腾龙要好很多很多·

15-30值得购买

佳能吧，好歹有个35焦段。人像时也能照顾过来。

看大家的评价大相径庭，有点好奇，在网上查了查，发现lensrental网有一篇比较详细的评测。评测的结论比较好玩，在广角端，腾龙镜头在中心略差于佳能和尼康14 24，在离中心1/3处，腾龙略好于佳能和尼康，腾龙的边缘画质比较差。在长焦段，腾龙仍然是边角较差。在23mm焦距处，腾龙与尼康可比拟，显著好于佳能。从重量角度，佳能1.4磅，尼康是2.2磅，腾龙2.4磅。腾龙当然比佳能和尼康便宜很多。

​摘录几条结论，比较好玩，供大家一笑：
​在广角端：
I won’t call it a tie because they are different. A landscape shooter for whom the corners are critical might prefer the Canon. A wedding shooter needing the middle of the image for group shots might like the Tamron better.

Overall at the wide end the Tamron does well. It’s perhaps not quite as good as the two manufacturer’s zooms, but very close.

在长焦端：
At the long end, it’s apparent that the Canon is just a bit better than the Tamron both in the center and off-axis.

Again, the comparison shows that the Tamron just isn’t quite as good as the Nikon at the long end.
 ​
在23mm处： 
The Tamron is at its best here in the middle of the zoom range, with a better MTF curve than at either extreme. The Canon, on the other hand, appears to be at its weakest here; not as good as it is at either extreme and not as good as the Tamron at 23mm.

Compared to the Nikon, the Tamron is holding its own when shot at 23mm with an MTF curve that’s as good as the Nikon’s, and perhaps a bit better since it has less astigmatism. That’s pretty remarkable.

本版也曾经转载过三个镜头的另一个评测：http://bbs.fengniao.com/forum/5274690.html

文版的评价是，评测结果与他的感觉有出入，腾龙显著好于canon。对比lensrental的评测，文版的评论是对的，因为文版是婚礼摄影师，当然喜欢腾龙

楼主问的是佳能16-35F2.8，这个头不怎么样，也用过。应该腾龙2.8的要好些。说实在的，16-35F4比F2.8好一些，肯定比腾龙那个要好。但是还不尽如人意。还没有24F2.8定焦成像好。我用5DS试的，回来在电脑上做过对比。