HOW does dust get IN a non-extending prime lens?

tkbslc wrote in post #8249204
I'd rather see dust than flare and ghosting....

Agree. You're preventing a dust "problem" that you'll never ever notice by adding a real image-quality issue if you're not using quality filters.

gnomes and elves? who forgot the fairiess?!

I dont think a few specks will change that much, from what i hear its a marvellous lens and the odd dust bunny will hardly if at all affect IQ

I wouldn't worry about that so much:

http://www.lensrentals​.com …0/front-element-scratches

Whoa, That’s quite the front element on that one. It would be interesting to see in the test what the lens would perform like if it was only the front element with no internal damage. Puts having a little nick into perspective anyways.

Cheers,

zoom_zoom wrote in post #8249199
I hate seeing dust in any lens I own (regardless of whether it affects IQ or not).... I always use a UV filter on day one.

A UV filter will not prevent dust from getting in,..
Dust never comes in through the front,.
It comes in through the rear.

RDKirk wrote in post #8246934
Lenses are not assembled in a "clean room." The assembly areas are no cleaner than a normal Japanese office environment.

I seriously doubt this.

Madweasel wrote in post #8251636
I seriously doubt this.

Go to the Canon Camera Museum site and look at their slideshow. The lens assemblers aren't even wearing hairnets. They do wear little finger gloves, though.

OK, well I went to look at that (a long time since I saw it before) and had a close look at what the people were wearing in the assembly room. The female assembler of the 500/4 was wearing a hat, but you're right it didn't cover all of her hair. However, they were clearly wearing special clothing to eliminate dust introduction and I would say although maybe not space-industry clean-room standards, it was a much cleaner environment than a standard office. I'm prepared to meet you half-way on this one