Quote Originally Posted by Brendan7


"EF 17-55mm f/2.8 IS USM dust issues" pulls up 12,000 results on my browser.


"EF 24-105mm f/4L IS USM dust issues" pulls up 610 results on my browser.


Wow - what search engine are you using? Bing-o? [:P]


I get ~5,200 and ~3,700 respectively in Google (I added the -S to the 17-55mm) for the same search terms (without the quotes).


Nevertheless, you're absolutely correct in that many people have apparently had dust issues with the 17-55mm, and the 100-400mm, and the 28-135mm, and many other lenses, moreso than with the 'weather-sealed' L-lenses, on average.


Quote Originally Posted by Brendan7
the 24-105 isdust and moistureresistant.

Yes, it is. Resistant ≠ impervious. It's a zoom lens. The barrel extends and retracts, changing the internal volume of the lens. Therefore air must move in and out of the lens, unless someone changed the laws of physics when I wasn't looking. Air contains dust. Moving air moves dust. Moving air into the lens can move dust into the lens, and that dust may settle there. It doesn't really matter if it's a 100-400mm push-pull zoom or a 'weather-sealed' 50L with the only the focus elements moving. I've run across reports of dust in the 100mm f/2.8L Macro IS - that's a 'dust and moisture resistant' lens with completely internal focusing - but air (and apparently dust) can still get in.


Regardless, I think you may be unfairly judging an excellent lens, which Bryan calls, "...one of the best general purpose lenses available." If mine was filling up with dust, I'd certainly feel differently! Obviously, choosing a lens is a personal decision, and if you don't want one, don't buy one! I've read a number of POTN and FM posts from people who indicate that lens is their sole reason for keeping a 1.6x body. I'll keep my EF-S 17-55mm f/2.8, thanks.


But then again, I like my EF 24-105mm f/4<span style="color: red;"]L a lot, too - especially when I'm going out in the rain. [] (In fact, a couple of days ago I was shooting pics with the 17-55mm of my daughter running around the yard when I felt the first few drops of what became a nice, cooling rain shower on an 80&deg; day. She wanted to stay out and play in the rain - how come we grown-ups forget how fun it is to jump in puddles?? - so I ducked inside to swap on the 24-105mm, then went out and kept right on shooting.)


Thanks also, Brendan, for your suggestion of 24-105mm + a UWA - that combo vs. the 17-55mm will be a tough decision for an upcoming trip.