Replace or Augment EF-S 15-85mm f/3.5-5.6?

[EricPvpi]

You might consider keeping your existing lenses and adding a fast prime for the shallow DOF and indoors shots. I'm very happy with the Sigma 30 f/1.4, which frames at just shy of 50mm on a FF body. It's a great workhorse lens that can be used in so many ways. Then you can keep the excellent 15-85 for outdoor use.

Thanks. Was considering that as well. I wasn't sure yet on a fixed length since I chase 3 kids around and the zoom is nice indoors. But I was thinking about doing this as well with a fixed between 28 and 50mm. I am not sure why Canon doesn't have an EF-S 30, I think they would sell well.

Overall, I am just trying to think through what I want in the 17-50mm range as well as the 50-80mm range.