Dust inside lens

How does the dust get inside of a lens and is there away of cleaning it?

How does the dust get inside of a lens?

 

Physics. Think about it for a minute. Any prime lens that is not internal focus (which, except for telephotos, is most primes) changes VOLUME as you focus. Most zooms change VOLUME as they are zoomed. Change in volume means an air exchange (otherwise the lens tube would be under pressure or vacuum) with concurrent dust exchange.

 

Any lens can be disassembled and cleaned. It will get dust in it again (and very soon).

Wade, dust inside won't make any noticeable difference to your photos since it is in an out of focus area - it's when it is on the focal plane (ie sensor) that you have to worry - and even then only when stopped way down.

My 24-70 f/2.8L Lens has ZERO dust. My previous IS zoom lens had so much dust I had it replaced, and it filled up with dust again in two months. So the lens certianly makes a difference.

 

Every time you zoom, you draw air into the lens (laws of physics), and with that air, dust.

 

IOt does not matter to image quality, generally. But it is very annoying nonetheless. The 24/70 f/2.8L is great, is all I can tell you.

What others said. Try this neat trick - cover your lens' front element with a small piece of paper (fingernail-sied, don't glue, point it upwards if you can). Then check through the viewfinder - you can't see it!

 

Cheers