So, I have a friend who shoots with a Nikon full-frame camera. She does food photography mostly (has a nice blog) and typically uses a 24-70mm constant f/2.8 zoom lens for her work. I know that due to the crop factor that would equate to a 12-35mm lens on :43:, but what would be the equivalent max aperture? Is it also halved, so would be f/1.4? Or to turn it around somewhat, the new Panny 12-35mm f/2.8 zoom would be like using a 24-70mm f/5.6 lens on a full-frame camera? Please correct me if this is wrong, and let me know how to figure out the math, or point me to a tool I can use to do it. Thanks!