Hi this is my first post.
I have aquired a canon 5D with a sigma 15-30 lens from my mother-in-law, I like to take landscapes is this lens ok, olso I want to take family pictures which lens is ok for this.
although iv'e no experience of the 15 - 30 lens it should be fine just keep an eye on the edges / corners for vignetting
a good portrait lens boils down to how much you want to spend
money no object a canon 85mm f1.2 L but if your spending that kind of money on a lens then the studio kit to compliment it becomes a question
i would buy an all round lens such as the 24 -105 f4 L IS which compliments the 5D very nicely and is great for the odd portrait or two