Summary: Excellent but to heavy it weights, but its fast and usefull ,its a smart lens i can take pictures in every condition ,it hunts only you have difficult situations like some light ray between your position and the target nad not always, and man you can see the stars trough this lens ,great quality ,only deffect is that its to heavy good manual focusing perfect for my t3i -sometimes to refractive
Summary: I am a professional filmmaker and the majority of the video I shoot is with Canon 5D mkII DSLRs. I first purchased this lens used on craigslist. After using it a couple months I dropped it from 6 feet to concrete. It didn't survive, nor should anyone expect it to!!! However, I loved the lens and immediately bought another from B&H to replace the broken one. Since then I have bought 2 more for a couple other rigs. This is my primary lens for shooting events.
Summary: I ran the 28-70 2.8 through the paces and it's off to SIGMA for calabration after one day. I read many reports of focus issues from 2.8 through about 4.5. I rolled the dice and lost. The autofocus missed on 99% of the shots running up to about f 4.5. From f4.5 through f-11 the images improved as expected. The build seems very good, just a calibration in my case ( I hope ). I will let you know with an update once the lense comes back from service.
Summary: I bought this lens to shoot sports and weddings mostly. I was so unhappy. The first time I used this lens, every picture was blurry. I takes the lens several tries to autofocus and even then...doesn't always work. I'm really not happy at all. I should have saved my money and bought the Canon one...even though its double the price.
Sigma 28-70mm f/2.8 EX DG review by theflyingmoose
15 February 2009
Summary: As a replacement for a kit lens (even one that was as reasonable as Pentax's 18-55), this lens seems worthy of my investment. While I'm used to really sharp images through my elderly 50mm prime, changing from regular use of a kit lens (it being convenient and auto-focus) was an eye opening experience. This said, it is soft at f/2.8, not very badly, but enough that stopping down is usually in order.
Pros: good value, decent optical performance, seems sturdy
Summary: I keep this lens on my camera (Rebel XTi) almost all the time, and use it for almost everything. It's fast enough to catch my kids in action, very good in low light, and also create great bokeh for portraits. It can get a little heavy so holding it for long periods of time can get tiring. I highly recommend this lens.
Pros: Consistent Output, Sharp Focus, Strong Construction
Summary: I was a little hesitant to purchase this lens because there were only 4 reviews. But I have to say this lens performs very well. The focus was much better than I expected. Out of 250 sports-fast action shots, about 8 were out of focus (would have been fewer but I was in continous shot mode). I am very pleased with this purchase, especially for the price. This lens will stay on my Nikon D80 as my all-around lens.
Summary: The images produced with this lens are sharp and detailed almost beyond belief, and there is little or no distortion throughout the zoom range. It has a sturdy and solid feel, the only slightly irritating physical feature being an inconstant tension on the zoom ring. There are two significant flaws. Firstly, the images are over warm and contrast is too high. This isn't as easy to correct digitally as one might think. Secondly, autofocus is poor.
Cons: Blurry Focus, High contrast, Poor autofocus, Warm colour balance
Sigma 28-70mm f/2.8 EX DG review by thomasjohnlynch
6 January 2009
Summary: Being new to SLR 35 and having just an XTi I am very nervous about wasting cash or not getting any value or return on a "toy part" for this hobby. I took about 2,485 pictures last year and have save and been taking digitial photography since the mid 90s when my son was first born. I have been swapping out the plastic freebie and bought a Sigma 70:300 zoom for outdoor sailing and wildlife and now picked up this lens for close up and indoor and flash.