Sigma's certainly managed to get plenty of photographers' attention with its line of Foveon sensor-equipped digital cameras, but it hasn't exactly always managed to meet expectations. According to Photography Blog, it looks like that's also the case for the company's latest: the SD15. While the camera is described as 'less of an obvious odd fish than its forebears," the site says that it's still best suited for photographers looking for a "challenge," and that you likely won't want to have it as your only DSLR. In particularly, Photography Blog found that while images exhibited less of the odd color casts and white balance i