Advice on a sharp zoom

Stan Borzhemsky wrote:

I know, I'm terribly late to this thread... The dust has settled and the OP came out with a screw-drive Pentax 16-50 (as well as a Tamron 70-200).

I really enjoyed reading the insightful comments regarding many Pentax mount zooms, both short and long. But it did strike me odd that the Sigma 18-35 wasn't mentioned even a single time. It's a stop and a third wider than the 16-50, has a more reliable - or, shall we say, less unreliable - AF motor, and is very well-regarded for its IQ. What it gives up is weather sealing and a bit of range.

Had it not been for the lack of weather sealing I would have gone with the Sigma instead of the 16-50. Personally, I don't actually feel that the focal range is such a great sacrifice because I tend to shoot closer to the wide end. This may be different for the OP - although to be fair bringing the FA43 to cover the difference wouldn't break the back weight and size wise. I would regret the 2mm on the wide end but when shooting wide, I would tend to use the 10-20 (that the OP also has) for more compositional flexibility.

That's an incredibly interesting lens, and I hadn't actually heard of it previously.  I didn't know it was actually physically possible to make a zoom faster than f/2.8!  That's pretty remarkable just in terms of engineering!

I'm not sure I'd have bought it anyway.  I wanted WR, and for me the longer end is extremely useful.  In fact, I generally hate 35mm as a focal length.  Everything in the 30's bores me and I just don't use it.  I use the 40's, I use the 20s, I use the teens, I use the 50's.  I like the 70's purely for portraiture.  30-39mm, 60-69mm I just get terribly bored with

But the speed on that thing sure is impressive.  Though I do find such fast lenses almost impossible to control DOF on without stopping down anyway.  At least wide lenses.  40+ the tele angle and compression makes it easier to isolate.

Sort of ironic, the one thing that appeals to me about FF is the extended DOF control.  And yet I don't think it's as advantageous as it sounds since it would then be "too much of a good thing" for most of my shooting.  If I did portraiture it would be great.

Great lens though, and despite it being too late for me (and I probably wouldn't have picked it anyway) I'm glad you mentioned it!