Lenstip reviewed the Sigma 18-35mm f/1.8 DC HSM lens, the UFO: Unbelievable F-stop Object. As you most probably know if you live on this planet, the Sigma 18-35mm f/1.8 is the first zoom lens for APS-C DSLR to deliver constant f/1.8 over the whole zoom range. As if that wasn’t amazing enough, Sigma managed to give a more than fair price to this lens: $799, while most people was expecting a price tag at least over $1000. So, the suspect was Sigma could have had to make some compromises on some aspects of the lens. Nope. The featured review shows once more how outstanding the Sigma 18-35mm f/1.8 is. Read more after the break.