Please forgive my humble efforts, I'm not much of a landscape photographer but I was on holiday in the USA last november and I really loved Death Valley. These shots were taken with my Sigma 17-70 2.8-4.5 (camera = Pentax *ist DL) and any advice, C&C always welcome E.g. - is this a good lens for landscape, I presume wide angle is better but is this wide enough? 1. 2. 3. 4. 5. 6. 7. 8.