How does Canon Factory Service clean lens?

I just got my 500 F4 back from Canon Newport News where they did a clean and check of the lens.

My lens was, I felt, pretty clean when I sent it in, no dust, fingerprints etc.

When I got it back, the glass looked like brand new, sparkling really.

So the question is, how do they clean the glass??

The whole lens looked brand new, except for the standard paint chips, but the main front lens was just amazing. I was just curious if anyone had any idea how they went about it.

thanks in advance

GG

Awesome, what did they charge for the service?

No idea but if it was pretty clean why did you send it in?

I got a discount for being a CPS member the base charge was $299 with 30% for being a CPS gold. With tax it worked out to $224. I got it there on Monday AM and got it back Wednesday evening. They paid for the return shipping.
Not cheap, but the lens is so huge, I can see how it was quite the task to do it.

I sent it in because I had some concern that the IS motor noise was pretty loud and I just wanted to make sure that there was nothing wrong. They said it was normal for the lens, they checked all the other functions and everything was good.
After having it all checked, I doubt I will ever send it in for that again but it would be good to know how they did it.

You didn't have any complementary vouchers left to use?

I still have two of mine and I'm thinking about sending in the 85 to get cleaned.

I had the voucher but there is a charge for cleaning the larger lenses.
LOL, they did send me my voucher back though.

so no one knows how they clean the lens I take it by the replies ...anyone?

Ultrasonic cleaning maybe. Really cool way of cleaning delicate items but not sure if this is how they cleaned you lens.

I received a 135L today that had an almost clean front element. Can tell it was wiped with an oily cloth or something (I inspect with xenon flashlights).

I took out my bulb blower, my breath and microfiber, then a lenspen to clear the oils and a final wipe with a brand new microfiber. Looks as mint as can be. Factory Fresh!

I am guessing Canon uses compressed air, cleaning fluids and lint/oil free cloths. If not disposable cloths to prevent oil transfer and such.

Dude - no one knows...

You'd be surprised what lens paper and a clean environment can do for lenses.

If I have to guess, it has to be done in the special lab and dust-free. Probably similar to where they assemble the lens. If you want to be wild, it probably is handled by a robot than human being

Not sure robots are at that point where you can furnish and program them cheaply enough to do the delicate tasks a person with good eyes can. Robots currently (well, maybe this is the 1980s view I guess) would just clean the whole thing without a care for what parts actually need it. Maybe in the near future, though. Up to this point, there do seem to be a lot of checklists involved with a lens teardown that a person can do efficiently and with more care for details: Does a robot know how to judge an IS system for sound, does it have an electronic testing bench to plug things into (which of course makes the range of motions even more complicated), and to do this for the entire supported range of EF lenses? Don't think so.

two q-tips and a bar of soap.