Internal dust 17-85mm

<p>I have a EF-s 17-85mm lens and there is some internal dust. I noticed there is a small hole on the metal ring that fits over the glass on the front of the lens. Does this ring screw off to remove the glass and clean the interior of the lens? If so, how do I safely unscrew it, if not what is it there for and how can I clean internal dust?<br>

No, it doesn't affect my images, but I can see the dust and I don't like it.</p>

<p>Taking apart any zoom lens is a really serious undertaking, since you have to make sure to get it back just exactly. I doubt the dust is only in between the first and second elements anyway, even if you could get the front element off. I know I wouldn't mess with my 24-105.</p>

<p>If it really bothers you, I'd suggest having a cleaning-the-lens estimate from some authorized place, and you may come to find the dust more "likeable".</p>

<p>Normally this is more of a problem with lenses that "pump" and "suck"* in and out as they focus, but internal movements are still taking place inside the 24-105, and that can always suck in a speck or two. Regardless of other issues, this can be one advantage to having a filter on the front to help seal the lens a little. Canon and other manufacturers actually recommend this for some lenses.</p>

<p>*Of course, some lenses suck more than others.</p>

<p>You will probably find dust inside any lens if you look hard enough. The best approach is to stop looking.</p>

A bit of dust inside the lens isn't going to affect the image; just ignore it.

<p>Ignore it. You'll likely do more damage to the lens attempting to remove it than damage to your images by leaving it alone.</p>

<p>Even if you did remove all the dust, new dust would replace it very quickly.</p>

<p>The lens has to breathe when you zoom in and out. This sucks in ambient air and associated dust.</p>

<p>I have never noticed small dust particles causing any visible effect on images.</p>

<p>Henry</p>

<p>I have a speck of dust once on my 50mm 1.8 mk1, It was located on the center portion of the lens. I just pumped some air on the rear of the lens, Then the dust was gone , Must have transfered to a place I cant see.</p>

<p>I once used a 17-85 that somebody had 'repaired & cleaned' the whole upper left corner had a slight distortion to it at anything wider than about 35mm. Smeared just the one corner, and just enough to ruin every picture taken w/ it...</p>

<p>My vote is always go for it... life is about the journey afterall! you just might want to be ready to buy a new lens afterward... :-)</p>

<p>I recently had a 3 year old 17-85mm returned from Canon service in Irvine in better condition than when I purchased it. The lens when new had considerable dust (no problem with image quality) and when returned it was perfect! Zero dust! I needed repair of the AF module or something like that and when I opened the box it looked like a new lens. I even checked the serial number to be sure it wasn't new. I have never had a lens so clean inside. The repair was $95 with parts and shipping.</p>