7D vs......get this a 1D mkIII

[neuroanatomist]

I don't understand this comment. The 1D has a wider field of view than the 7D on the same lens?

Yeah, but the 7D uses EF-S lenses, the 1D cannot. So for rectilinear lenses from Canon, you can get 10mm on the 7D (16mm FFeq), but with the 1D your widest option is the 14/2.8 (18mm FFeq).