Tamron 17-50mm f/2.8 ???

[Nikonfreak]

Originally Posted by cyclohexane

Usually I answer "Yes", but it's really up to you. When talking pro glass like the 17-55mm f/2.8, you're really paying for the build quality as compared to third party options, not optical quality.

Not entirely sure. There's light falloff in the corners, aberration and distortion. Sample variation is also an issue when the build quality isn't up to par. When I owned a 28-75 f/2.8 Tamron it was good for a while and then after serious use began to deteriorate and have issues.

So you do pay for a bit more optical quality and therein lies the difference. At $400-500 price point you can forgive some quality concerns. At $1,200 - 1,600, you won't.

Julio