way better than the kit lens that came with my camera
585010
I'm mixed about this lens.  The colors it captures are vibrant and when in focus it's fairly sharp; way, way better than the kit lens that came with my camera.  Unfortunately on my Panasonic DMC-G5, the auto-focus is pretty terrible.  It hunts, it's loud and nearly inaccurate each time, especially for action shots.  In low-light auto-focus is practically useless.  Switch to manual focus however and it's a really solid lens, capable of producing some very nice shots, which need very little post processing.  That's a pretty big statement, considering my camera is near the bottom of the micro four thirds line-up.

The other strange thing about this lens is the area of coverage.  It's narrow for wide angle and wide for narrow angles; it's not quite square, but it's close.  A strange photo; almost like the old flash-cube cameras of old.

I'm mixed.  For the right application, it's a great lens.  For a training lens, it's a great lens.  For general purpose, probably not the best choice.  The price is fantastic though, no denying that.
2611329
I was about to purchase a fish eye lens from pentax when I came across this lens. I figured for the price lets see what it does and wow. I never had a use for my kit 18-55lens and now i love it. This product is well worth the cost. I am very happy with it
1198094
Bought this during the Amazon lightning deals at a great price (really only reason I bought it) to replace our 75-300 that we got free with our camera.  I will say, that just after a couple sporting events, it is already much better than the 75-300 and the image stabilization does help. We ran through the first couple set of indoor basketball and soccer pictures and they turned out much better than the 75-300. We tended to produce images that had a haze with the 75-300 and have not seen that same issue on this lens.

Until we can afford an L series, we are very happy with this purchase and would recommend for someone starting in photography or are just looking to take pics of their kids events.
2676293
This was the first lens I purchased after picking up a t2i and I'm extremely pleased with it. The picture quality is excellent, it's not that heavy, and it just feels like it's built well. Definitely better than the kit lens that came with the t2i. Being able to shoot at 2.8 throughout the entire range and the optical image stabilization were the two deciding factors for me. I did quite a bit of research before I bought it and haven't regreted the choice for a second. I would definitely highly recommend it to anyone.
702336
I started photography and wanted a fast lens that gave good image quality. I didn't want to spend the money for Nikon, So this was an alternative. It does amazing work. Really crisp subject and good blown out backgrounds giving off that depth that I wanted in my pictures. You will not be disappointed with this. It worked wonders for my D3100, and now use it for my D7000 as well.
152676
I got this lens to go with a new K-1 body and it has not disappointed! It is weather sealed and I would highly recommend as a first lens on a full frame camera like the K-1. I've used Pentax manual lenses since the 70's and this lens performs even better than those, at least in terms of color and contrast, something that was expected based on the new coatings developed since the Super-multi-coating SMC days. I loved the SMC coatings and this is even better.

In terms of resolution, it is very sharp, and at all focal lengths and matches or exceeds the 36 megapixel sensor on the K-1. Very well built, no wobbles or excessive slack or looseness in the rings etc. Impressive! It is definitely way better quality in every way than plastic kit lenses on competing brands. I would say it is the 99% equivalent of a Canon standard L zoom, but just a little smaller, since it is a variable aperture lens. F3.5 to 5.6 compared to a constant F4, but then it is 10-20% lighter, which has its advantages too.

The DC motor is almost silent, much more than similar arrangements in older non ring drive lenses with competitors, and fast and decisive in focus on a K-1. The motor makes much less sound than most lens based image stabilizers, to give you an idea of how quiet.

All in all, this lens plus the K-1 is a really sweet deal for the price for what it delivers.
2721788
I've had mixed results purchasing lenses for my Canon Vixia but this one was a great deal.  When I first put it on, I was actually disappointed because there were sections of the hood showing up in frame.  This was easily rectified by loosening the screws and adjusting the position of the hood.  I recommend hooking it up to a TV and adjusting the hood so nothing shows on the edges (TV shows a wider section than the view finder).

Also, the image stabilization causes the edges to show during sudden changes in position, so you'll have to turn this off, otherwise you'll get a peek of your lens edges.

Well worth the money.  I'll use this even for photos, compared to purchasing a DSLR fisheye lens for $700.
1136903
Great bang for your buck, a great hobbyist lens! I decided on this with the crop sensor on my D3300 and I am not disappoined. A lot of people suggest the 50mm Nikkor but I decided with the difference on a crop sensor this acts more like a  true 50mm. I am very much an amateur, but I really enjoy learning on this lens. The lens hood doesn't really seem to have much effect as it is so small. The fact that you have to move to compose your shots makes shooting a little more challenging but also more interactive. I purchased this lens used for a steal, and have not been disappointed in the least, it makes me wish I had purchased a camera body without the kit lens. This lens has not been removed since I first put it on my camera. Oh well, maybe the kit lens will be sold.
329257
I bought this lens as an upgrade to the 18-55mm lens that came with my Canon EOS Rebel XTi camera.  It is quite a nice improvement, noticeably wider lens and heavier, denoting higher quality materials throughout.  I think it will be a real good "all around lens" with more zoom capability.  I have only taken a couple hundred outdoor pictures and am pleased, I havne't gotten to test out the image stabilization in low light/indoors.  Overall, I'm impressed so far and feel that I now need to upgrade my camera to the Canon 40D to get more out of the lens that I've upgraded to.
3747490
I flat-out love this lens.  I never use my kit lens anymore; this one stays on my camera and takes reliably crisp, intimate portraits.
3327843
14-45mm is hands down superior to the kit 14-42mm in construction and smooth function. My 14-42 has a stiff/sticky, cheap feeling zoom action. The 14-45mm does not leave the kit lens impression (which it used to be) at all, and is clearly of superior design and execution.  A recent trip with the 14-42 on a GX1 body, on some pretty cold days, was a bit frustrating.  Handling the camera and using the stiff zoom ring was awkward.  Even on a tripod, it was a 2 handed operation.

