Originally posted by ihasa - If you must have FF, and have the $$$ and the strong shoulder muscles required, other brands have some excellent offerings and maybe Pentax one day will too
Thank you for trying to bring politeness back to all of us.
Every time I go to look at the data behind the quoted statement above I come away with a different opinion.
At mid range focal lengths, say, 24-200mm (35mm equivalent), FF lenses that produce an equivalent DOF are slightly lighter, slightly cheaper, and slightly smaller than APS-C lenses.
Of course, slow lenses in FF are not nearly as widespread as slow lenses in APS-C (where's the 23mm f/6.2 that's equivalent to the 15mm f/4?); or conversely, fast lenses are not available in APS-C.
I think this is another advantage to FF, in that you can choose whether you'd prefer
1) slightly cheaper, slightly smaller, and slightly faster (i.e. 24-105 f/4 instead of 15-68 f/2.6)
or
2) (much) more expensive, larger, and much faster lenses. (i.e. 24-70 f/2.8 instead of 15-45 f/1.8)