The-Digital-Picture have reviewed the new Sigma 18-50mm F2.8 EX DC lens.

“The Sigma 18-50mm f/2.8 EX DC Lens’ AF sound is relatively quiet but not silent like an HSM or USM lens. AF speed is on the slow side of average. AF accuracy was also on the low side of average. When shooting the very well-lit ideal focus point on ISO 12233 chart tests using AF, every other image was completely out of focus at 18mm f/2.8 and AF was inconsistent at 24mm. In real world use, I missed a noticeably higher number of shots than I should have. AF performance was especially poor in low light (where focus hunting is frequent). Results were also poor in AI Servo mode.”

Website: The-Digital-Picture - Sigma 18-50mm F2.8 EX DC Lens Review