dust & lenses

[AjP]

may be it is dumn question but... since I got some dust inside my 28-135 lense I'm worndering if all L lenses are dust proof???? since I'm going to buy few L lenses in the close future.

thinking about
16-35 L 1.8
24-70 L 1.8
70-200 L 1.8
might get 1.4x extender

just hate to spend so much money and then have no idea how to clean it.
I have only one body so I'm switching lenses a lot

thx

[richardho11]

may be it is dumn question but... since I got some dust inside my 28-135 lense I'm worndering if all L lenses are dust proof, since I'm going to buy few L lenses in the close future.

thinking about
16-35 L 1.8
28-70 L 1.8
70-200 L 1.8
might get 1.4x extender

just hate to spend so much money and then have no idea how to clean it.
I have only one body so I'm switching lenses a lot

thx

I have the 24-70L and the 70-200L and neither one of them have dust in them yet. Thank god. Actually, all the newer lenses 24-70L, 70-200L IS and 16-35L are said by canon to have seals to prevent dust in them. So Im assumming that the previous versions although built well, might be prone to dust. Especially if your taking photos in a windy / dusty situation. Also, where are you getting all those L zoom lenses from with the f/1.8? I would love to trade mines in for those!!! haha. ;)

[AjP]

I have the 24-70L and the 70-200L and neither one of them have dust in them yet. Thank god. Actually, all the newer lenses 24-70L, 70-200L IS and 16-35L are said by canon to have seals to prevent dust in them. So Im assumming that the previous versions although built well, might be prone to dust. Especially if your taking photos in a windy / dusty situation. Also, where are you getting all those L zoom lenses from with the f/1.8? I would love to trade mines in for those!!! haha. ;)
ooopppsss mistype, sorry, ha ha ha 2.8L

[rent]

i'd think the push-pull type of zoom (100-400mm L) are more prone to suck in dust. but i haven't noticed any problems with my 16-35, 70-200/f4, 180 or 300/f4.

as far as image quality is concerned, a speck of dust won't affect quality at all. but it's just annoying knowing that it is there.

-alex

[ron chappel]

Any lens that changes length will eventually suck in some dust ,not just the push-pull types.
A lens can only be sealed when there is no length change at all which means it has to have both internal focus AND internal zooming.I (think) both the 24-70/2.8L and 70-200/2.8L are this type

[Jon]

I'd go even further than that - if the rear elements move, there's an opportunity for them to pump air into/out of the lens. If the lens doesn't change length, ever and has a fixed rear element as well, it won't suck air in except possibly through the zoom and/or focus control rings.