Optically, things are much closer.  At 12 elements in 9 groups vs 9 elements in 8 groups, you would expect superior performance from the 14-45, which I do believe it delivers in some key areas for me. Both have 7 aperture blades, but I see smoother bokeh (out of focus areas) with the 14-45mm, than with the 14-42mm.  But this, like the other optical characteristics mentioned, range from subtle to just noticeable (save for distortion and edge/corner sharpness at some settings).  That speaks pretty highly of the optics quality of the 14-42mm. Both are about equally very sharp in the center, and I'd say from looking at my images, it would be pretty hard to tell the 2 apart.  The 14-45 wins in edge sharpness, noticeably so at some lens openings.  There is some vignetting evident with both when around 14mm, but stopping down to the sharpest lens openings (5.6-8) on each helped this very much.  I think the 14-45 handles and controls flare and contrast much better, but that isn't to say the 14-42 is bad.  The biggest optical advantage I can see with the 14-45mm is the low level of distortion it produces.  I was quite surprised by this.  The 14-42 isn't terrible here either, but at each end of the zoom range, the distortion has a very strange look to it (almost like a weirdly shaped pincushion) and I had a few images that were very difficult to correct.

I feel the 14-45mm is worth the extra money if you can find a new one; even a clean used one is worth it.  If you're just entering the M43 world, foregoing a body/lens kit and buying the pieces separately would be required.  14-45mm is slightly larger size, but I don't find this to be an issue, and again, the smoothness of operation makes holding and using these small bodies a much more pleasant experience.
3727213
Great lens. The glass is a great improvement to the kit lens I've been limping along with. The range of the iris has make my work 5 times easier and higher quality.
1026840
I've been using the 70-200 f/4 for a couple of years, and realized that I really needed a faster lens with image stabilization. Justifying the price for a lens to feed my hobby was difficult, but am I glad I did!  First, this lens is larger (I had to purchase a new sling camera bag to fit the lens) and a lot heavier. I shoot a lot of action stuff, mostly ski racing, shot on the hill. This means that I can't put the camera down, or use a tripod or monopod - so the weight really puts a strain on the wrist during a few hours of shooting. But, there is no camera shake in my images. They are as crisp as is I shot from a tripod - just see the samples I uploaded.

Another big plus - I have the 2x adaptor from Canon. It was not really practical with my previous lens - slowed it down too much, required a tripod, too dark. With this lens - holy cow! Hand held shooting with a 400mm! See the samples - great quality and color.

I can't say enough good things about this lens. There are two different IS modes. Mode 1 is full stabilization. Mode 2 if for panning, say when you're following a moving skier or car.  It stabilizes the vertical but leaves the horizontal alone.  Typically an IS lens is pretty useless for action photos when you're panning the subject - Mode 2 saves the day!

The downside: The weight.  The image stabilization is loud - at first I thought the auto-focus motors were messed up.
2650446
A far better lens than the price would suggest.  I've never been a Sigma fan, but this lens changed my mind (along with its 30mm sibling).  When the camera is powered down, the slight rattle (caused, I believe by floating elements that are held in place by electromagnets) is a little disconcerting at first, but I got used to it.  Small price to pay for the excellent images.
956056
First time DSLR buyer: awesome camera and kit lens for the price.  The sensor is more than capable of producing great images.  The kit lens is actually not all that bad compared to the kit lens that came with my 50d.  The focusing is virtually silent.  The optics are not that bad.  As a first time DSLR camera / kit lens combo, 5/5 stars for most amateur applications.

Needing video capability: again, awesome camera and kit lens for the price.  It is more than capable of producing great video for most amateur applications.

Upgrading from a previous DSLR: UPGRADE YOUR LENSES FIRST.  Every situation is different.  Here is mine.  I have a 5 year old 50d that is not broken.  It still takes great pictures.  I got sucked into the hype of owning a new camera.  There certainly are improvements in the sensor and image processor, however I took pictures with identical lenses and settings on my old and new camera.  There was barely any difference unless you zoomed in to the pixel level.  Subjectively, most people actually preferred the images from my 50d (without knowing which was which).  I don't shoot video that often so that was not a selling point for me.  I returned the T5i and purchased a 24-105 f/4 L lens instead.
1034999
This lens is clearly two or three rungs above the kit lenses included with small-to-medium Nikon DSLR kits. It's heavier and feels better made, focuses quickly and quietly, and the images at all focal ranges are surprisingly sharp for a lens in this price class. I use it as my "walking around" lens, and this is the smartest lens buy I've made in the past five years -- and that's a lot of lenses!
4766273
I'm blown away with how well this lens isolates subjects of photos. I'm a novice with a d5200 and I thought that the standard 18-55mm gave pictures a decent "bokeh", that's nothing compared to this lens. It truly makes my pictures look like magazine quality without much effort.

If you are looking to buy your first "prime" lens, get this one.