I am not a professional but this is a great lens you can beat it for the price
581978
I am not a professional but this is a great lens you can beat it for the price.  Definetly works as described.
771286
Not a lot I can say about this lens other than it is typical Canon in that it does what it is supposed to. You get more than what you pay for with this lens because of the auto focus feature. Not all telephoto lenses are equal especially not equal to a Canon. I highly recommend this lens.
3643433
This is a great lens if you want to save a little bit of money from the bigger name brands.
1981281
Great lens! It may not be the ultimate, but for my purposes it does the trick.
2719659
Okay so I'm no professional but I love taking photos. I cannot talk about all the technical aspects of this camera in great detail but what I do know is this:

This is a great addition to a person looking to buy a second lens for a DSLR camera. I have one of the Canon EOS rebel cameras and have always used the standard lens it came with. On a recent trip, I noticed that this lens lacked the ability to go close enough for my liking and so then I researched different lenses and finally decided on this one.

The best thing about this lens is it's ease of use - I zoom in on what I want to take a picture of, click and it produces stunning pictures. I recently used it at a soccer game to grab some of the action. The photos came out amazingly and I was very pleased. Again this has nothing to do with my talent, the lens is just great at getting pictures.

I bought this camera for a bargain $140 from Amazon on December 19th 2011. I notice it's now $200 so it might be worth you waiting until the price comes down again.

As I said earlier, I'm no professional but if you're a keen amateur like myself, who is in the market for a great zoom lens, then you can't go far wrong with this one!
4371537
The best value in the lens market although this is not the kind of lens that suits for every situation, is a great lens to low light conditions where you don't need a zoom or a macro
3639518
This lens has excellent image quality, sharpness and colors. The build quality is not top notch but for this price who cares?
4912476
I'm just a beginner when it comes to anything photography, and I think that's exactly who this lens is catered to: the beginners and occasional novices who need extra reach. One of the reasons I got my DSLR in the first place is because I was tired of lugging around both my Canon Rebel XS and my HD Sony camcorder and having to constantly choose between great picture and no video option vs. OK picture with great video. My Canon T2i covers the great picture and video aspect, but I was missing out on the zoom. Because of that, I picked this lens up and it makes a great compliment to my kit 18-55mm lens for the times that I need that extra distance. For the price ($199.99 at the time of this review) you can't go wrong if you are looking to expand your lens collection without breaking the bank.
2515887
As a hobbyist I can't comment on the technical aspects of this lens, but let me say I love the pictures produced.  On my D7000 I use the M mode.  You will need to adjust the shutter speed on the camera and the aperture ring on the lens.  You will wind up with some pictures over and under exposed as you get used to it, but play around with it and you will get the hang of it in no time. The focus is also manual but I find I don't even touch it very often.  You will need to keep the hood properly aligned or it will appear in the borders of you pictures.  You will need to put the lens cap on when not in use to prevent scratches on the glass. A Fantastic value!
701510
For the price this lens is outstanding. the focus is a tad slow. The chromatic aberration does not seam to me to be an issue if you are shooting at f/8 but it can get a little strong at the ends of the apertures.
676483
If you know what this lens is and what it is capable of, it is a great lens. This lens is a great way to see if you want a huge tele lens without a huge investment. When the light is perfect and the subject is still, the quality is very high considering the price. It gets really weak under low light, but the for the price it is great. It is also well built-all metal casing and real glass. It works great as a telescope and I have captured some good moon shots with it. I recommend this lens, but read up on what it is and what it is not.
2703642
At first i was skeptical on how good a $100 lens could possibly be. I wondered if it would just fall apart or not focus maybe have really bad picture quality after all how good could a $100 lens actually be.. Well upon getting this awesome little lens (yes it is actually really little on my Canon 70D)  and I was truly amazed on what I could do with this lens and its 1.8 F-stop that lets in so much light that you can actually take pictures in really low light that were impossible with normal lenses at any decent speed or hand help .

I used this for taking pictures at a party event and it literally saved the day (late afternoon to be exact) the party hall lighting was really dark and pictures were terrible even with my canon 24mm-105mm L (is) lens and iso 3200 all pictures were Dark and if i adjusted the shutter speed to compensate the pictures were slightly blurry. There was just no way to get a decent picture without stopping people and making them stand perfectly still or using a Flash.

The photos were really good for the low light situation that I encountered out of 80 pictures I got about 32 really good photos

a few things I did notice is that the auto focus is fairly slow and loud (it does have a harder time to focus in most situations)
the build quality is OK not good and I wouldn't rely on this lens as my primary for a major trip somewhere.

Other then that This lens is really good and should be in every Canon SLR camera owners bag as a good backup lens at the least. as with all lenses this has its place and usability along with restrictions but for the price this lens is well worth it and you will not be unhappy with this lens
885626
This is a great lens for the price. It should be a crime for a Canon owner not to have one. Unless you want to step up and get the f/1.4 . Great for portraits and low light situations.
3511659
Undoubtedly this is one of my best investments.. I love this lens. I have APS-C camera and hence the 50 mm lend is effectively 80 mm for me. Yet it is good enough for most clicks. For group clicks you just need to go a bit far. Other than that this is an awesome lens. That too for such cheap price. The shallow depth of field (thanks to f/1.8) brings out beautiful bokeh and thorough out of focus background.
880409
Great lens for the price.  Proves you don't have to spend big bucks for a lens. It's been my go to lens for birding. Love it
817396
This lens is perfect for beginners who are looking for a good lens for cheap. The Sigma 28-70mm 2.8 gives the shot pretty good bokeh (depth of field) when at 2.8. The focal lengths are pretty good too. 28mm gets some fairly nice wider shots and the 70mm gives it a small zoom capability. The auto focus is rather quick. My only downside is that it feels a little plasticy but it does have a nice sturdy feel to it. I highly recommend.
3156038
This lens is amazing for the price. I use it for product and portrait photography, and it makes my images look much more professional. Some images are attached as samples.