

[timbo13]

I have this lens (I paid $50 for mine as I recall) and I like it. I use it mostly
for photographing my sons playing sports and that sort of thing. I like the
image quality better when it's stopped down to f8 or so, and it can be a
little soft out at the 300mm end in my opinion. From what I've seen posted
here on PentaxForums, the Pentax 55-300 is a better lens, someday when
I can afford it I might get one

[EricT]

Originally Posted by timbo13

I have this lens (I paid $50 for mine as I recall) and I like it. I use it mostly
for photographing my sons playing sports and that sort of thing. I like the
image quality better when it's stopped down to f8 or so, and it can be a
little soft out at the 300mm end in my opinion. From what I've seen posted
here on PentaxForums, the Pentax 55-300 is a better lens, someday when
I can afford it I might get one

Yeah, that's my experience as well, that it's best around f8. That's usually a good idea anyways when photographing moving subjects to keep the depth of field
large enough. The first shot I posted is at 300, and it's pretty sharp for a handheld shot IMO. It's really hard to keep the camera steady at those focal lengths. I'll have to do a tripod test to see how sharp it really is.

The 55-300 gives you a bit more speed (the AF speed is probably similar, though), and quick-shift would be very nice, but at about 6 times more, I don't know...

[egordon99]

I bought that lens on clearance at Ritz for ~$60. It was my first 300mm lens, and it did ok. Contrast was a bit low from what I remember, I returned it after about a week since I got a good deal on a used Pentax FA 100-300mm which was f/5.6 at 300mm instead of f/6.7

I'd say $50 for a telephoto zoom that goes out to 300mm is a decent deal.