Originally posted by carlosodze
4700 the cheapest, do you know if there is any comparison between the sigma and the pentax? the sigma is faster, pentax a little longer, lighter and WR, so i am not sure...
Never used the Pentax.
Pentax Pros: WR, very slightly longer. A tiny bit lighter (but this almost certainly doesn't matter, because)...
Sigma Pros: Easier to handhold (much shorter, better weight distribution, very marginally heavier), faster (incredibly important if you want to use a T/C).
In a perfect world I'd look at the bokeh and sharpness and would likely choose the Sigma... but really execution counts for a lot, so it's tough to tell without using them both.