I love my 50 1.8 Nikkor but that ends up being a 75mm with the crop factor. I would like to get close to a 50mm after the crop factor. The reason I was asking about the sigma 28mm is itt will aslo get a 1-2.9 magnification ratio. I do already have a mcro lens however this I thought might make the sigma a more general photo lens. The 30mm 1.4 I think has a magnification ratio of 1-10.