Lens Fungus

[Dave Throgmartin]

You definitely don't want a lens with fungus and I think you made the right call sending it back.

From what I've seen in the past 17-40 is a ways better than 16-35 I and 16-35 II is a ways better than 17-40. It stands to reason that the 16-35 I is likely a ways better than the 17-35.

Given you are using top tier optics I think you'd likely be able to tell a difference with the 17-40 and it could be marginal on performance in comparison to the others. Using anything less and think you'd be disappointed.

Dave

[peety3]

Something to consider: pick up a used lens from a rental house. Obviously, you should get to know their practices on when to sell gear, but you'll most likely have a return policy in place, decent testing before the sale to know what the optics are like, product photos to know the condition of the item, and a sense that once every 1-2 weeks they laid hands on that particular lens. I've bought two cameras (admittedly 1Dx which has a rounded-up odometer), a 300/4IS, and a Profoto D1 Air kit from LensAuthority (sales arm of LensRentals.com) and couldn't be happier; I'm saving up my pennies for another bang-up year of photographic purchases, mostly from them.