Dust inside 85mm f/1.2

[michael_tommerup]

I have a Canon 85mm f/1.2II that I bought 4month ago.

At the back of it. The side that goes into the camera, I can see about 10 dust

particles, is that normal?

 

Regards

Michael T

[PuppyDigs]

Most lenses ship with some factory installed dust. Most folks don't notice unless they

shine a penlight down the barrel and peer in the other side. Additionally, focus

operation involves the movement of optical elements within the barrel. This movement

displaces air mainly out the rear of the lens. The constant sucking in and venting of air

is responsible for the many additional dust particles you'll find in your lens over the life

of the lenses. All lenses do this. Learn to live with it or be in continual distress.

Besides, typical lens dust makes no difference in image quality.

[michael_tommerup]

Thanks for your quick answer.

I have uploaded a pic. Where you can see most of the dust.

[Michael R Freeman]

If you can count the number of individual dust particles in a lens, you have absolutely nothing to worry about. Perfectly normal, zero effect.

[michael_tommerup]

the dust particles you can see in the pic. is just some off them, the others is out off focus

[PuppyDigs]

Is it my imagination or are some of them on the outside of the rear element?

[tim_klimowicz]

I'd imagine that the back is the best place to have dust. Light is pretty well-contained

by that point, so the effect of dust should be very minimal. On the front, though, I can

see it really causing some problems as stray light is caught, causing small flares and

just general loss of contrast as they glow.

 

Of course, this is all speculation, and assumes there's quite a lot of dust there for

anything to effect the image.

[bueh]

http://home.rmci.net/deanw/dirty_lens_test.html

[michael_tommerup]

There is no dust on the outside of the lens on the pic.i have uploadet

[canfred]

Sure there is dust its everywhere , as to your lens its worthwile to remember most particles you see are magnified after all you are looking into a lens.

does it have any influence on picture quality , not likely unless the cover is complete it will then reduce contrast.

[tony_clark]

I would send it back to Canon for a cleaning. Although, I will warn you that it may come

back worse.

[anthony_thornborough1]

I wouldn't worry about it. I remember reading an article by Dr Stewart Bell in AP when he used to place postage stamps on large (telescope-type) optical mirrors etc as a bit of tom-foolery and it didn't affect measurable optical performance a bit. Perceived optical performance would be even less noticeable.

 

Unless it's turned into an hour glass full of grit I wouldn't worry at all.

[michael_tommerup]

Thank you all for your help.

Does anybody with a new Canon L lens that have a lot of dust in it?

The ones I think about are those that are moist and dust resistant.

[anthony_thornborough1]

I can't see any in mine (ser no UV05xx) but I haven't shone a torch down it. Bought Nov 07.

[michael_tommerup]

I dont have to use a torch to see the dust, it is quite easy to see.

Ther is allmost none at the front element

[nic_brown]

My 85/1.8 has about the same level of dust after a couple of years use. Doesn't impact

on IQ, and cleaning it is likely to do more harm that good. You don't need a flashlight to

see my dust either.

 

Put the lens in your bag and think about anything but the dust. After a few weeks, you

will stop obsessing and you will be as happy as ever. It is just like the first time you

drop and ding your camera. Heartbreaking for a while, then you get over it and accept

the 'character'.

[michael_tommerup]

thank you all for your help